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Fetal infection of bovine viral diarrhea virus (BVDV) before d 125 to 150 of gestation results in the birth of immunotolerant, persistently infected (PI) calves. Infection of BVDV during late gestation results in transient fetal infections (TI). Unvaccinated, yearling Hereford heifers (n = 25), seronegative for antibodies to BVDV1 and BVDV2, were bred by artificial insemination with X chromosome-bearing sperm from an Angus sire to examine the impact of TI on postnatal growth, estimated dry matter digestibility, blood glucose concentrations, and carcass characteristics. On d 175 of pregnancy, heifers were intranasally inoculated with either DMEM + 2% horse serum (sham control) to generate control calves or 4.0 log TCID50 noncytopathic type2 BVDV to generate TI calves. All sham-inoculated control dams remained seronegative, and all BVDV-inoculated dams seroconverted by d 14 post-inoculation. Sham-inoculated control dams (n = 12) and BVDV-inoculated dams (n = 12) gave birth to live calves. All control offspring were seronegative, and all TI offspring were seropositive for antibodies to type 2 BVDV at birth. All offspring were raised on pasture until weaning. At weaning, all calves were transported to our feedlot research facility, housed in one group feedlot pen, and transitioned to a high-energy concentrate-based diet until reaching an approximate BW of 600 kg. Upon arrival at the feedlot, all animals received a standard heifer growth implant, a modified live viral vaccine containing IBR-BRSV-PI3 and were dewormed. Heifer BW and jugular blood samples were collected every 28 d. On d 84 of the feeding period, titanium dioxide was added to the diet of 12, age-paired, individually fed, heifers (3 control and 3 TI heifers; approximately 1 yr of age) for 28 d and used to estimate dry matter digestibility. After approximately 280 d on feed heifers were transported to a USDAinspected abattoir and harvested. The TI heifers hadlighter birth weights (P < 0.03) and final BW (P < 0.04) when compared with control heifers. Average daily gain was greater (P < 0.01) in control compared with TI heifers. Blood glucose concentrations were similar between control and TI heifers at all sampling time points. Dry matter intake of individually fed heifers was similar across treatments. TI heifers had a 2.2% lesser (P < 0.05) dry matter digestibility and lighter (P < 0.01) hot carcass weights compared with controls. These data suggest that TI fetal BVDV infection negatively impacts growth throughout the feeding period, possibly by impacting gastrointestinal tract function. This research was supported by USDA-NIFA Grant # 2019-67015-29866. [ABSTRACT FROM AUTHOR]

This study investigated the effects of injectable vitamin C (VC) at weaning and prior to transit on growth performance and immune function in early-weaned beef steers. On day 0, 91 Angus × Simmental steers (92 ± 4 kg) were weaned (65 ± 11 d of age), given vaccination boosters, blocked by age, and randomly assigned to weaning (WEAN) treatments: intramuscular injections (20 mL per steer) of VC (250-mg sodium ascorbate per mL; 5 g per steer) or saline (SAL). From days 0 to 48, steers were housed at the Dixon Springs Agricultural Center (Simpson, IL) in pens (six pens; N = 14 to 16 steers per pen) equipped with two to three Vytelle bunks to measure individual daily feed disappearance. On day 49, half of the steers in each WEAN treatment were randomly assigned to an additional injection treatment (20 mL per steer) of VC or SAL prior to transport (TRANS). After administering pretransit injections, all steers were loaded onto a commercial livestock trailer with equal representation of treatments across compartments. Steers were transported for 6 h (approximately 480 km) to the Illinois Beef and Sheep Field Laboratory (Urbana, IL). Upon arrival, steers were sorted into pens (six pens; N = 13 to 17 steers per pen) with 2 Vytelle bunks per pen. Steers were weighed on days 0, 1, 14, 48, 49, 64, 78, 106, and 107. Blood was collected (WEAN = 24 steers per treatment; TRANS = 12 steers per treatment) on days 0, 1, 2, 14, 49 (pre- and posttransit), 50, and 51. Data were analyzed using the MIXED procedure of SAS 9.4 with fixed effects of age block, WEAN, TRANS, and WEAN × TRANS. Plasma ascorbate concentrations were greater (WEAN × time P < 0.01) on days 1 and 2 for steers that received VC at weaning. Similarly, for steers that received VC on day 49 pretransit, ascorbate concentrations were greater (TRANS × time P = 0.04) on days 49 posttransit, 50, and 51. Treatments did not affect (P ≥ 0.13) body weight, average daily gain, or gain to feed throughout the trial. Serum Bovine Viral Diarrhea Virus type 1 and 2 antibody titers on days 14 and 51 were not affected (P ≥ 0.32) by treatment. Injectable VC administered to early-weaned beef steers at the time of weaning or pretransit increased plasma ascorbate concentrations but did not improve growth performance or antibody response to vaccination booster. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to determine the effects of increasing trace mineral (TM) supplementation on finishing cattle performance, carcass characteristics, TM balance, and antibody concentrations. Commercial Angus steers (n = 240; body weight, BW = 291 kg ± 27.4) were stratified by arrival BW and source and randomly assigned to 1 of 4 experimental treatments in a randomized complete block design (12 pens/treatment; 5 steers/pen). All steers underwent a TM depletion period for a minimum of 42-d prior to the administration experimental treatments. Treatments included a negative control (CON) in which cattle received no additional TM supplementation or TM supplementation treatments in which cattle received added Co, Cu, I, Mn, Se, or Zn from inorganic TM sources at 2016 Nutrient Requirements of Beef Cattle (NASEM) requirement levels (1X), at 2 times NASEM requirements (2X), or at 4 times NASEM requirements (4X). Selenium was included at 0.1, 0.2, and 0.3 mg/kg for 1X, 2X, and 4X respectively, based on federal law. There was no difference in overall BW, average daily gain (ADG), dry matter intake (DMI), or gain to feed (G:F) due to TM supplementation (CON vs. SUPP P ≥ 0.47). There was no difference in hot carcass weight, rib eye area, fat thickness, dressing percentage, marbling score, or USDA Yield Grade due to TM supplementation (CON vs. SUPP P ≥ 0.30). One steer was chosen at random from each pen to be evaluated for serum and liver TM status and antibody concentrations to common respiratory viruses. There was a treatment × day interaction for serum Co and liver Cu and Se (P < 0.0001). Serum Co was greatest for the 4X treatment from d 28 through harvest. Liver Cu was greatest for the 2X and 4X treatments from d 56 through harvest. Liver Se was greatest for 2X and 4X from d 28 through harvest. Serum Zn was greatest for the 4X treatment (P = 0.02). There was an effect of day on liver Co, Fe, Mn, Mo, and Zn (P ≤ 0.0001) and serum Cu, Mn, Mo, Se, and Zn (P ≤ 0.002). Concentrations for individual TM had different trends over time, however, all reported values were within normal ranges. There was an effect of time on bovine viral diarrhea virus Type 1A, bovine herpesvirus type 1, and bovine parainfluenza 3 virus antibody concentrations (P ≤ 0.0001). Supplementation of TM above NASEM requirements did not affect overall cattle performance, carcass characteristics, or antibody concentrations, but did affect the storage and circulation of certain TM. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to examine the impact of dams infected with bovine viral diarrhea virus (BVDV) during late gestation on inflammatory blood biomarkers in their offspring. Fetal infection with BVDV before d 125 to 150 of gestation results in the birth of immunotolerant, persistently infected (PI) calves. Infection of BVDV during late gestation results in transient fetal infections (TI). It was hypothesized that offspring of dams transiently infected with BVDV on d 175 of gestation would have greater inflammatory blood biomarkers than control offspring. Unvaccinated, yearling Hereford heifers (n = 24), seronegative for antibodies to BVDV1 and BVDV2 were bred by artificial insemination with X chromosomebearing sperm from an Angus sire. On d 175 of pregnancy, heifers were intranasally inoculated with either Dulbecco’s Modified Eagle Medium + 2% horse serum (sham control) or 4.0 log TCID50 noncytopathic type 2 BVDV to generate control and transient infected calves, respectively. All BVDV-inoculated dams seroconverted by d 14 post-inoculation and all sham-inoculated control dams remained seronegative. Twelve, seronegative control heifer calves were born to the control dams, and 11 seropositive (to type 2 BVDV) TI heifer calves were born to BVDV-inoculated dams. All offspring were raised on pasture until weaning. At weaning, all calves were transported to our feedlot research facility, housed in one group feedlot pen, and transitioned to a high-energy concentrate-based diet until reaching an approximate body weight (BW) of 600 kg. Upon arrival, all animals received a standard heifer growth implant containing 200 mg of testosterone propionate and 20 mg of estradiol benzoate, a modified live viral vaccine containing IBR-BRSV-PI3, and were dewormed. Jugular blood samples were obtained every 28 d until harvest (280 d on feed) and analyzed for biomarkers of inflammation. Data were analyzed as a randomized block design with the MIXED procedures of SAS. There was a treatment x time interaction (P < 0.05) for plasma ceruloplasmin and the oxidized form of glutathione. On d 0 and 28 of the feeding period, all biomarkers were similar across treatments. By d 56 of the feeding period, ceruloplasmin (P < 0.03) and the oxidized form of glutathione (P < 0.01), indicators of chronic inflammation, were increased in plasma samples from TI heifers compared with controls. These parameters remained greater in TI heifers compared with controls throughout the feeding period. There were no treatment or treatment x time interactions for plasma interferon (INF)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and haptoglobin. These data suggest that TI heifers may be experiencing a greater level of oxidative stress later in the finishing period. [ABSTRACT FROM AUTHOR]

Vaccines are known to impact both the immune and reproductive systems. The objective of this research was to identify immunological and cyclic differences following vaccination for Bovine Viral Diarrhea Virus (BVDV) and/or Infectious Bovine Rhinotracheitis (IBR). Brahman cows (n = 15) were administered PGF2α to regress corpus lutea on d -3. Animals (d 0) were immunized (2mL, intramuscular injection) with one of three treatments: 1) Modified Live Vaccine (MLV) for BVDV and IBR (BVD+IBR; n = 5), 2) MLV for BVDV only (BVD; n = 5), or 3) sterile saline (CON; n = 5). Blood samples (30 mL/cow) were collected (d -3, 0, 2, 4, 6, 8, 10, and 14) and peripheral blood mononuclear cells (PBMC) were isolated. PBMC were incubated with propidium iodide and antibodies for specific surface cell markers (CD4, CD8, CD25, CD14, CD86, and CD335). An Amnis FlowSight flow cytometer determined cell type percentage. BVDV and IBR antibody concentrations were analyzed in serum samples (d -3, 0, and 14). Plasma samples (d 0, 2, 4, 6, 8, 10, and 14) were evaluated for interferon (IFN)-γ, interleukin (IL)-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, IL-17A, macrophage inflammatory protein (MIP)-1α, MIP-1β, IL-36RA, interferon-gamma-induced protein (IP)-10, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor (TNF) α, and vascular endothelial growth factor (VEGF) A concentrations by a MagPix multiplex machine using a MILLIPLEX Bovine Cytokine/ Chemokine Magnetic Bead Panel. Progesterone (d 0, 2, 4, 6, 8, 10, and 14) and estradiol (d 0) concentrations were determined by RIA. Differences in antibody titers, PBMC populations, and cytokine concentrations were analyzed as repeated measures using PROC MIXED (SASv9.4). Forty percent of BVD+IBR animals experienced abnormal estrus cycles, but no BVD or CON animals did. There was a treatment effect on BVD titer concentration with BVD animals having greater titer concentrations than CON (P = 0.02) but similar concentrations to BVD+IBR (P = 0.18). There was a treatment by time interaction (P < 0.0001) on IBR titers with BVD+IBR animals having greater titer concentrations on d 14 compared with BVD and CON. Treatment had no effect on leukocyte populations (P ≥ 0.1409), but all populations differed over time (P ≤ 0.0045). Antigen presenting cells (CD14+) and natural killer cells (CD335+) were affected by a treatment and time interaction (P ≤ 0.0479). BVD animals had increased CD14+ cells on d 2, 4, 8, and 14 compared with CON, but CON had a greater CD335+ cell population compared with BVD and BVD+IBR on d 10. There tended to be or was a significant treatment by day interaction for IL-1α (P = 0.08), IL-1b (P = 0.03), IL-10 (P = 0.06), IFN-γ (P = 0.05), IP-10 (P = 0.02), MIP-1α (P = 0.02), MIP-1 b (P = 0.01), TNFα (P = 0.01), and VEGFA (P = 0.03). IL-1a, IL-10, IL-1b, and MIP-1 b increased in BVD+IBR from d 0 to 4 or 6 then decreased but not in CON or BVD. Increased VEGFA was observed in CON compared with BVD and BVD+IBR animals. Overall, BVD+IBR resulted in abnormal cycles and changes in cytokine concentrations and leukocyte populations. USDA is an equal opportunity provider and employer. [ABSTRACT FROM AUTHOR]

Two 89-d experiments (Exp 1 and Exp 2) evaluated the effects of feeding an immunomodulatory feed additive (NutraGen; NG) in calves following exposure to bovine viral diarrhea virus (BVDV) on d -3 and Mannheimia haemolytica (MH) infection on d 0. For each experiment, steers [body weight (BW) = 251 ± 38.2 kg)] were randomly allocated to 1 of 3 treatments. Treatments included a placebo (CON; Exp 1 n = 5; Exp 2 n = 5), a placebo fed from d -18 to d -3 followed by NG fed from d -3 to d 28 (CHLG; Exp 1 n = 5; Exp 2 n = 6), and NG fed from d -18 to d 28 (PREC; Exp 1 n = 6; Exp 2 n = 5). Data were analyzed using the GLIMMIX procedure of SAS Version 9.4 (SAS Institute, Cary, N.C.). Animal served as the experimental unit and time served as a repeated measure. Treatment, time, and the treatment × time interaction served as fixed effects. Block was included as a random effect. Multiple treatment × time interactions and time effects occurred for serum glucose, lactate, blood urea nitrogen, and non-esterified fatty acid concentrations (P ≤ 0.003) in both experiments. There was a general trend for serum glucose to decrease over time postchallenge, suggesting increased cellular utilization of glucose in response to the challenge. In Exp 1, treatment effects occurred for serum glucose (P ≤ 0.001) and serum lactate (P ≤ 0.01), where calves assigned to the CHLG treatment displayed the greatest concentrations of the metabolites. Blood urea nitrogen concentrations peaked at h 48 in Exp 1 and h 6 in Exp 2. There were no treatment effects or treatment × time interactions for serum cortisol, hair cortisol, or fecal corticosterone concentrations in either experiment (P ≥ 0.17). There were, however, multiple time effects for serum cortisol, hair cortisol, and fecal corticosterone concentrations in both experiments (P ≤ 0.02), indicating that the challenge directly impacted cortisol and corticosterone production. Serum cortisol steadily increased from h 96 to h 168 in both experiments. Trends in cortisol and corticosterone production were similar in both experiments; however, peak concentration times for these variables occurred later in Exp 2. These data suggest that feeding NG to calves may alter glucose availability and nutrient utilization in response to infection resulting from a bovine respiratory disease challenge. [ABSTRACT FROM AUTHOR]

Two 89-d experiments (Exp 1 and Exp 2) evaluated the effects of feeding an immunomodulatory feed additive (NutraGen; NG) in calves following exposure to bovine viral diarrhea virus (BVDV) on d -3 and Mannheimia haemolytica (MH) infection on d 0. For each experiment, steers [body weight (BW = 251 ± 38.2 kg were randomly allocated to 1 of 3 treatments. Treatments included a placebo (CON; Exp 1 n = 5; Exp 2 n = 5), a placebo fed from d -18 to d -3 followed by NG fed from d -3 to d 28 (CHLG; Exp 1 n = 5; Exp 2 n = 6), and NG fed from d -18 to d 28 (PREC; Exp 1 n = 6; Exp 2 n = 5). Data were analyzed using the GLIMMIX procedure of SAS Version 9.4 (SAS Institute, Cary, N.C.). Animal served as the experimental unit and time served as a repeated measure. Treatment, time, and the treatment × time interaction served as fixed effects. Block was included as a random effect. Cytokine data were tested for normality using the Shapiro-Wilk test, determined to be non-normal, and logarithm (base 10) transformed as a result prior to statistical analysis. Multiple time effects and treatment × time interactions occurred for serum MH, BVDV 1, and BVDV 2 antibody concentrations in both experiments (P ≤ 0.05). In Exp 1, there was a tendency for an overall treatment effect for calves assigned to the CON treatment to exhibit the greatest MH serum antibody concentrations (P = 0.06). While no differences were detected between treatment groups, BVDV 1 and BVDV 2 antibody concentrations peaked on the same day in both experiments, d 28 post-challenge. There were no treatment × time interactions, treatment effects, or time effects for serum TNF-α, IFN-γ, or IL-17A concentrations (P ≥ 0.13) in either experiment. In Exp 1, there was a treatment effect for serum IL-10 (P ≤ 0.0001), where calves assigned to the PREC treatment had increased serum IL-10 concentrations when compared with calves in the other treatment groups. In Exp 2, there was a tendency for a treatment effect for IL-10 concentrations, where calves assigned to the PREC treatment displayed decreased IL-10 concentrations when compared with calves in the other treatment groups (P = 0.07). These data suggest that feeding NG to calves prior to a stress experience may alter cellular responses. Overall, these experiments suggest that NG impacted antibody concentrations and cytokine expression during a bovine respiratory disease challenge. [ABSTRACT FROM AUTHOR]

This 2-yr study evaluated the effects of winter vs. year-round supplementation of Bos indicus -influenced beef cows on cow reproductive performance and impact on their offspring. On day 0 of each year (approximately day 122 ± 23 of gestation), 82 to 84 mature Brangus cows/yr were stratified by body weight (BW; 475 ± 67 kg) and body condition score (BCS; 4.85 ± 0.73) and randomly assigned to 1 of 6 bahiagrass (Paspalum notatum) pastures (13 to 14 cows/pasture). Treatments were randomly assigned to pastures consisting of winter supplementation with molasses + urea (WMOL), or year-round supplementation with molasses + urea (YMOL) or wheat middling-based range cubes (YCUB). Total yearly supplement DM amount was 272 kg/cow and supplements were formulated to be isocaloric and isonitrogenous (75% TDN and 20% CP). On day 421 (weaning; approximately 260 ± 24 d of age), 33 to 35 steers/yr were vaccinated against parainfluenza-3 (PI3) and bovine viral diarrhea virus type 1 (BVDV - 1) and transported 1,193 km to a feedlot. Steers were penned according to maternal pasture and managed similarly until slaughter. Data were analyzed using the MIXED and GLIMMIX procedures of SAS. On day 217 (start of breeding season), BCS was greater (P = 0.01) for YMOL than WMOL cows, whereas BCS of YCUB did not differ (P ≥ 0.11) to both WMOL and YMOL cows. The percentage of cows that calved, calving date, birth BW, and preweaning BW of the first offspring did not differ (P ≥ 0.22) among maternal treatments. Plasma cortisol concentrations were greater (P ≤ 0.001) for YCUB steers at feedlot arrival (day 422) than WMOL and YMOL steers. Moreover, YCUB steers had greater (P = 0.02) and tended (P = 0.08) to have greater plasma concentrations of haptoglobin compared to WMOL and YMOL steers, respectively. Antibody titers against PI3 and BVDV-1 viruses did not differ (P ≥ 0.25) among maternal treatments. Steer BW at feedlot exit was greater (P ≤ 0.05) for YMOL and WMOL than YCUB steers. However, feedlot DMI did not differ (P ≥ 0.37) by maternal treatment. Hot carcass weight, yield grade, LMA, and marbling did not differ (P ≥ 0.14) among maternal treatments. Percentage of steers that graded low choice was enhanced (P ≤ 0.05) for WMOL and YCUB than YMOL steers. Maternal year-round supplementation of range cubes or molasses + urea either did not impact or decrease growth, immune function, and carcass characteristics of the offspring when compared with maternal supplementation of molasses + urea during winter only. [ABSTRACT FROM AUTHOR]

Aims: Vaccines for bovine ephemeral fever virus (BEFV) are available but are difficult to produce, expensive or suffer from genetic instability. Therefore, we designed constructs encoding C‐terminally truncated forms (transmembrane anchoring region deleted) of glycoproteins G and GNS such that they were secreted from the cell into the media to achieve high‐level antigen expression, correct glycosylation pattern and enable further simple purification with the V5 epitope tag. Methods and Results: In this study, synthetic biology was employed to create membrane‐bound and secreted forms of G and GNS glycoprotein. Mammalian cell culture was employed as an antigen expression platform, and the secreted forms of G and GNS protein were easily purified from media using a highly effective, single‐step method. The V5 epitope tag was genetically fused to the C‐termini of the proteins, enabling detection of the antigen through immunoblotting and immunomicroscopy. Our data demonstrated that the C‐terminally truncated form of the G glycoprotein was efficiently secreted from cells into the cell media. Moreover the immunogenicity was confirmed in mice test. Conclusions: The immuno‐dot blots showed that the truncated G glycoprotein was present in the total cell extract, and was clearly secreted into the media, consistent with the western blotting data and live‐cell images. Our strategy presented the expression of secreted, epitope‐tagged, forms of the BEFV glycoproteins such that appropriately glycosylated forms of BEFV G protein was secreted from the BHK‐21 cells. This indicates that high‐level expression of secreted G glycoprotein is a feasible strategy for large‐scale production of vaccines and improving vaccine efficacy. Significance and Impact of the Study: The antigen expression strategy designed in this study can produce high‐quality recombinant protein and reduce the amount of antigen used in the vaccine. [ABSTRACT FROM AUTHOR]

The objectives of this study were to determine the effect of including soybean co-products on growth performance and respiratory disease incidence in high-risk stocker cattle. For this study, crossbred beef bulls and steers [n = 272; initial body weight (BW) 230.9 ± 19.7 kg] were purchased from local auction markets at 3 time points (load 1: n = 93 cattle; load 2: n = 91 cattle; load 3: n = 88 cattle). On day 0, cattle were processed (ear tagged, vaccinated, dewormed, ear notched for identification of cattle persistently infected with bovine viral diarrhea virus, castrated intact bulls), stratified by BW and allocated randomly to 1 of 8 pens (0.45 ha). Pens were assigned randomly to 1 of 3 dietary treatments: 1) a control supplement containing no soy co-products (CON); 2) a supplement containing soybean meal (SBM); or 3) a supplement containing soy oil (SBO). All supplements were isonitrogenous and isoenergetic. Cattle were fed supplements (2.45 kg DM/day) and offered bermudagrass hay for ad libitum intake for a 42-day trial. Body weights were taken on days 14, 28, 41, and 42 of the trial. Each morning, cattle were observed for signs of morbidity. If presenting with symptoms, cattle were pulled and rectal temperatures were recorded; if temperature exceeded 40°C, calves were treated according to a standard protocol. Cattle were deemed chronic if they received 3 antibiotic treatments and had an overall average daily gain (ADG) of less than 0.5 kg/d. Statistical analyses were performed using SAS 9.4, with PROC MIXED used for BW, ADG, and antibiotic cost analysis. Body weights were analyzed with the repeated measure of day and for treatment, day, and treatment by day interaction. PROC GLIMMIX was used for morbidity and mortality analyses. There was no treatment by day interaction (P = 0.99) or main effect of treatment (P = 0.86), but there was a day effect (P < 0.0001) with BW increasing throughout the trial. Average daily gain was not affected by treatment (P = 0.42; 0.81 kg/d for SBM, 0.79 kg/d for SBO, and 0.76 kg/day for CON). Overall morbidity and mortality were 71% and 1%, respectively, and were not affected by treatment (P = 0.62 and P = 0.99, respectively). Relapse rates and chronics were not affected by treatment (P = 0.52 and P = 0.51, respectively). Total cost of antibiotic treatments was not different (P = 0.8; $30.37 for SBO, $28.95 for CON, and $28.52 for SBM). While the inclusion of soybean co-products did not affect BW, respiratory disease incidence, or cost of antibiotic treatments in high-risk stocker cattle, further work will focus on haptoglobin, hemocytology, and antibody titer responses during the receiving period. [ABSTRACT FROM AUTHOR]

Vaccines are created to help the immune system fight pathogens faster and more effectively, but little is known on how season of the year impacts the immune system response to vaccination. This research was conducted to evaluate how ambient temperature (summer vs fall) impacted antibody production and immune cell type changes in Brahman and Brahmaninfluenced cows. Cows (n = 18) were immunized (2 mL I.M.) with a combination Modified Live Vaccine for Bovine Viral Diarrhea Virus (BVDV) and Infectious Bovine Rhinotracheitis Virus (IBR) on d 0 in either July 2022 (Summer; n = 12) or November 2022 (Fall; n = 6). Blood samples (30 mL/cow) were collected on d -3, 0, 2, 4, 6, 8, 10, 14 post vaccination and transferred to 50 mL conical tubes containing EDTA to separate plasma and peripheral blood mononuclear cells (PBMC). Density gradient centrifugation was used to isolate PBMC. Serum samples were also collected (10 mL/cow) on d -3, 0, 14. Cells were incubated with propidium iodide and antibody surface cell markers for CD4, CD8, CD25, CD14, CD86, and CD335. An Amnis FlowSight flow cytometer was used to determine the percentage of each cell type in the PBMC. Concentrations of antibodies for BVDV and IBR were determined in serum samples collected pre-vaccination (d -3 and 0) and on d 14. Differences in antibody titers and leukocyte populations were analyzed as repeated measures using the MIXED model procedure in SAS. There were no differences in IBR (P = 0.2) or BVDV (P = 0.47) antibody concentrations between seasons. Percentage of antigen presenting cells (CD14+) was greater in the Summer compared with the Fall (P = 0.01; Summer=11.7 ± 1%; Fall = 7.3 ± 1.1%), but natural killer cells (CD335+) were greater in the Fall compared with the Summer (P = 0.002; Summer = 0.6 ± 0.6%; Fall = 4.4±0.7%). There was a significant treatment by time interaction for antigen presenting cells (P = 0.04), T-helper cells (CD4+; P = 0.01), activated T-helper cells (CD4+CD25+; P ≤ 0.0001), activated cytotoxic T-cells (CD8+CD25+; P = 0.03), activated T-cells (CD25+; P ≤ 0.0001), and natural killer cells (P ≤ 0.0001), but there was no difference between seasons in activated antigen presenting cells (CD14+CD86+; P = 0.19). From pre-vaccination to d 14, natural killer cells were elevated during the Fall compared with the Summer on all days (P = 0.04). Antigen presenting cells were greater in the Summer compared with the Fall on d 4, 10 and 14 (P < 0.02). T-helper cells, activated T-helper cells, activated cytotoxic T-cells, and activated T-cells increased post-vaccination in the Fall, but did not change during the Summer. Thus, ambient temperature (summer vs fall) did not directly impact production of antibodies for IBR or BVDV but did induce changes in specific immune cells following vaccination. [ABSTRACT FROM AUTHOR]

The influence of sex and reciprocal cross type were evaluated in Brahman-sired (B × A) and Angussired (A × B) F1 cattle following modified-live viral vaccination regarding virus neutralization titers (VNT) and cell-mediated immune (CMI) responses following in vitro exposure to Bovine Viral Diarrhea Virus (BVDV) Type 1 (BVDV1) and Type 2 (BVDV2) genotypes. VNT against BVDV were based on virus neutralization assay, and CMI responses were measured using the PrimeFlow mRNA assay for determination of the frequency of BVDV and interferon-gamma (IFN-γ) positive cells. Mixed model procedures utilized individual calf ID as a random effect with fixed effects of F1 cross type, calf sex, evaluation date, and potential 2-way interactions; models for frequency of BVDV and IFN-γ positive cells, stimulation conditions (BVDV1, BVDV2, mitogen, none) and potential two-way and three-way interactions of fixed effects. Relationships of immune responses with calf birth weight and weaning weight and steer carcass traits were also investigated. This study found several CMI traits differed due to the type of cross and calf sex; however, no differences in VNT were attributed to these effects. Cells from B × A animals consistently ranked approximately 20% greater for BVDV positive cells (BVDV+) than those from A × B animals pre-MLV vaccination; however, post-MLV vaccination, cells from A × B animals ranked 20% greater (P < 0.05) for CD2+, CD4+, and CD8+ cells. Post-MLV steers consistently had 30 to 35% greater (P < 0.05) frequencies of BVDV+ cells following viral exposure; steers had greater frequencies (P < 0.05) of CD4+ and CD335+ cells expressing IFN-γ and ranked greater for CD2+ and CD8+ cells when compared with heifers in both crosses. Only vaccination timing affected BVDV VNT. No significant correlations involving VNT and CMI responses were observed among A × B animals when stimulated with BVDV1, but among B × A animals, positive correlations were observed with IFN-γ in CD4+ (r = 0.406, P = 0.049) and CD335+ (r = 0.472, P = 0.020). When stimulated with BVDV2, positive correlations of 0.33 to 0.39 (P < 0.05) were observed between BVDV and IFN-γ frequency within cell type; these were not significant when stimulated with BVDV1, except for CD335+ cells (r = 0.41, P = 0.003). No correlations for VNT and CMI responses were observed when stimulated with BVDV2. No major correlations between immune responses and weight or carcass traits were observed, and immune response category for BVDV or IFN-γ frequency did not influence birth weight or weaning weight. Differences in CMI responses involving reciprocal cross types and sex observed in this project may relate to widely reported reciprocal cross differences in birth weight in Bos indicus - Bos taurus crossbred cattle and warrant additional study. [ABSTRACT FROM AUTHOR]

This experiment evaluated humoral responses in beef calves vaccinated against parainfluenza-3 virus (PI3), bovine respiratory syncytial virus (BRSV), and bovine herpesvirus-1 (BHV-1) using serum neutralization (SN) tests or enzyme-linked immunosorbent assays (ELISA). Blood samples were collected from 50 overtly healthy Angus-influenced steers (183 ± 3 kg of body weight, 212 ± 2 d of age) on days 0, 21, 35, and 49 of the experiment. Steers were vaccinated against respiratory viruses on days 0 and 21. Blood was processed for serum collection and frozen in duplicates. One of the duplicates was analyzed for antibodies against BRSV, PI3, and BHV-1 using commercially available ELISA (IDEXX Switzerland AG, Liebefeld-Bern, Switzerland), and results reported as sample:positive control (S/P , %) ratio. The other duplicate was analyzed for antibodies against the same vaccine antigens via SN. This method reports results as titers, the greatest dilution that provides complete protection of the cells, which were transformed with base 2 log for statistical analyses. Samples were classified as positive for the presence of antibodies by SN if log-transformed titer ≥ 2 for all viruses, and by ELISA if S/P ratio ≥ 50% for BHV-1 or ≥ 20% for PI3 and BRSV. Day effects were detected (P < 0.01) for SN and ELISA across all vaccine antigens, as antibody levels increased after vaccine administration. Linear fits were detected (P < 0.01) across all vaccine antigens when regressing the SN and ELISA results; as SN titer increased, the ELISA S/P ratio linearly increased (P < 0.01). Kendall (τ) and Spearman's rank (ρ) correlations were also detected (P < 0.01) between SN and ELISA results across all vaccine antigens. The SN and ELISA were very strongly correlated (ρ ≥ 0.83) for BHV-1 and PI3 and strongly correlated (ρ = 0.66) for BRSV. Cohen's kappa coefficient for diagnosis agreement between methods was strong for BHV-1 and PI3 (κ ≥ 0.88), but weak (κ = 0.47) for BRSV. The sensitivity of the ELISA in yielding true positive results approached 100% across all antigens. The specificity of the ELISA in yielding negative results was satisfactory for BHV-1 and PI3 assays (84.0% and 88.5%, respectively) but not for BRSV (34.4%). Despite limitations in detecting true BRSV negatives, results from this experiment indicate that the commercial ELISAs tested herein can be used as surrogate for SN tests in quantifying humoral responses to vaccination against BHV-1, PI3, and BRSV in beef cattle. [ABSTRACT FROM AUTHOR]

The objectives of this study were to determine the effects of oral supplementation with Saccharomyces cerevisiae fermentation products (SCFP ; SmartCare and NutriTek; Diamond V, Cedar Rapids, IA) on immune function and bovine respiratory syncytial virus (BRSV) infection in preweaned dairy calves. Twenty-four Holstein × Angus, 1- to 2-d-old calves (38.46 ± 0.91 kg initial body weight [ BW ]) were assigned two treatment groups: control or SCFP treated, milk replacer with 1 g/d SCFP (SmartCare) and calf starter top-dressed with 5 g/d SCFP (NutriTek). The study consisted of one 31-d period. On days 19 to 21 of the supplementation period, calves were challenged via aerosol inoculation with BRSV strain 375. Calves were monitored twice daily for clinical signs, including rectal temperature, cough, nasal and ocular discharge, respiration effort, and lung auscultation. Calves were euthanized on day 10 postinfection (days 29 to 31 of the supplementation period) to evaluate gross lung pathology and pathogen load. Supplementation with SCFP did not affect BW (P = 0.762) or average daily gain (P = 0.750), percentages of circulating white blood cells (P < 0.05), phagocytic (P = 0.427 for neutrophils and P = 0.460 for monocytes) or respiratory burst (P = 0.119 for neutrophils and P = 0.414 for monocytes) activity by circulating leukocytes either before or following BRSV infection, or serum cortisol concentrations (P = 0.321) after BRSV infection. Calves receiving SCFP had reduced clinical disease scores compared with control calves (P = 0.030), reduced airway neutrophil recruitment (P < 0.002), reduced lung pathology (P = 0.031), and a reduced incidence of secondary bacterial infection. Calves receiving SCFP shed reduced virus compared with control calves (P = 0.049) and tended toward lower viral loads in the lungs (P = 0.051). Immune cells from the peripheral blood of SCFP-treated calves produced increased (P < 0.05) quantities of interleukin (IL)-6 and tumor necrosis factor-alpha in response to toll-like receptor stimulation, while cells from the bronchoalveolar lavage (BAL) of SCFP-treated calves secreted less (P < 0.05) proinflammatory cytokines in response to the same stimuli. Treatment with SCFP had no effect on virus-specific T cell responses in the blood but resulted in reduced (P = 0.045) virus-specific IL-17 secretion by T cells in the BAL. Supplementing with SCFP modulates both systemic and mucosal immune responses and may improve the outcome of an acute respiratory viral infection in preweaned dairy calves. [ABSTRACT FROM AUTHOR]

Social behavior is an important driver of infection dynamics, though identifying the social interactions that foster infectious disease transmission is challenging. Here we examine how social behavior impacts disease transmission in Indo-Pacific bottlenose dolphins (Tursiops aduncus) using an easily identifiable skin disease and social network data. We analyzed tattoo skin disease (TSD) lesions based on photographs collected as part of a 34-year longitudinal study in relation to the sociality of T. aduncus using three metrics (degree, time spent socializing, and time in groups) and network structure, using the k -test. We show that calves with TSD in the second year of life associated more with TSD-positive individuals in the first year of life compared with calves that did not have TSD. Additionally, the network k -test showed that the social network links are epidemiologically relevant for transmission. However, degree, time spent in groups, and time spent socializing were not significantly different between infected and uninfected groups. Our findings indicate that association with infected individuals is predictive of an individual's risk for TSD and that the social association network can serve as a proxy for studying the epidemiology of skin diseases in bottlenose dolphins. [ABSTRACT FROM AUTHOR]

This study utilized 204 Angus-based beef steers (249 ± 23 kg SD) from a single ranch with initial serum α-tocopherol concentrations of 3.9 ± 1.0 mg/L to determine the effect of varying doses of vitamin E (VE) on feedlot performance, antibody response to vaccination, and antioxidant defense. Seven days after arrival, steers were blocked by body weight and weaning protocol (preweaned, unweaned heavy, and unweaned light) and randomly assigned to pens within blocks (12 pens per block). Preweaned steers had been weaned for approximately 35 d prior to arrival, and unweaned steers were weaned when leaving the origin ranch. Pens within block were randomly assigned to supplemental VE (ROVIMIX E-50 Adsorbate, DSM Nutritional Products, Heerlen, The Netherlands) treatments (n = 9 pens per treatment): no supplemental VE (CON), 25 IU/kg dry matter (DM ; LOW), 500 IU per steer daily (MED), or 1,000 IU per steer daily (HIGH). Back-calculated supplemental VE intake was 0, 151 (24.8 IU/kg DM), 484, and 995 IU/d for CON, LOW, MED, and HIGH, respectively. On day 6, all steers received a booster vaccine against bovine viral diarrhea virus (BVDV ; Bovi-Shield Gold, One Shot, Zoetis, Parsippany, NJ). Steers were weighed on day −1, 0, 14, 26, and 27. One steer per pen representative of the average body weight of the pen was chosen as a sampling animal for blood (day −1, 6, 14, 26, and 28) and liver (day −3 and 24). Data were analyzed as a randomized complete block design using Proc Mixed of SAS with pen as the experimental unit and the fixed effects of treatment and block. Linear, quadratic, and cubic contrast statements were constructed using Proc IML; morbidity data were analyzed using Proc Glimmix. Day 24 liver and day 26 serum α-tocopherol concentrations were linearly increased by supplemental VE (P < 0.01). Supplemental VE did not affect DM intake, average daily gain, or gain:feed from day 0 to 27 (P ≥ 0.37), or the percentage of steers treated for respiratory disease (P ≥ 0.44). Day 24 liver glutathione concentrations decreased linearly due to supplemental VE (P ≤ 0.02). Total- and Mn-superoxide dismutase activities were quadratically affected by supplemental VE (P ≤ 0.07), with MED steers exhibiting the greatest activity. Over time, BVDV type 1 and 2 antibody titers numerically decreased, whereas the decrease in BVDV type 1 titers was lesser for HIGH steers (linear P = 0.04). Increasing doses of VE improved VE status but did not affect overall receiving period performance in steers with minimal to adequate VE status upon arrival. [ABSTRACT FROM AUTHOR]

Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue that affects performance; however, little information is available pertaining to its effects on immunity. Recently, it has been shown that supplemental CP can improve performance in weaned steers postvaccination. Thus, the objective of this study was to evaluate the effect of supplemental CP on innate and adaptive immune responses in stocker steers chronically exposed to ergovaline. Angus steers (n = 12 pens; 3 steers/pen) were stratified by weight and assigned to a 2 × 2 factorial arrangement to examine crude protein levels of supplement (14% or 18%) and ergovaline exposure (0 or 185 μg ergovaline/kg BW/d via ground endophyte-free (EF) or endophyte-infected (EI) tall fescue seed, respectively) on immune response. Consumption of low to moderate concentration of ergovaline from EI tall fescue seed was sufficient to induce mild symptoms associated with fescue toxicosis. Blood samples were collected at day 0, 42, and 56 to evaluate infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea virus (BVDV) type 1b titers following vaccine challenge. Additionally, serum cytokine concentrations were evaluated using Quantibody Bovine Cytokine Arrays on day 0, 28, and 42. Data were analyzed using PROC MIXED of SAS with repeated measures. Regardless of treatment, no differences were observed in IBR and BVDV-1b seroconversion following vaccine challenge (P > 0.05). Regardless of crude protein concentration, EI steers had greater concentrations of proinflammatory cytokines (TNF-α, IFN-γ, IL-1α), chemokines (CCL2, CCL4, MIG), anti-inflammatory cytokines (IL-2, -13, -15, -21), and various growth factors (FGF-1, IGF-1, VEGF-A) when compared to EF steers (P < 0.05). Furthermore, VEGF-A and IGF-1 concentrations were greater in EI-14 steers on day 28 compared to EI-18, EF-14, and EF-18 steers (P < 0.05), however, this difference was not observed on day 0 or 42 (P > 0.05). Based on these data, steers exposed to ergovaline have an increase in pro- and anti-inflammatory cytokines and supplemental CP had minimal impact to mitigate this response. However, in the current study, exposure to ergovaline had little to no effect on adaptive immunity and response to vaccination. Together, chronic exposure to ergovaline results in a hyperactive innate immune response, which may lead to an immuno-compromised animal. [ABSTRACT FROM AUTHOR]

Genetic selection is an inexpensive and complementary strategy to traditional methods of improving animal health and welfare. Nonetheless, endeavors to incorporate animal health and welfare traits in international breeding programs have been hampered by the availability of informative phenotypes. The recent eradication program for bovine viral diarrhea (BVD) in the Republic of Ireland has provided an opportunity to quantify the potential benefits that genetic selection could offer BVD eradication programs elsewhere, as well as inform possible eradication programs for other diseases in the Republic of Ireland. Using a dataset of 188,085 Irish calves, the estimated direct and maternal heritability estimates for the birth of persistently infected calves following likely in utero exposure to BVD virus ranged from not different from zero (linear model) to 0.29 (SE = 0.075; threshold model) and from essentially zero (linear model) to 0.04 (SE = 0.033; threshold model), respectively. The corresponding genetic SD for the direct and maternal effect of the binary trait (0, 1) ranged from 0.005 (linear model) to 0.56 (threshold model) units and ranged from 0.00008 (linear model) to 0.20 (threshold model) units, respectively. The coefficient of direct genetic variation based on the linear model was 2.56% indicating considerable genetic variation could be exploited. Based on results from the linear model in the present study, there is the potential to reduce the incidence of persistent infection in cattle by on average 0.11 percentage units per year which is cumulative and permanent. Therefore, genetic selection can contribute to reducing the incidence of persistent infection in cattle. Moreover, where populations are free from persistent infection, inclusion of the estimated genetic merit for BVD in national breeding indexes could contribute to a preservation of a BVD-free status. Results from the present study can be used to inform breeding programs of the potential genetic gains achievable. Moreover, the approaches used in the present study can be applied to other diseases when data become available. [ABSTRACT FROM AUTHOR]

Rapidly rehydrating newly received feedlot cattle may reduce disease risks caused by the marketing and transportation-related restrictions on feed and water. The significant loss of water and key nutrients from the body can put the animal at increased risk for bovine respiratory disease (BRD). It is hypothesized that rapidly rehydrating calves upon arrival may reduce disease risks by facilitating an easier transition to the feedlot and limiting loss in value due to illness and decreased performance. The objective of this study was to rapidly replenish water and key nutrients in newly received feedlot calves by assessing water intake (WI) and providing a supplemental water source or a nutritional rehydration solution during the first three days after arrival. Crossbred heifers [n= 270; initial BW = 232 ± 16 kg] were individually weighed after 11 h transportation and sorted into 18 pens (6 pens/treatment). Treatments were: 1) Control (CON): standard in-pen automatic water source (Richie CM480; one waterer/pen); 2) Supplemental water source (SWS): CON + one additional stock tank/pen; and 3) Nutritional rehydration solution (NRS): trace-mineral based drinking solution provided with one stock tank/pen. Treatments were provided from days 1 to 4, after which supplemental tanks were removed. From days 5 to 56, cattle only had access to CON (automatic waterer). Water intake was measured daily throughout the trial, BW and whole blood (5 heifers/pen) were collected on days 1, 4, 14, 28, and 56. Treatment × experimental period interactions (P = 0.03) were observed for WI, dry matter intake (DMI), average daily gain (ADG). The DMI was greater for both SWS and NRS than CON from days 5 to 15 (P = 0.01), and SWS had greater DMI than CON from days 16 to 29 (P = 0.01). Both SWS and NRS had greater WI than CON from days 1 to 4 (P = 0.001), but not from days 5 to 56 (P = 0.36). The ADG was less for NRS than CON from days 1 to 4 (P = 0.01); however, treatments did not affect ADG from days 5 to 56 (P = 0.12). No treatment or treatment × day or experimental period effects (P = 0.061) were observed for BW and gain:feed (G:F). Treatments did not affect morbidity and mortality (P = 0.20). No treatment effect or treatment × day interactions were observed for plasma glucose, non-esterified fatty acids, total red or white blood cell counts (P ≥ 0.23). Hematocrit and hemoglobin decreased for SWS and NRS when compared with CON (P ≤0.05). Bovine viral diarrhea virus (BVDV) antibodies increased for NRS when compared with SWS and CON (P = 0.004). The results suggest that providing SWS or NRS to newly received calves during the initial three days after arrival increases WI, DMI, antibodies against respiratory viruses, hydration, but has little impact on performance, blood metabolites, and immune cells. [ABSTRACT FROM AUTHOR]

Genome editing in the genetic stocks of food animals has tremendous potential as a tool for genetic improvement best suited to introduce traits not readily available for intensive selection in commercial breeding populations, especially those affecting disease resistance and adaptation to climate. To date, gene-editing has been used to alter prolactin receptor and produce heat-tolerant, registered Angus for commercial production of semen and embryos that rapidly improves efficient quality beef production in the tropics. More recently, genome alterations based on rationale design have been tested to demonstrate host resistance to porcine reproductive and respiratory syndrome virus and bovine viral diarrhea virus in swine and cattle, respectively. This presentation will highlight the results of these new traits to breed healthier commercial animals that will eventually change global market dynamics of livestock production. [ABSTRACT FROM AUTHOR]

A 2 × 2 factorial design study evaluated the impact of pre- vs. post-weaning vaccination and different post-weaning frequency of energy supplementation (daily vs. 3X weekly) on growth and immunity of beef calves. At 14 d before weaning (d -14), 48 Angus calves (24 steers and 24 heifers; 244 ± 33 kg; 196 ± 20 d) were stratified by BW and age, and randomly assigned to receive vaccinations against bovine viral diarrhea virus 1a (BVDV-1a) and parainfluenza-3 (PI-3) on d -14 and 0 (PRE) or 7 and 21 (POS), relative to weaning. Calves were weaned on d 0 and offered daily concentrate DM supplementation (50:50 soybean hulls and corn gluten feed; 71% TDN, 15% CP of DM) at 0.5% of BW for 7 d. On d 7, calves were stratified by vaccination scheme and assigned into 1 of 16 drylot pens (3 calves of same sex/pen; 4 pens/treatment). Pens were randomly assigned to receive similar weekly concentrate DM supplementation (1% of BW multiplied by 7 d) that was divided and offered daily (7X) or three times weekly (3X; Mondays, Wednesdays, and Fridays) from d 7 to 43. From d 0 to 43, calves were provided ad libitum ground tall fescue hay (57% TDN, 13% CP of DM). Blood samples were collected from jugular vein on d 0, 1, 3, 7, and 14, relative to the respective first vaccination, and on d 43 of the study. Effects of timing of vaccination × frequency of supplementation were not detected for any variable in this study (P ≥ 0.12), except for overall ADG from d -14 to 43 (P = 0.04), which was less for PRE-3X vs. PRE-7X, POS-3X, and POS-7X calves (0.60, 0.70, 0.70, and 0.77 ± 0.04 kg/d, respectively; P ≤ 0.08). Post-weaning total DMI and G:F did not differ among treatments (P ≥ 0.11). Pre-weaning vaccination increased plasma concentrations of cortisol and haptoglobin from d 0 to 3, relative to first vaccination (P ≤ 0.03), and decreased serum PI-3 titers on d 43 compared with post-weaning vaccination (P < 0.0001). Decreasing the supplementation frequency tended (P = 0.10) to increase overall plasma cortisol concentrations and reduce overall serum BVDV-1a titers. Hence, pre-weaning vaccination associated with reduced post-weaning frequency of energy supplementation caused the greatest reduction on calf growth performance. Post-weaning vaccination and daily energy supplementation alleviated inflammation and improved humoral immunity compared with pre-weaning vaccination and reduced post-weaning frequency of energy supplementation of recently weaned beef calves. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhea virus (BVDV) is a major viral pathogen affecting the cattle industry. Control of BVDV occurs through preventative vaccination or elimination of persistently infected animals. However, evaluation of the longevity of cows vaccinated during pregnancy has not been conducted. In experiment 1, heifers born in 2014 (n = 32) were randomly assigned to receive a modified-live viral vaccination (MLV; Bovishield Gold 5 FP) at 3 months of age, and subsequently receive a MLV or killed viral vaccination (KV; Cattlemaster Gold 5 FP) against BVDV beginning at weaning for the duration of their lifespan in the herd. Heifers born in 2015 (n = 29) were randomly assigned to receive a MLV or KV beginning at 3 months of age for the duration of their lifespan in the herd. Heifers were bled for analysis of antibody titers throughout their first year of life, and twice-yearly beginning at 2 years of age. Titers for infectious bovine rhinotracheitis (IBR) and BVDV, herd longevity, and reproductive performance were collected. Vaccination type did not influence IBR titer (P ≥ 0.18), herd longevity (P ≥ 0.86), or reproductive development (P ≥ 0.19). Cows born in 2015 and their calves were used in experiment 2 (n = 24) to evaluate responses in the preweaning period. Cow and calf samples of blood and ruminal contents, and colostrum and milk were collected at d 1, 7, 35, 63, and 205 of age. Cows receiving KV vaccinations have ~60% more colostral IgG than cows receiving MLV vaccination (P = 0.02). Experiment 3 observed postweaning feed efficiency and ruminal fermentation of calves from experiment 2. Cow vaccine treatment did not affect average daily gain, gain:feed, ruminal fermentation, or metabolites (P > 0.05). An immune challenge was conducted in experiment 4. Calves (n = 8) were early-weaned and inoculated with BVDV Type 2a strain 1373. Samples were collected over 28 days to evaluate blood counts, virus isolation, and metabolites. A tendency for increased clinical scores, including mucosal discharge, and temperatures were observed for calves born to MLV cows (P = 0.08). Calves born to KV cows had increased leukocyte and lymphocyte concentrations compared to MLV calves (P = 0.03). Overall, blood metabolites (glucose, non-esterified fatty acids, and blood urea nitrogen) were unaffected by treatment (P ≥ 0.8), however, metabolites did differ by day post-challenge (P = 0.01). Metabolites were altered by the viral challenge and indicate the nutritional status of the animal shifted to support immune responses. Vaccination treatment had little influence on the calf's ability to mount an immune response. These four studies indicate that both KV and MLV vaccination programs can be used to protect against BVDV without negatively impacting cow longevity, calf growth performance, and calf immunocompetence. [ABSTRACT FROM AUTHOR]

RNArecombination is amajor driving force for the evolution of RNAviruses and is significantly implicated in the adaptation of viruses tonewhosts, changesof virulence, aswell as intheemergenceofnewviruses includingdrug-resistant andescapemutants. However, the molecular details of recombination in animal RNA viruses are only poorly understood. In order to determine whether viral RNA recombination depends on translation of viral proteins, a nonreplicative recombination system was established which is based on cotransfection of cells with synthetic bovine viral diarrhea virus (family Flaviviridae) RNAgenome fragments either lacking the internal ribosome entry site required for cap-independent translation or lacking almost the complete polyprotein coding region. The emergence of a number of recombinant viruses demonstrated that IRES-mediated translation of viral proteins is dispensable for efficient recombination and suggests that RNA recombination can occur in the absence of viral proteins. Analyses of 58 independently emerged viruses led to the detection of recombinant genomes with duplications, deletions and insertions in the 5' terminal region of the open reading frame, leading to enlarged core fusion proteins detectable by Western blot analysis. This demonstrates a remarkable flexibility of the pestivirus core protein. Further experiments with capped and uncapped genome fragments containing a luciferase gene for monitoring the level of protein translation revealed that even a ~1,000-fold enhancement of translation of viral proteins did not increase the frequency of RNA recombination. Taken together, this study highlights that nonreplicative RNA recombination does not require translation of viral proteins. [ABSTRACT FROM AUTHOR]

Impairment of bovine reproductive function and decreased pregnancy rates have been reported in modified-live vaccinated females. The objective of this study was to determine if virus could be found in various areas of the bovine reproductive tract following vaccination. Previously vaccinated beef females (n = 50) were administered a single dose of one of three treatments on d0 of the estrous cycle; BoviShield (n = 20), Titanium 5 (n = 20), or ViraShield (n = 10) based on estrus expression. Blood samples were collected on d0, 15, and 30 to evaluate Infectious Bovine-Rhinotracheitis (IBR) and Bovine Viral Diarrhea Virus (BVDV) titers and progesterone concentrations. On d15/16, half the animals from each treatment were non-surgically flushed with sterile saline (Uterine Fluid), and uterine biopsies (Uterine Tissue) were collected. On d17, follicular fluid and granulosa cells were collected by follicle aspirations. Remaining animals had uteri flushed and uterine tissue collected on d29, and follicles aspirated on d31. All samples were evaluated for presence of virus. Data were analyzed using the MIXED procedure of SAS. Sub-luteal progesterone concentrations were observed in 15% of the BoviShield and Titanium treatments on d15 and d30, versus 0% in the ViraShield treatment. Virus isolation and RT-PCR results were negative in all samples for all animals. Titers for BVDV-1 did not differ between treatments (P = 0.99) or treatment by time (P = 0.48). Titers for IBR tended to differ by treatment (P = 0.09) and treatment by time (P = 0.06), while BVDV-2 titers were affected by treatment (P < 0.01) and treatment x time (P < 0.01). Sub-luteal progesterone animals had a rapid rise in IBR and BVDV-2 titers from d0 to d15 and then tended (P < 0.07) to decrease to d30, compared to animals that had normal cycles where titers increased from d0 to d15 and remained elevated on d30. Collectively, these results indicate an alternative mechanism of impacting reproductive efficiency, possibly through an immune response. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhea virus (BVDV) infects cattle and may lead to persistent infection (PI). The PI animals harbor BVDV throughout their life and become immune tolerant against BVDV. Thus, diagnosis of this virus in herd is highly important. Recombinant E2 protein expression (using pET-32a inEscherichia coli) was confirmed by SDS-PAGE and Western blotting; then purified by Ni+affinity chromatography. Chickens were immunized with BVDV-E2 protein, and IgY antibodies were extracted from egg yolk by PEG-6000. The peak titer of anti-BVDV-E2-IgY was 1:128,000 after the fifth immunization. IgY-based enzyme-linked immuno sorbent assay (ELISA) and immunochromatographic assay (ICA) were further developed. Coincidence of ELISA and ICA test with RT-PCR was 95.45 and 90.91%, respectively. The anti-BVDV-E2 IgY could be used in routine screening of BVDV infection. Besides, it can also be applicable while licensing and/or using live vaccines; screening of imported products containing bovine serum and strong surveillance of BVDV outbreaks. Preparation of Chicken IgY against BVDV recombinant E2 protein for developing ELISA and ICA for BVDV detection. [ABSTRACT FROM AUTHOR]

Bovine respiratory disease (BRD) is the most common and economically detrimental disease of beef cattle during the postweaning period, causing the majority of morbidity and mortality in feedlots. The pathogenesis of this disease often includes an initial viral infection, which can predispose cattle to a secondary bacterial infection. The objective of this experiment was to determine the effects of timing of an intratracheal Mannheimia haemolytica (MH) challenge relative to 72 h of natural exposure to bovine viral diarrhea virus (BVDV) type 1b persistently infected (PI) calves on performance, serum antibody production, total and differential white blood cell (WBC) count, rectal temperature, clinical severity score (CS), and haptoglobin (Hp). Steers (n = 24; 276 ± 31 kg initial BW) were randomly allocated to 1 of 3 treatments (8 steers/treatment) in a randomized complete block design. Treatments were steers not exposed to calves PI with BVDV 1b and not challenged with MH (CON), steers intratracheally challenged with MH 84 h after being exposed to calves PI with BVDV 1b for 72 h (LateCh), and steers intratracheally challenged with MH 12 h after being exposed to calves PI with BVDV 1b for 72 h (EarlyCh). Performance (ADG, DMI, and G:F) was decreased (P < 0.001) for both EarlyCh and LateCh from d 0 to 4. From d 5 to 17, LateCh appeared to compensate for this lost performance and demonstrated increased ADG (P = 0.01) and G:F (P = 0.01) compared with EarlyCh. Both EarlyCh and LateCh had decreased platelet counts (P < 0.001) compared with CON. Antibody concentrations of BVDV and MH were higher (P < 0.05) for both EarlyCh and LateCh compared with CON. Rectal temperature, CS, and Hp increased (P < 0.001) across time from h 4 to 48, h 4 to 36, and h 8 to 168, respectively. Within 24 h of MH challenge, WBC and neutrophil concentrations within the blood increased whereas lymphocyte concentrations decreased. The timing of BVDV exposure relative to a MH challenge appears to influence the CS and acute phase response associated with BRD. As typical beef cattle marketing channels allow for variation in the timing of respiratory pathogen exposure, understanding the physiological changes in morbid cattle will lead to improved management of BRD. [ABSTRACT FROM AUTHOR]

Our objective was to examine immunosuppression induced by dexamethasone (DEX) administration in cattle on immunological responses to a multivalent respiratory vaccine containing replicating and nonreplicating agents. Steers (n = 32; 209 ± 8 kg) seronegative to infectious bovine rhinotracheitis virus (IBRV), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), and parainfluenza-3 virus (PI3V) were stratified by BW and randomly assigned to 1 of 3 treatments: 1) acute immunosuppression (ACU; 0.5 mg/kg BW DEX intravenously at 1000 h only on d 0), 2) chronic immunosuppression (CHR; 0.5 mg/kg BW DEX intravenously at 1000 h on d -3 to 0), or 3) a control (CON; no DEX). On d -4, steers were fitted with intravenous catheters in the jugular vein and placed into individual stanchions. At 1200 h on d 0, steers were administered a respiratory vaccine containing modified-live virus (MLV) isolates of IBRV, BVDV, BRSV, and PI3V and a Mannheimia haemolytica (MH) toxoid. On d 4, cattle were transported (177 km) and housed in an isolated outdoor pen. Serum was harvested on d 0, 7, 14, 21, 28, 35, 42, and 56 to determine IBRV-, BVDV-, BRSV-, and PI3Vspecific antibody titers and MH whole cell and leukotoxin antibody concentrations. Sera from d -2, 0, 1, 3, 7, and 14 were used to quantify haptoglobin (Hp) concentration and ceruloplasmin (Cp) activity. Nasal swab specimens were collected on d 0, 3, and 14 to determine the presence of IBRV, BVDV, BRSV, and PI3V via PCR analysis. There was a treatment x day interaction (P < 0.01) such that CHR steers had a greater (P ≤ 0.07) BVDV antibody titer on d 14, 21, and 28. Moreover, IBRV-specific antibodies increased beginning on d 14 for CHR and on d 28 for ACU and remained greater through d 56 compared with CON (P ≤ 0.03). Conversely, serum MH whole cell antibody concentration was least (P ≤ 0.06) for CHR from d 7 to 28 and greatest for CON (P ≤ 0.04) on d 56. Treatment altered Hp such that CON exhibited a greater (P < 0.01) Hp concentration than CHR but was not different from ACU (P = 0.16). On d 3, Cp was greatest for CON, intermediate for ACU, and least for CHR (treatment x day; P ≤ 0.01). The prevalence of IBRV and BVDV in nasal swabs on d 14 was 67 and 56%, respectively, for CHR; 10 and 10%, respectively, for CON; and 9 and 0%, respectively, for ACU (P ≤ 0.006). Results suggest that CHR allowed increased replication of MLV vaccine agents. Conversely, DEX-induced immunosuppression blunted the acute phase protein and antibody response against the nonreplicating MH toxoid. [ABSTRACT FROM AUTHOR]

Research has indicated that trace mineral (TM) supplementation may alter immune function and reduce morbidity associated with bovine respiratory disease. The objective of this experiment was to determine the influence of dietary Cu, Mn, and Zn supplementation on the performance, clinical signs, and TM balance of calves following a bovine viral diarrhea virus (BVDV) and Mannheimia haemolytica (MH) combination respiratory pathogen challenge. Steers (n = 16; 225 ± 20 kg BW) from a single ranch were processed, weaned, and randomly pairwise assigned to either the TM-supplemented (MIN) or the control (CON) experimental treatments. The MIN calves received an additional 150 mg of Cu, 130 mg of Mn, and 320 mg of Zn daily and the CON calves received the basal diet with no additional Cu, Mn, or Zn supplementation. The basal diet contained sufficient Mn and Zn but inadequate Cu based on published nutrient requirements. After 46 d on the experimental treatments, all calves were naturally exposed to a heifer persistently infected with BVDV type 1b for 4 d and then subsequently intratracheally challenged with MH. Data were analyzed using the GLIMMIX procedure of SAS with sampling time serving as a repeated measure and calf serving as the experimental unit. The respiratory challenge was validated via increased BVDV type 1b antibody concentrations, MH whole cell and leukotoxin antibody concentrations, rectal temperatures (TEMP), and subjective clinical severity scores (CS). Calf performance (P = 0.48) was not affected by TM supplementation. Mineral supplementation also did not impact the CS or TEMP of calves (P = 0.53). There was a treatment time (P < 0.001) interaction observed for liver Cu concentrations. The concentrations of Cu, Mn, Zn, and Fe within the liver; Cu, Mn, and Zn within the muscle; and Cu, Zn, and Fe within the serum were all impacted by time (P = 0.03). Calves receiving the MIN treatment had greater (P < 0.01) liver Cu and Mn concentrations compared with CON calves. In contrast, serum Cu and Fe concentrations were increased (P = 0.05) in CON calves compared with MIN calves. Mineral supplementation did not impact TM concentrations within the muscle (P = 0.38). The supplementation of Cu, Mn, and Zn can improve the Cu and Mn status within the liver and serum of calves in response to a BVDV and MH challenge. When Cu is supplemented to calves receiving a marginally Cu-deficient diet, Cu status within the body is significantly improved. [ABSTRACT FROM AUTHOR]

Bovine respiratory disease (BRD) affects millions of cattle in the US annually. This study sought to identify commensal pathogens in animals without clinical signs that were predictive of clinical BRD using the Wisconsin Health Scoring (WHS) system. Cases were healthy cattle that were later diagnosed with BRD (WHS = 5.0), positive controls (PC) were cattle that were diagnosed with BRD at the time of initial sampling and negative controls (NC) were those that remained healthy throughout the study (WHS = 4.0). Beef feedlot cattle were sampled in Colorado (CO; cases = 13, NC = 500, PC = 488) and Washington (WA; cases = 5, NC = 499, PC = 506). Preweaned Holstein dairy calves were sampled from California (CA; cases = 73, NC = 1017, PC = 1003) and New Mexico (NM; cases = 25, NC = 381, PC = 376). For each animal, mid-nasal and deep pharyngeal swabs were used to test for nine BRD pathogens. ANOVA testing (P< 0.05) and odds ratios (OR) were calculated for each population. In CO, bovine viral diarrhea virus (P = 0.0001, OR = 13.1) and Histophilus somni (P = 0.008, OR = 4.2) were predictive of cattle that would be diagnosed with BRD while bovine respiratory syncytial virus (BRSV; P = 1.1 × 10-6, OR = 40.8) was most predictive in WA. In NM, BRSV (P = 0.005, OR = 5.8) was also predictive of clinical BRD. No pathogen was predictive of BRD risk in CA. Prevalence of the predictive pathogen was higher (P < 0.05) in cases than in PC cattle suggesting that the incidence of pathogens taken at the time of BRD diagnosis may not reflect the pathogen initiating disease. These results also highlight geographical differences in the incidence of BRD pathogens which should be considered when managing to reduce disease. [ABSTRACT FROM AUTHOR]

Vaccination is the most effective way at preventing bovine viral diarrhea virus (BVDV) infection. Maternal antibodies from colostrum provide immunoglobulins to stimulate the naïve immune system of calves, but these wane within the first 3 months of life. Limited information is available on the quality of colostrum influenced by vaccines, and their subsequent calf protection against BVDV. The objective of this study was to evaluate calf performance against BVDV after consumption of colostrum from cows vaccinated with either a killed viral (KV, n = 7) or modifiedlive viral vaccination (MLV, n = 9) against BVDV. Calves were weaned at approximately 140 days of age and intranasally challenged with BVDV strain 1373. Clinical scores were evaluated twice daily for 28 days, and blood samples were collected on day -2, 0, 3, 6, 8, 10, 14, and 28 post-infection (dpi) for evaluation of complete blood counts, virus isolation, and metabolites. Colostrum IgG was similar between treatment groups (P = 0.75). Calves that were born to KV cows had increased leukocyte and lymphocyte concentrations compared to MLV calves (P = 0.03). Calves born to MLV cows tended to have higher clinical scores, including higher temperatures, and nasal discharge (P = 0.08). Overall, metabolites were unaffected by treatment (P = 0.8), however, metabolites did differ by dpi. Serum urea nitrogen was lowest at dpi 8 (P = 0.02) and glucose was reduced from dpi -2 through d 14 (P < 0.001). Non-esterified fatty acids were elevated through dpi 14 (P < 0.0001) and haptoglobin peaked on dpi 10 (P < 0.0001). Metabolites were altered by the viral challenge and indicate the nutritional status of the animal was shifted to support the immune response. Overall, vaccination treatment of the cow had little impact on the calf's ability to mount an immune response. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhea virus (BVDV) is a critical disease negatively impacting many facets of the cattle production system. Cattle infected with the persistent (PI) form of BVDV are the primary reservoirs and source of transmission and may be implicated with an increased risk of bovine respiratory disease (BRD) to exposed calves in feedlots. To date, little to no data exists regarding characterization of the effects PI-BVDV has on the bovine nasal microbiome, an important feature for bovine health. To investigate these effects, Angus-crossbred beef calves were selected and randomly assigned to either continuous exposure (E, n = 3) or non-exposure (NE, n = 3) to an auction market sourced PI-BVDV positive (PI, n = 1) calf from weaning to 112 days post-weaning. Nasal swab samples were collected upon weaning, 56 days post-weaning, and 112 days post-weaning. Next generation sequencing was used to measure the effects of PI-BVDV on the nasal microbiome. Alpha diversity, including Shannon Index and Observed OTUs, and beta diversity, including Bray-Curtis and Jaccard distances, were not different (P > 0.05) between treatments. Next, community structure was assessed at the amplicon sequence variant (ASV) level and LEfSe was used to identify the bacterial biomarkers for each treatment. Results indicated that ASV5-Mycoplasma could be a biomarker for the PI and E treatments due to its high relative abundance in each when compared with the NE treatment. Overall, ASV5-Mycoplasma was identified as a potential biomarker for the prediction and diagnosis of persistently infected bovine viral diarrhea virus among both calves infected with and exposed to the virus and may be an additional biomarker for the increased risk of bovine respiratory disease in exposed feedlot cattle. [ABSTRACT FROM AUTHOR]

Two experiments (EXP1 and EXP2) evaluated the effects of NutraGen (NG) on calf health following exposure to bovine viral diarrhea virus (BVDV) on d -3 and Mannheimia haemolytica (Mh) infection on d 0. For each EXP, steers (BW = 251 ± 38.2 kg) were randomly allocated to 1 of 3 treatments (TRT). Treatments included a placebo (CON; EXP1 n = 5; EXP2 n = 5), a placebo fed from d -18 to d -3 followed by NG fed from d -3 to d 28 (CHLG; EXP1 n = 5; EXP2 n = 6), and NG fed from d -18 to d 28 (PREC; EXP1 n = 6; EXP2 n = 5). There was no treatment by time interaction (TRT×TME) or TRT effect for rectal temperatures (RT) or clinical scores (CS) in EXP1 or CS in EXP2 (P = 0.26). There was a TRT×TME for respiration rates (RR) during the first 24 h following Mh infection (P = 0.04), and a tendency for a TRT effect from d -3 to d 14, and overall in EXP1 (P ≥ 0.10). There was a tendency for a TRT×TME for RT from d -3 to d 14 in EXP2 (P = 0.04). There was a TRT effect for RR from d -3 to d 14 and overall in EXP2 (P ≥ 0.05). There was a TRT×TME for leukocytes during the first 24 h following Mh infection in EXP1 (P = 0.03) and overall in both EXP (P ≥ 0.001). There was no TRT×TME or TRT effect for neutrophils (NEU), lymphocytes (LYM), or NEU:LYM in EXP1 (P = 0.19); however, there were multiple TRT×TME and TRT effects for NEU, LYM, and NEU:LYM in EXP2 (P ≥ 0.05). These experiments suggest that NG has the potential to alter clinical and cellular responses during a bovine respiratory disease challenge. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate whether prenatal transportation stress (PNS) affects the immune response of Brahman calves after vaccination against Bovine Viral Diarrhea Virus (BVDV). Mature Brahman cows inseminated to a single Brahman sire in 2018 were assigned to either Control (n=35; not transported) or PNS (n=37; 2h of transportation at 60, 80, 100, 120, and 140±5 d of gestation). Of the calves born in 2019, 11 Control and 12 PNS calves were studied for vaccine treatment (VAX). Temperament score, body weight, and blood samples were obtained from calves prior to weaning (D-28), prior to first BoviShield vaccine (D+35), and after second BoviShield vaccine (D+98). Serum cortisol was determined by RIA. Humoral immune response was evaluated by virus neutralization (VN) assays using serum collected at respective timepoints post-vaccination. Cell-mediated immune (CMI) response was evaluated using a novel PrimeFlow RNA assay that incorporates cell surface marker staining with intracellular RNA expression of cytokines on blood samples obtained at D+35 and D+98. Data were analyzed using GLM procedures of SAS. Only total WBC and absolute lymphocytes were increased with PNS (P< 0.05), while lymphocytes were also decreased with VAX (P< 0.05). There was no PNS effect on the VN or CMI results, serum cortisol concentration, or temperament score. VAX tended (P=0.06) to reduce serum cortisol, as well as resulted in an increase in VN titers (P< 0.01) and frequency of interferon-γ mRNA expression in the CD4+ population (P< 0.01), but not in CD25+ population (P=0.26). Interaction between sampling day and VAX resulted in more drastic increase (P< 0.05) from D+35 to D+98 in VN titers, CD4+ population frequency of interferon-γ mRNA expression, and CD25+ population mean fluorescent intensity. Vaccine treatment positively affected humoral and cell-mediated immune responses; however prenatal transportation stress did not negatively impact response of Brahman calves to immunization against BVDV. [ABSTRACT FROM AUTHOR]

Aims The aim of the study was the development of cross-priming amplification for ubiquitous detection of bovine viral diarrhoea virus ( BVDV) species 1 and 2. Methods and Results Three and five specific primers, respectively, for the detection of BVDV-1 and BVDV-2, were designed on the basis of the sequences of the 5′ UTR region. Incubation temperature and reaction time were determined. The optimal incubation conditions using water bath were 63°C for 75 min. Reverse transcription step ( RT) was not required. The results were visualized under UV-light as a bright yellow fluorescence in positive samples. Additional method for results interpretation was agarose gel electrophoresis. Positive samples showed the presence of ladder-like banding patterns, formed by harpin-like cross-priming amplification ( CPA) products. Sensitivity of CPA was compared with conventional RT- PCR and real-time RT- PCR. The CPA detection limit was 3500 copies for BVDV-1 and 80000 copies for BVDV-2 per reaction. For RT- PCR it was 350 and 80 copies for BVDV-1 and BVDV-2, respectively, and for real-time RT- PCR it was 35 copies for BVDV-1 and 80 copies for BVDV-2. The sensitivity of the developed method is sufficient to detect persistently infected ( PI) animals. Positive results were found in 24 of 25 BVDV isolates belonging to species 1 and 2. Additionally, one false-negative result for BVDV-2 was detected. There were no false-positive results in negative samples and in the negative control. Both sets of primers used for the detection of BVDV-1 and BVDV-2 were not able to detect atypical pestiviruses. CPA positive results were confirmed by RT- PCR and real-time RT- PCR. Conclusions CPA is a rapid method for the detection of BVDV-1 and BVDV-2 in field samples from PI animals. Significance and Impact of Study This is the first report on the application of the CPA method for the detection of BVDV. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate intake, metabolic, inflammatory, and acute-phase responses in beef heifers vaccinated against pathogens that cause bovine respiratory disease (BRD). Eighteen weaned Angus heifers (initial BW 257 ± 3 kg; initial age 245 ± 2 d) were ranked by BW and allocated to 2 groups, which were assigned to 2 experiments of 7 d and the following treatments on d 1 of each experiment: 1) revaccinated against infectious bovine rhinotracheitis virus, parainfluenza-3 virus, bovine respiratory syncytial virus, bovine viral diarrhea Types 1 and 2 viruses, and Mannheimia haemolytica (VAC; 2 mL [s.c.]) and 2) receiving a 2-mL s.c. injection of 0.9% sterile saline (CON). The group receiving VAC in Exp. 1 was assigned to CON in Exp. 2 and vice versa. Heifers were weaned 21 d before Exp. 1, when they all received the first dose of the aforementioned vaccine. Heifers were maintained in individual pens and offered free-choice mixed alfalfa-grass hay and 3.5 kg/d (DM basis) of a corn-based supplement throughout the study. During Exp. 1, hay and concentrate intake were evaluated daily. During Exp. 2, blood samples were collected before (-2 and 0 h) and at 2, 4, 6, 8, 12, 16, 24, 36, 48, 60, 72, 96, 120, 144, and 168 h after treatment administration. In Exp. 1, treatment ? day interactions were detected (P < 0.01) for forage intake and total DMI; these parameters were reduced (P = 0.05) in VAC heifers compared with CON heifers on d 1 and 2 by an average of 1.7 and 0.8 kg (DM basis), respectively. In Exp. 2, mean serum tumor necrosis factor a (TNFa) concentration was greater (P = 0.05) in VAC heifers compared with CON heifers and treatment ? hour interactions were detected for all plasma variables (P = 0.02), whereas a similar tendency was detected (P = 0.09) for blood TNFa mRNA expression. Haptoglobin concentrations were greater (P = 0.05) in VAC heifers compared with CON heifers from 16 to 120 h. Blood TNFa mRNA expression was greater (P = 0.05) in VAC heifers compared with CON heifers at 12 h. Cortisol concentrations were greater (P = 0.05) in VAC heifers compared with CON heifers from 2 to 16 h. Insulin concentration was greater (P = 0.02) in VAC heifers compared with CON heifers at 2 h. Leptin concentrations were greater (P = 0.05) in VAC heifers compared with CON heifers from 6 to 16 h. In conclusion, vaccinating beef heifers against BRD pathogens decreased forage intake and total DMI during the 2 d following vaccination in Exp. 1, which can be associated with transient metabolic, inflammatory, and acute-phase responses elicited by vaccination in Exp. 2. [ABSTRACT FROM AUTHOR]

The Oklahoma Quality Beef Network utilizes three health protocols for producer choice based on vaccine timing and viral components. The study objective was to examine the effects of vaccine type and timing on animal performance, and immune response pre-and post-weaning. A total of 151 Angus, Angus x Hereford, or Angus x Charolais calves were randomly assigned to one of three health protocols stratified by breed of sire, sex, and date of birth. Vaccination treatments were 1) KV/MLV – multivalent inactivated BRD vaccine (KV) administered on d 0 and revaccination with a pentavalent modified-live virus on d 125; 2) MLV/MLV – pentavalent modified-live virus on d 0 and d 125; or 3) WEAN – pentavalent modified-live virus on d 125 and 139. Virus-specific antibody (Ab) titer data was determined using serum-neutralization from serum collected at six time points. Antibody titers, BW, and ADG variables were evaluated following vaccination. Results indicated there was no treatment effect on BW. Bovine viral diarrhea virus (BVD) also displayed significance for treatment x date interaction. The MLV/MLV provided greatest response from d 0 (branding) to d 125 (weaning) than the other two treatments. There was no difference between the KV/MLV group and the WEAN group from d 0 to d 125. By d 167 the KV/MLV group had a greater immune response than the MLV/MLV and WEAN groups. The MLV/MLV provided the greatest protection from branding to weaning. Providing a KV at branding had minimal effect on BVD titers but responded well to MLV vaccine at weaning by d 167. The WEAN group generated the least number of titers overall. Further investigation is needed to determine the long-term protection of vaccination strategies. [ABSTRACT FROM AUTHOR]

There are concerns about antagonisms between immunity and animal productivity in livestock production. The objective of this study was to evalu-ate the effect of antibody levels through a response to vaccination protocol, weaning timing, and their interac-tion on performance and carcass quality traits in Angus beef cattle. Final antibody level and response to vac-cination were based on neutralizing serum antibodies against bovine viral diarrhea virus type 2 (BVDV2). Calves were followed through development and the feedlot phase, with collection of yearling ultrasound (,n = 957), preharvest (n = 762), and carcass (n = 673) data. In this study, 48% of the animals were observed to have positively responded to the vaccine, as evidenced by higher final antibody levels compared to prevacci-nation antibody levels. Increased final antibody levels were significantly (P < 0.05) associated with increased yearling weight and increased subcutaneous fat over the rump. An interaction between final antibody level and weaning time also was associated (P < 0.05) with Warner-Bratzler shear force (WBSF) and meat pH, with a favorable, negative relationship between final anti-body and WBSF in calves weaned at initial vaccination. Overall antibody response by wean time interaction had a significant (P < 0.05) association with ADG and meat pH, with calves weaned at initial vaccination having a favorable, positive relationship between overall anti-body response and ADG. Under both the final antibody and overall antibody response models, animals weaned at initial vaccination had significantly (P < 0.05) lower intramuscular fat at yearling time and conversely higher harvest weight than animals weaned at the booster vac-cination. When antibody response was grouped (none, low, high), a significant interaction (P < 0.05) between antibody response group and weaning time was iden-tified for ADG, harvest weight, and HCW. Animals weaned at the initial vaccination in the high antibody response group had the advantage for ADG, harvest weight, and HCW compared to animals in the high-response group that were weaned at booster vaccination. Linear increases in antibody response generally did not have negative effects on performance or carcass quality traits in finished cattle (P > 0.05). Therefore, producers should not be concerned about decreased production or quality attributes as a result of developing a robust anti-body response to vaccination for BVDV2 in beef cattle. [ABSTRACT FROM AUTHOR]

Vaccination against viruses has been shown to help prevent bovine respiratory disease in cattle. However, both passively acquired maternal antibody concentration and calf age have been shown to impact the ability of the immune system of a calf to respond to vaccination. The objectives of this study were to identify and evaluate environmental and management factors that affect 1 ) passively acquired bovine viral diarrhea virus (BVDV) type 2 antibody level, 2) decay rate of passively acquired BVDV type 2 antibody level, and 3) responses to BVDV type 2 vaccinations. A 2-shot modified live vaccine was administered to 1,004 Angus calves that were weaned at either the initial vaccination (n = 508) or the booster vaccination (n = 496). Calves weaned at the initial vaccination averaged 139 d whereas calves weaned at booster vaccination averaged 128 d of age. Bovine viral diarrhea vims type 2 antibodies were measured in 3 approximately 21-d intervals, serially collected serum samples to quantify antibody levels at initiation and end of vaccination protocol in addition to responses to initial, booster, and overall vaccination protocol. Amount of passively transferred antibody in the calf increased as dam age increased from 2 to 6 yr (P < 0.05) with no differences after dams reached 6 yr (P > 0.05). Calf age nested within birth year-season and dam age affected both initial and final antibody level, initial response, booster response, and overall antibody response to vaccination. The level of circulating, passively acquired maternal antibodies present at the time of vaccination had a significant (P < 0.05) negative effect on antibody responses to vaccination (initial response, booster response, and overall response). Calves that were weaned at the time of initial vaccination had significantly (P < 0.05) greater final antibody level, initial response, and overall response to vaccination than animals weaned at booster vaccination. In order for a calf to mount an overall antibody response to vaccination, maternal antibodies in circulation need to be less than 3.12 titers. However, the age at which a calf reached this antibody threshold was dependent on dam age. This information will help cattle managers and consultants design vaccination protocols to successfully mount an antibody response to vaccination. [ABSTRACT FROM AUTHOR]

Exposure to animals persistently infected (PI) with bovine viral diarrhea virus (BVDV) results in immunomodulation in cohorts. It is hypothesized that the extent of modulation differs for low-risk, precondi-tioned (PC) vs. high-risk, auction market (AM) beef cat-tle. Our objective was to compare immune responses of PC or AM calves in the presence (PI) or absence (CON) of a PI-BVDV pen mate. Crossbred PC steers (n = 27) from a single ranch origin were weaned, dewormed, vaccinated against respiratory and clostridial pathogens, tested for PI-BVDV, and kept on the ranch for 61 d. Subsequently, PC steers were transported to a receiv-ing unit (RU), weighed, stratified by d -1 BW, and assigned randomly to treatment (PCPI or PCCON) with no additional processing. Simultaneously, crossbred AM calves (n = 27) were assembled from regional auction markets and transported to the RU. The AM calves were weighed, stratified by gender and d -- 1 BW, processed under the same regimen used for PC steers at their origin ranch, except bull calves were castrated, then assigned randomly to treatment (AMPI or AMCON). Treatment pens were arranged spatially so that PI did not have fence line contact with CON. Blood samples were col-lected on d 0, 1, 3, 7, and 14 to determine serum con-centrations of haptoglobin (Hp), tumor necrosis factor-a (TNF-a), interferon-y (IFN-y), IL-4, and IL-6. Rectal temperature (RT) was recorded concurrent with blood sampling. In AM calves, RT and Hp increased (man-agement effect; P < 0.001) sharply on d 1; however, exposure to a PI-BVDV pen mate did not affect either variable (P > 0.79) during the 14-d evaluation period. Serum concentrations of TNF-a tended to increase (P = 0.09) for the PI cohort. A treatment x day interaction (P < 0.05) was observed for IFN-y on d 7 and 14 and IL-6 on d 14; these indices were greatest for AMPI. Results indicate weaning management and PI-BVDV exposure alter the immune status of newly received beef cattle. These main effects may be additive because proinflam-matory cytokine concentrations were greatest for AMPI. Therefore, results further indicate that potential health or growth consequences in cohorts exposed to a PI-BVDV pen mate are impacted by previous management and health history. [ABSTRACT FROM AUTHOR]

Exposure to animals persistently infected (PI) with bovine viral diarrhea virus (BVDV) results in immunomodulation of cohorts that may have health and growth consequences; however, effects may differ in low-risk, preconditioned (PC) vs. high-risk, auction market (AM) beef cattle. Our objective was to compare health and performance of PC or AM management systems with (PI) or without (CON) presence of a PI-BVDV pen mate using a 2 × 2 factorial arrangement. Four shipment blocks of crossbred PC steers (n = 236) from 3 ranch-origins were weaned, dewormed, vaccinated, tested for PI-BVDV, and kept on the ranch for ≥42 d. Subsequently, PC steers were transported to a stocker receiving unit (RU), weighed (251 ±2 kg), blood sampled, stratified by d -1 BW, and assigned randomly to treatment (PCPI or PCCON) with no additional processing. Simultaneously, 4 blocks of crossbred AM calves (n = 292) were assembled from regional auction markets and transported to the RU ± 36 h from PC arrival. The AM calves were weighed (245 ± 1.3 kg), stratified by gender and d -1 BW, processed under the same regimen used for PC steers at their origin ranch except bull calves were castrated, and then assigned randomly to treatment (AMPI or AMCON). Treatment pens (0.45 ha) were arranged spatially such that PI did not have fence-line or water source contact with CON. Calves were fed identically and followed the same antibiotic treatment protocol. Daily BW gain for the entire 42-d receiving trial was greater (P < 0.001) for PC (1.2 kg) compared with AM (0.85 kg). There was an exposure effect (P = 0.002) on ADG from d 28 to 42; CON gained 1.12 kg vs. 0.90 kg BW for PI cohort. Morbidity was markedly greater (P < 0.001) in AM (70%) vs. PC (7%), resulting in (P < 0.001) an antibiotic treatment cost of $20.52 and $2.48/animal, respectively. Treatment with a third antibiotic occurred more often (P = 0.04) for PI cohort, and the percentage of chronically ill cattle was greatest (P = 0.06) for AMPI. Upon arrival, BVDV type la, lb, and 2a titers were greater for PC (treatment × day, P < 0.001), and the percentage seropositive to BVDV type la on d 0 was 100% for PC vs. 23% in AM. Platelets increased transiently (P < 0.001) with greater platelets observed in AM (P < 0.001). Results indicate that PC calves gain faster and require fewer antibiotic treatments during the receiving period. Exposure to PI reduced BW gain from d 28 to 42, increased the number of calves treated thrice, and increased chronically ill cattle for AM. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to investigate the effects of injectable trace minerals on humoral responses of calves receiving a viral vaccination. Beef steer calves (n = 99; average BW = 316 ± 4.2 kg), seronegative for bovine herpesvirus-1 (BHV-1) and bovine viral diarrhea virus, genotypes 1 and 2 (BVDV-1 and BVDV-2), were sourced from 2 locations. All calves, except 15 non-vaccinated (sentinel) calves, received a single dose of a multivalent modified live vaccine (Titanium 5; AgriLabs, St. Joseph, MO) containing BHV-1, BVDV-1, BVDV-2, bovine parainfluenza virus type 3, and bovine respiratory syncytial virus. Among the vaccinated calves, 2 treatments were concurrently and randomly applied on the basis of initial serum Se status and BW, including 1) injectable trace mineral supplement (ITM; n = 42; 7 mL subcutaneous.; MultiMin, Fort Collins, CO) containing 15, 40, 10, and 5 mg/mL of Cu, Zn, Mn (all as disodium EDTA salts), and Se (as Na selenite) or 2) saline-injected control (Control; n = 42). As a measure of humoral immunity, neutralizing antibody titers were measured on d 0, 14, 30, 60, and 90, relative to vaccine administration. All calves were seronegative for each of the 3 viruses on d 0, and sentinel calves remained seronegative throughout the study. Serum mineral concentrations were evaluated on d 0 and 14. No differences (JP ≥ 0.30) in serum Cu, Zn, Mn, or Se were observed between treatments on d 0. Control steers experienced a decrease (P < 0.001) in serum Zn and Se, and ITM steers had an increase (P = 0.007) in serum Cu on d 14 relative to initial d 0 values. On d 14, serum Zn and Se concentrations were greater (P < 0.01) in ITM compared with Control steers. Vaccinated calves experienced marked increases in neutralizing antibody titers by d 30 following vaccine administration. Calves receiving ITM at the time of vaccination experienced greater (P ≤ 0.003) neutralizing antibody titers to BHV-1 on d 14, 30, and 60 compared with Control. These results demonstrate that the injectable trace mineral formulation evaluated in this study, administered concurrently to viral vaccination, does not impair humoral immune responses in beef calves. Further, concurrent administration of ITM and BHV-1 vaccine may enhance the production of neutralizing antibodies to BHV-1 in previously naïve beef calves. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhea virus (BVDV) is a pestivirus that is enzootic in most cattle populations throughout the world. This virus is present throughout the body of persistently infected (PT) cattle. Previous research has not assessed the cooking temperature at which BVDV in meat from PT cattle can be inactivated. Therefore, muscle tissue from 6 PI cattle was harvested, refrigerated, frozen, and heated to various internal temperatures. The concentration of virus present was determined by virus isolation. Average cell culture infective doses (50% endpoint; CCID50) of BVDV per gram of frozen, uncooked meat from PI cattle were 105.85 CCID50/g of whole cuts and 106.02 CCID50/g of ground meat. The virus in whole and ground meat was consistently inactivated when cooked to temperatures greater than or equal to 75°C. A second objective of this research was to thoroughly reassess if Vero cells were permissive to BVDV infection in our laboratory to provide further indication of whether primates, including humans, might be susceptible to BVDV. Vero cells were not permissive to infection with any of 43 different strains of BVDV that readily replicated in Madin Darby bovine kidney cells. In conclusion, this bovine pathogen, which is not considered to be a human pathogen, can be inactivated by cooking ground or whole cuts of meat to 75°C or higher. Care should be taken to ensure that susceptible hosts such as pigs are not fed improperly cooked meat, meat by-products, or waste food originating from PI cattle. [ABSTRACT FROM AUTHOR]

Remote rumen temperature monitoring is a potential method for early disease detection in beef cattle. This experiment was conducted to determine if remotely monitored rumen temperature boluses could detect a temperature change in steers exposed to bovine viral diarrhea virus (BVDV) and challenged with a common bovine respiratory disease pathogen, Mannheimia haemolytica (MH). Twenty-four Angus crossbred steers (BW = 313 ± 31 kg) were allotted to 1 of 4 treatments: 1) no challenge (control); 2) challenge by a 72-h exposure to 2 steers persistently infected with BVDV; 3) bacterial challenge with MH; and 4) viral challenge by a 72-h exposure to 2 steers persistently infected with BVDV followed by bacterial challenge with MH (BVDV + MH). Remotely monitored rumen temperature boluses programmed to transmit temperature every minute were placed in the rumen before the time of exposure to steers persistently infected with BVDV. Rectal temperatures were taken before MH challenge (0) and at 2, 4, 6, 12, 18, 24, 36, 48, 72, and 96 h after MH challenge. Rumen temperatures were recorded 3 d before (-72 h; period of BVDV exposure) through 14 d after (336 h) MH challenge. Rumen temperatures were analyzed as a randomized complete block design with a 2 x 2 factorial arrangement of treatments and a first-order autoregressive covariance structure for repeated measures. A treatment x day interaction was observed for average daily rumen temperature (P < 0.01). A treatment difference (P < 0.01) was observed on d 0, when MH-challenged steers had greater rumen temperatures than steers not challenged with MH. There was no BVDV x day interaction (P > 0.01). Rumen temperatures averaged every 2 h resulted in a BVDV x hour interaction (P < 0.01) and an MH x hour interaction (P < 0.01). The BVDV x hour differences occurred at h -18 to -14, 40 to 46, 110, 122, and 144 to 146 (P < 0.01). The MH x hour difference occurred at h 4 to 24 (P < 0.01). Maximum rumen temperature was increased (P < 0.01) for BVDV (0.8°C), MH (1.2°C), and BVDV + MH (1.3°C) compared with the control. On average, rumen temperatures measured by the boluses at the same time points as the rectal temperatures were 0.13°C less than rectal temperatures, and the 2 body temperatures were highly correlated (r = 0.89). Rumen temperature boluses appear to have potential as a tool for detecting temperature changes associated with adverse health events such as exposure to bovine respiratory disease and BVDV. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify loci linked with bovine respiratory disease (BRD) and subsequently to determine if these same loci were associated with bovine viral diarrhea virus persistent infection (BVD-PI) in affected calves or their dams. A genome-wide linkage study using 312 microsatellites was conducted to identify loci linked with BRD in a Brahman × Hereford sire half-sib family. Disease incidence was recorded from birth to slaughter by daily monitoring. Linkage was suggestive for a QTL on BTA2 (F = 7.31, P = 0.007) and BTA26 (F = 10.46, P = 0.001). Six and 7 markers were added and genotyped between 110 and 126 cM on BTA2 and between 42 and 72 cM on BTA26, respectively, in the intervals where linkage was found. These markers were used to reevaluate the Brahman × Hereford family and to evaluate 3 additional crossbred half-sib families. Linkage was found with BRD on BTA2 (F = 4.94, P < 0.01), with a peak at 110 cM, and on BTA26 (F = 4.03, P < 0.05), with peaks at 42 and 52 cM. The same markers were then tested for an association with BVD-PI in 1) BVD-PI calves compared with age-matched unaffected calves from the same herd or 2) dams with BVD-PI compared with age-matched unaffected calves. Sixty commercial beef cow-calf herds were tested for BVD-PI, and 79 calves from 8 ranches had BVD-PI. Four of 6 markers were associated (P 4.8 × 10-9 to P = 0.01) with BVD-PI on BTA2, and 4 of 7 markers were associated (P = 0.008 to P = 0.04) with BVD-PI on BTA26 when BVD-PI calves were compared with unaffected calves. The comparison of BVD-PI dams with unaffected calves detected associations with BVD-PI for all markers tested on BTA2 (P = 3 × 10-9 to P = 0.005) and for 3 of 7 markers on BTA26 (P = 1.4 × 10-6 to P = 0.006). [ABSTRACT FROM AUTHOR]

The objective was to determine effects of an intratracheal Mannheimia haemolytica challenge after 72–h exposure to bovine viral diarrhea virus type lb (BVDV1b) persistently infected (PT) calves on serum antibody production, white blood cell count (WBC), cytokine concentrations, and blood gases in feedlot steers. Twenty–four steers (initial BW = 314 ± 31 kg) were randomly allocated to 1 of 4 treatments (6 steers/treatment) arranged as a 2 x 2 factorial. Treatments were 1) steers not exposed to steers P1 with BVDV nor challenged with M. haemolytica (control; CON); 2) steers exposed to 2 steers PT with BVDV for 72 h (BVD); 3) steers intratracheally challenged with M. haemolytica (MH); and 4) steers exposed to 2 steers PT with BVDV for 72 h and challenged with M. haemolytica (BVD+MH). There were 12 h between exposure to PT steers and challenge with M. haemolytica. Rectal temperature was increased (P < 0.001) for MH and BVD+MH during the initial 24 h after the M. haemolytica challenge. For MH and BVD+MH, total WBC count was increased (P < 0.01) at 36 h post M. haemolytica challenge compared with CON, whereas in BVD steers, WBC count was decreased (P < 0.01). Total lymphocyte count was increased (P = 0.004) during the initial 72 h post BVDV exposure for the BVD and BVD+MH groups compared with MH and CON, and this difference remained at 96 h post M. haemolytica challenge. An increased (P < 0.001) total neutrophil count was observed during the initial 36 h for the MH group and at 72 h for the BVD+MH challenge group. Interleukin 113, TL–6, and tumor necrosis factor ci (TNFα) concentrations were greater (P ◀ 0.04) in BVD steers than steers not exposed to BVDV, and interferon &#x03B3, IL–1β, and TNFci were greater (P ⩽ 0.02) in MH steers than in steers not challenged with M. haemolytica. There were BVD x MH interactions (P ⩽ 0.04) for plasma carbon dioxide, carbonic acid, and sodium bicarbonate concentrations. Challenge with M. haerrtolytica decreased carbon dioxide, carbonic acid, and sodium bicarbonate concentrations to a greater extent when steers were not exposed to PT steers compared with steers exposed to BVDV. We conclude that the challenge model was successful at inducing bovine respiratory disease (BRD) associated with BVDV and M. haemolytica. Understanding the physiological changes in morbid animals will lead to improved strategies for decreasing severity and economic losses associated with BRD. [ABSTRACT FROM AUTHOR]

A single experiment with a completely randomized design was conducted to evaluate the effects of long- or short-term exposure to a calf identified as persistently infected with bovine viral diarrhea virus (PI-BVD) on feedlot performance and carcass characteristics of freshly weaned, transport-stressed beef heifers. Two hundred eighty-eight heifers that had been vaccinated for BVD before weaning and transport were processed and given a metaphylactic antibiotic treatment at arrival and were fed common receiving, growing, and finishing diets for a 215-d period. Treatments were designed to directly or adjacently expose the cattle to a PI-BVD heifer. Directly exposed treatments were 1) negative control with no PI-BVD calf exposure (control), 2) PI-BVD calf commingled in the pen for 60 h and then removed (short-term exposure), and 3) PI-BVD calf commingled in the pen for the duration of the study (long-term exposure); and spatially exposed treatments were 1) negative control with no PI-BVD calf exposure (adjacent pen control), 2) PI-BVD calf commingled in the adjacent pen for 60 h and then removed (adjacent pen short-term exposure), and 3) PI-BVD calf commingled in the adjacent pen for the duration of the study (adjacent pen long-term expo- sure). Exposure to a PI calf transiently (60 h) or for the duration of the feeding period (215 d) did not affect (P ≥ 0.25) final BW compared with heifers that were not exposed. Neither period nor overall DM1 was affected (P ≥ 0.37) by PI-BVD calf exposure, and no differences (P ≥ 0.44) were observed between short- and long-term exposed heifers in the direct or spatially exposed groups. Likewise, total trial AIDG was not affected (P ≥ 0.36) and overall efficiency of gain (P ≥ 0.19) was unaffected by PI-BVD calf exposure in the direct or spatially exposed groups. The results from this study suggest that exposing previously vaccinated, freshly weaned, transport-stressed beef calves to a calf that is persistently infected with bovine viral diarrhea virus has little, if any, marked effects on health, performance, or carcass characteristics. [ABSTRACT FROM AUTHOR]

Twenty-five years passed between the discovery of the parent strain (WC3) of the pentavalent human-bovine reassortant rotavirus vaccine (PRV) in 1981 and the licensure of PRV in 2006. This orally administered liquid vaccine, which is given as a 3-dose series, is indicated for the prevention of rotavirus gastroenteritis, caused by the G serotypes contained in the vaccine, in infants and children. PRV is recommended by the Advisory Committee on Immunization Practices and the American Academy of Pediatrics for administration to all infants in the United States. These recommendations are supported by the results of the phase III studies, which demonstrated that PRV is well tolerated and efficacious. PRV reduced rotavirusrelated hospitalizations by 96% and was not associated with an increased incidence of serious adverse events, including intussusception. This report focuses on the safety and efficacy data from the late-phase studies of PRV and discusses plans for providing this vaccine to the developing world. [ABSTRACT FROM AUTHOR]

Citrus pulp is a source of flavonoids which have been found to have antioxidant properties. Thus, the objective of this experiment was to investigate the effects of feeding dried citrus pulp on performance of newly received calves. Crossbred beef heifers (n = 254, initial body weight = 248 ± 5.9 kg) were obtained on 3 dates (block, 8 pens/block). Treatments were: 1) a corn and distillers' grains based receiving supplement (control) or 2) a receiving supplement that contained 20% dried citrus pulp (replacing a portion of the corn). Upon arrival from regional livestock markets, cattle had access to hay and water and rested overnight then were processed the next day in which they received an identification tag, were vaccinated with a clostridial and a 5-way modified live bovine respiratory viral, dewormed, weighed, branded, and ear notched for detection of persistent infection with bovine viral diarrhea virus. Each truckload was assigned randomly to pens resulting in 8 pens with 9 to 12 heifers/pen. Pens were assigned randomly to 1 of the 2 treatments. Cattle were offered bermudagrass hay and water for ad libitum intake and were offered up to 1.8 kg/day of their appropriate receiving supplement. Overall average daily gain for the 42-day receiving period was increased (P < 0.01) for calves fed the supplement that included dried citrus pulp (1.01 kg/day) compared to the calves fed the control supplement (0.90 kg/day). However, the percentage of calves treated for clinical bovine respiratory disease was increased (P < 0.05) for calves fed the citrus pulp containing supplement (14% morbidity) compared to control calves (7% morbidity). The supplementation of dried citrus pulp to calves improved growth performance, but did not reduce the incidence of clinical bovine respiratory disease during the receiving period; however, clinical morbidity was low for both treatments. [ABSTRACT FROM AUTHOR]

Trace mineral (TM) supplementation is critical for optimal performance and health. The objective was to determine the effects of varying levels of TM supplementation on feedlot cattle TM status and antibody concentrations. Angus steers (n = 240; BW = 291 kg ± 27.4) were stratified by arrival BW and source and assigned to 1 of 4 treatments (12 pens/treatment; 5 steers/pen). Treatments included a negative control (CON) in which cattle received no TM supplementation, a requirement treatment (1X) in which cattle received added TM at 2016 Nutrient Requirements of Beef Cattle required levels, a 2 times requirements (2X), and a 4 times requirements (4X) treatment. Selenium was included at 0.1, 0.2, and 0.3 mg/kg for 1X, 2X, and 4X respectively. Treatments were chosen based on reported TM supplementation levels from the 2015 Feedlot Consulting Nutritionist Survey. One steer was chosen at random from each pen to be evaluated for serum and liver TM status and antibody concentrations to respiratory viruses. There was treatment × day interaction for serum Co, and liver Cu and Se (P < 0.0001). Serum Co was greatest for the 4X treatment from d 28 through harvest. Liver Cu was greatest for the 2X and 4X treatments from d 56 through harvest. Liver Se was greatest for 2X and 4X from d 28 through harvest. There was an effect of day on liver Co, Fe, Mn, Mo, and Zn (P < 0.0001) and serum Cu, Mn, Mo, Se, and Zn (P < 0.0019). Concentrations for individual TM had different trends over time, however, all reported values were within normal ranges. Serum Zn was greater at harvest (P = .02). There was an effect of time on Bovine Viral Diarrhea Virus Type 1A, Bovine Herpesvirus Type 1, Bovine Parainfluenza 3 virus antibody titer concentrations (P < 0.0001). [ABSTRACT FROM AUTHOR]