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Liver abscesses pose a significant economic burden on the beef industry, resulting in substantial profit losses. A contributor to these losses is the decreased productivity and feed efficiency observed in affected cattle. Reduced feed efficiency could be attributed to the impairment of metabolic activity due to liver tissue damage caused by the abscesses. While tissue within the abscess itself is dysfunctional, little is known about the functional state of the surrounding liver tissue. Considering this, the present research aimed to evaluate liver tissue gene expression profiles at varying distances from liver abscesses. Tissue samples (n = 21) were collected from three distinct regions: 1) <4 mm proximal from the abscess without including abscessed tissue (adjacent tissue), 2) 3 cm proximal from the abscess (nearby tissue), and 3) from livers with no abscesses (healthy controls). Gene expression comparisons utilizing DESeq were conducted between each tissue sample group. The number of differentially expressed genes (FDR ≤ 0.10) identified in each comparison is presented in Table 1. Tissue directly adjacent to the liver abscess was substantially different in gene expression when compared with both the healthy and tissue 3 cm proximal to an abscess. Fewer genes exhibited differential expression between healthy tissue and tissue taken 3 cm away. Gene enrichment analysis was conducted using the KOBAS-i software to identify biological pathways associated with the differentially expressed genes. Genes upregulated in liver tissue adjacent to the abscess were associated (FDR ≤ 0.10) with immune response pathways, including the “T cell receptor signaling pathway” and “Cytokine-Cytokine receptor interaction,” whereas downregulated genes were linked to metabolic pathways such as “Fatty Acid Metabolism” and multiple amino acid biosynthesis pathways. Gene expression differences between tissue 3 cm away and healthy tissue were minimal; however, enrichment analysis identified significant (FDR ≤ 0.10) metabolic pathways such as the “peroxisome proliferator-activated receptor signaling” which is involved in gluconeogenesis and lipid metabolism, suggesting some metabolic alterations up to 3 cm proximal from the abscess. Upregulation of immune response pathways and downregulation of metabolic pathways in the adjacent tissue suggest a shift in cellular priorities, diverting resources to combat the active infection rather than routine metabolic processes. This localized immune response and metabolic dysregulation observed in the liver tissue adjacent to the abscess, coupled with metabolic alterations up to 3 cm away, highlight the effects of liver abscesses on the overall metabolic capacity and functionality of the liver. Continued research should focus on investigating the effect of abscess severity on overall liver function. [ABSTRACT FROM AUTHOR]

Liver abscesses (LA) continue to be an economic challenge for the beef industry. Chronic ruminal acidosis and ruminitis contribute to LA development. Fusobacterium necrophorum subsp. necrophorum, a ruminal bacterium, is the primary causative agent. Damaged ruminal, and possibly other gut regions, become susceptible to invasion and colonization by subsp. necrophorum, which reaches the liver via portal blood to cause abscesses. We hypothesize that the LA occurrence is related to the presence and concentrations of subsp. necrophorum in gut contents and epithelial tissues. Our primary objective was to detect, isolate and quantify subsp. necrophorum in gut contents and tissues in steers with experimentally induced LA. An experimental model, which included ruminal acidosis followed by intraruminal inoculation of subsp. necrophorum alone or with Salmonella enterica serotype Lubbock, was used to assess the relationship. Steers (n = 61) from three independent studies with three treatment groups were used. Treatments included: 1) forage-based diet with intraruminal inoculation of subsp. necrophorum; 2) ruminal acidosis with intraruminal inoculation of subsp. necrophorum; and 3) ruminal acidosis with intraruminal inoculation of subsp. necrophorum and S. Lubbock. Steers were euthanized 3 wk after bacterial inoculation and liver, gut contents, and tissue samples (ruminal, ileal and colonic) from steers with LA (n = 27) and with healthy livers (n = 34) were collected and subjected to culture method and quantitative PCR to isolate, detect, and quantify subsp. necrophorum. Data were analyzed by PROC GLIMMIX of SAS after summarizing frequency of isolation in various sample types within each study for steers with and without LA and converted to a binomial proportion. Concentrations were analyzed using steer as the experimental unit. The model included the fixed effect of liver status (abscessed or not) and study as the random effect. The frequency of isolation and mean concentration of subsp. necrophorum in purulent materials of LA were 100% and 3.5 x 107 Log10 CFU/g, respectively. The frequency of isolation of subsp. necrophorum from ruminal tissues of steers with LA was greater than steers with healthy livers (35.4 vs 14.5%; P = 0.04). Likewise, the concentration of subsp. necrophorum in ruminal tissues was greater in steers with LA than with healthy livers (4.2 vs 3.6 Log10 CFU/g; P < 0.001). None of the ileal and colonic tissues, except one ileal tissue in each group, yielded subsp. necrophorum. The concentrations of subsp. necrophorum in ruminal, ileal, and colonic contents did not differ (P = 0.9) between steers with LA or with healthy livers. Our data suggest that the occurrence of LA is positively related to prevalence and concentration of subsp. necrophorum in ruminal tissue, and the colonization likely serves as a source of continuous flow of bacterial emboli into the portal blood to initiate LA development. [ABSTRACT FROM AUTHOR]

Cloning is a technology by which an animal's tissue can be salvaged and replicated. Carcasses that grade USDA prime–yield grade 1 (P1) represent a rare and antagonistic outcome and are a goal for terminal sire selection in the United States. A terminal sire progeny test generated offspring for a crossbred bull (14% Zebu, 86% Angus; ALPHA), born in 2012 via somatic cell nuclear transfer (SCNT) from a carcass that graded P1. ALPHA progeny (steers and heifers) were compared against progeny of three purebred (Angus; Charolais; Simmental) reference sires. Live production traits included weaning weight, morbidity, mortality, and days on feed; carcass traits included abscessed liver frequency and lung lesion frequency, individual quality and yield grade (YG) parameters, and carcass value. Observed carcass traits for progeny from the Angus, Charolais, and Simmental sires were reflective of the carcass outcomes expected for each sire's respective breed. Calves sired by the Angus were the earliest maturing indicated by the youngest chronological age at harvest (P  ≤ 0.02) concomitant with the most backfat (P <  0.01), and the greatest marbling scores (P  < 0.01). Calves sired by the Charolais had the heaviest carcass weight (P  = 0.04), greatest cutability as assessed by USDA calculated YG (P  < 0.01) and were the heaviest muscled based on "longissimus" muscle area (P  < 0.01). ALPHA-sired calves were the most similar in carcass outcomes to calves sired by the Simmental, combining advantageous quality and yield parameters to produce an intermediate for carcass quality and yield. The economic value of moderate carcass outcomes is reflected in the carcass value per century weight, in which ALPHA-sired steers tended (P  = 0.07) to be of the greatest value compared to other sire groups. ALPHA progeny performed comparably to high-performing reference sires for terminal sire production traits and the P1 genetics in which ALPHA was cloned have economical and biological value in modern U.S. beef production. [ABSTRACT FROM AUTHOR]

Calf-fed Holstein steers (n = 115; 449 ± 20 kg) were utilized in a serial harvest experiment. A baseline group of five steers was harvested after 226 d on feed (DOF), which was designated day 0. The remaining cattle were assigned randomly to 11 harvest groups, with slaughter every 28 d. Cattle were either not (CON) or were fed zilpaterol hydrochloride for 20 d followed by a 3 d withdrawal (ZH). There were five steers per treatment in each slaughter group ranging from days 28 to 308. Whole carcasses were divided into lean, bone, internal cavity, hide, and fat trim components. Apparent mineral retention (Ca, P, Mg, K, and S) within the body was calculated as the difference between mineral concentration at slaughter and day 0. Mineral concentration at day 0 was determined from body composition of steers harvested at day 0 multiplied by individual live body weight (BW) at day 0. All data were analyzed as a 2 × 11 factorial arrangement with individual animal as the experimental unit. Orthogonal contrasts were used to analyze linear and quadratic contrasts over time (11 slaughter dates). There were no differences in concentration of Ca, P, and Mg in bone tissue as feeding duration increased (P ≥ 0.89); concentration of K, Mg, and S in lean tissue did fluctuate across DOF (P < 0.01). Averaged across treatment and DOF, 99% of Ca, 92% of P, 78% of Mg, and 23% of S present in the body were in bone tissue; 67% of K and 49% of S were in lean tissue. Expressed as gram per day, apparent retention of all minerals decreased linearly across DOF (P < 0.01). Expressed relative to empty body weight (EBW) gain, apparent Ca, P, and K retention decreased linearly as BW increased (P < 0.01) whereas Mg and S increased linearly (P < 0.01). Apparent retention of Ca was greater for CON cattle (greater bone fraction) and apparent retention of K was greater for ZH cattle (greater muscle fraction) when expressed relative to EBW gain (P ≤ 0.02), demonstrating the increase in lean gain by ZH cattle. There were no differences in apparent retention of Ca, P, Mg, K, or S due to treatment (P ≥ 0.14) or time (P ≥ 0.11) when expressed relative to protein gain. Apparent retention averaged 14.4 g Ca, 7.5 g P, 0.45 g Mg, 1.3 g K, and 1.0 g S/100 g protein gain. Expressing apparent mineral retention on a protein gain basis minimized effects of rate and type of gain, allowing for better comparison across treatments and time. Feeding zilpaterol hydrochloride did not affect apparent mineral retention when expressed relative to protein gain. [ABSTRACT FROM AUTHOR]

Holstein steers (n = 40; initial body weight [BW] = 96.0 ± 10.5 kg) were individually housed in a climate-controlled barn to evaluate potential models for the genesis of liver abscesses (LA). In this 2 × 2 factorial, steers were balanced by BW and randomly assigned to one of two treatments: 1) intravenous saline injection followed by intraruminal bacterial inoculation with Fusobacterium necrophorum subsp. necrophorum (1 × 109 colony forming unit [CFU]/mL) and Salmonella enterica serovar Lubbock (1 × 106 CFU/mL; CON; n = 20 steers); or 2) intravenous injection with 0.25 µg/kg BW of lipopolysaccharide (LPS; Escherichia coli O111:B4) followed by intraruminal bacterial inoculation of F. necrophorum subsp. necrophorum (1 × 109 CFU/mL) and S. enterica serovar Lubbock (1 × 106 CFU/mL; LBI; n = 20 steers) and 1 of 2 harvest dates (3 or 10 d post LPS infusion). Body weights were recorded on days −4, −1, 3, and 10, and blood was collected for hematology on days −4, 3, and 10, relative to LPS infusion on day 0. Intraruminal bacterial inoculation occurred on day 1. Steers from each treatment group were harvested at two different time points on day 3 or 10 to perform gross pathological examination of the lung, rumen, liver, LA (if present), and colon. Feed disappearance was less for LBI than CON (P < 0.01); however, BW did not differ (P = 0.33) between treatments. Neither treatment nor time differed for hematology (P ≥ 0.13), and no gross pathological differences were noted in the lung, liver, LA, or colon (P ≥ 0.25). A treatment × harvest date interaction was noted for ruminal pathology in which LBI had an increased percentage of abnormal rumen scores on day 3 (P < 0.01). These results suggest that an LPS challenge in combination with intraruminal bacterial inoculation of pathogens commonly isolated from LA was not sufficient to induce LA in steers within 3 or 10 d (P = 0.95) when compared to CON. Further evaluation is needed to produce a viable model to investigate the genesis and prevention of LA in cattle. [ABSTRACT FROM AUTHOR]

Our objective was to assess whether the harvest processing equipment sanitation practices in beef processing plants are sufficient to mitigate pathogen transfer. Multiple regulatory agencies across the globe require that harvest equipment be sanitized using hot water at a minimum of 82°C, with a momentary dip when a time is specified. Consequently, hot water sanitizers have been widely implemented at meat processing facilities, in particular, for knife sanitation throughout the dressing process. However, there is no standard time requirement for hot water immersion and, as such, the effectiveness of hot water sanitization is uncertain. The practice for knife sanitation at a large beef processing facility was audited and the microbial reduction that simulated the audited practice was assessed along with a momentary dip at 82°C. A five-strain cocktail of Escherichia coli and 11 knives of differing degree of usage obtained from the beef plant were used in the study. An area of 50 cm² of the upper surface of each knife was spread-inoculated with the five-strain E. coli cocktail and the knife was subsequently submerged in a water bath coupled to a water circulator for immersion at 82°C. Exposures times tested were those derived from the in-plant audit for each knife type. A knife that was similarly inoculated, but was not treated with hot water, served as a positive control. E. coli surviving the treatment were enumerated by plating. In addition, two knives that had most and least reduction of E. coli were artificially contaminated with meat prior to inoculation, by passing the knife through meat multiple times. For each condition, three independent trials were conducted. Least-squares means for log counts were separated by a post-hoc Tukey test. Mean immersion times for different knives audited ranged from 1 to 9.8 s. Immersing knives in water at 82°C significantly reduced the number of E. coli (P < 0.05; Table 1), ranging from 2.3 (air knife)- 5.5 (skinning knife 2) log units. Variation among the same knife type was observed. Momentary dip at 82°C reduced E. coli on de-boning, hook, air knife and wizard knife by 1-1.2 log (P < 0.05) and < 1 log for the other six knives (P ≥ 0.05). Treatment at 82°C for the duration of average exposure time observed during the in-plant audit of knives that had been contaminated with meat debris showed lower reductions of E. coli, compared with clean knives. Those reductions (>1.5 log units) were significant (P < 0.05). In conclusion, the duration for hot water sanitation of knives at beef processing plants achieves significant reduction of E. coli if temperature is maintained at 82°C and a momentary dip at the same temperature would be less likely to be effective. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine if ultrasound estimates of carcass quality traits could predict the final quality factors that influence purchases of consumers. Beefmaster steers (n = 86) representing two different sires were ultrasounded 48 d and 73 d before harvest using an Aloka 500 ultrasound unit, equipped with a 17.2cm probe to collect 12th rib fat thickness (BFU), 12th rib longissimus muscle area (LMAU), intramuscular fat (%FATU) and rump fat (RFU). International Livestock Image Analysis (I.L.I.A) software (Harrison, Arkansas) was used for processing images to determine BFU, LMAU, %FATU and RFU using chute side captured ultrasound images on all steers. An Ultrasound Guidelines Council (UGC) field and lab certified technician captured all ultrasound images. Carcass data collection included 12th rib fat thickness (BFC), 12th rib longissimus muscle area (LMAC) and marbling score (MS). Additionally, Warner Bratzler shear force (WBSF) and ether extraction (EE) estimates were determined on 12 to 13th longissimus muscle samples. All carcass data was collected by the Beef Carcass Research Center (BCRC) at West Texas A&M University. Data were analyzed using SAS version 9.4. Simple descriptive statistics were 1.03 ± 0.26 cm, 88.8 ± 8.61 cm², 5.02 ± 0.93, 1.27 ± 0.36 for BFU, LMAU, %FATU, and RFU, respectively. Simple descriptive statistics were 1.72 ± 0.41 cm, 90.06 ± 7.24 cm², 5.06.7 ± 0.69, 6.08 ± 1.92, and 3.34 ± 0.79 kg for BFC, LMAC and MS, EE and WBSF, respectively. Pearson correlation coefficients were 0.71 (P < 0.001) between BFU and BFC, 0.42 (P < 0.0001) between LMAU and LMAC, and 0.35 (P < 0.001) between %FATU and MS. Pearson correlation coefficients were 0.42 (P < 0.001) between EE and %FATU and 0.59 (P < 0.0001) between EE and MS. These results suggest that ultrasound measures of final body composition should be taken closer to the final harvest date to better estimate endpoints of fat thickness, longissimus muscle area and intramuscular fat in harvest ready beef cattle. [ABSTRACT FROM AUTHOR]

Growth-promoting implants are broadly used in the feedlot industry to improve growth performance and to increase production efficiencies. With cattle being fed longer and to heavier weights, there is demand for extended-release implants that payout for at least 200 d. Our objective was to evaluate feedlot growth of Synovex ONE Grower, a moderate potency (150 mg trenbolone acetate [TBA] and 21 mg estradiol benzoate [EB]), extended-release, growth-promoting implant for 200 d. At four locations (Texas, Idaho, California, and Nebraska), 200 steers (n = 800; d 0 body weight [BW] = 320.2 ± 9.5 kg) and 200 heifers (n = 800; d 0 BW = 311.5 ± 9.5 kg) were blocked by BW and randomized to 1 of 2 treatments: 1) Control , empty subcutaneous needle inserted and extracted from the middle third of one ear; 2) ONE Grower , 150 mg TBA and 21 mg EB extended-release implant administered in middle third of one ear. Treatments were commingled within pen of the same sex (n = 4/site; 2/sex/site) in a split plot design replicated across four sites. Cattle were fed finishing ration ad libitum common to each geographical region at least once daily and were observed for any abnormal health events twice daily. Treatments were administered on d 0. Mid-study implant site evaluations were performed on d 35 or 41. Initial BW was recorded on d 0 and final BW was recorded on d 200 to 204. Cattle were harvested from d 201 to 231; however, carcass data were not collected due to slaughter facility complications brought on by the COVID-19 pandemic. Data were analyzed using the PROC MIXED and PROC GLIMMIX procedures of SAS (Version 9.4, SAS Institute, Cary, NC; P < 0.05), and animal was the experimental unit. There were no treatment × sex interactions (P ≥ 0.052) for any variable. Final BW on d 200 was greater (P < 0.01) for steers and heifers implanted with ONE Grower compared to Control; ONE Grower improved final BW by 5.7% for steers and 3.9% for heifers. Overall average daily gain (ADG) from d 0 to 200 was greater (P < 0.01) for ONE Grower steers and heifers compared to Control with an increase in ADG of 13.1% for steers and 8.9% for heifers. For cattle implanted with ONE Grower, implant retention rates at d 35 or 41 were 95.7% and 96.3% for steers and heifers, respectively. There was no difference (P ≥ 0.32) in percentage deads, removals, or bullers (steers) between treatments. Synovex ONE Grower improved final BW and ADG in feedlot steers and heifers fed for at least 200 d. [ABSTRACT FROM AUTHOR]

Crossbred beef heifers (N  = 1,394; initial shrunk body weight [BW] 291 ± 9.9 kg) were used to investigate the efficacy of 10-G Armor (Life Products, Inc. Norfolk, NE; 10-G) upon feedlot performance, carcass characteristics, and fecal and subiliac lymph nodes Salmonella prevalence. Heifers were blocked by day of arrival and allocated to 1 of 20 pens (N  = 70 heifers/pen) and assigned one of two treatments (10 pens/treatment): no direct-fed microbial (CON) or 2 g/heifer/d of Lactobacillus acidophilus, Enterococcus faecium, Pediococcus pentosaceus, Lactobacillus brevis and Lactobacillus plantarum , respectively (Life Products, Inc. Norfolk, NE; 10-G). Twenty-four animals were randomly selected from each pen for Salmonella sampling. Recto-anal mucosal swab samples (RAMS) were obtained at initial processing and harvest; subiliac lymph nodes were collected at harvest. In addition, pen surface fecal pats were collected and composited by pen (10 pats per composite, 5 composites per pen) on days 0, 52, 120, and 192. Data were analyzed as a generalized complete block design, and pen served as the experimental unit. No differences were observed in live growth performance metrics (P  ≥ 0.55). Yield grade distributions did not differ between treatments (P  ≥ 0.62); however, cattle fed 10-G tended (P  = 0.06; 14.6% vs. 18.9%) to have fewer USDA Select carcasses and more (P  = 0.09; 73.6% vs. 78.0%) USDA Choice carcasses. Cattle fed 10-G tended (P  = 0.10; 9.2% vs. 12.3%) to have fewer liver abscesses and had fewer (P  = 0.04; 5.3% vs. 8.5%) severe liver abscesses. Salmonella prevalence of RAMS did not differ between treatments at initial processing (P  = 0.97; CON = 11.6%, 10-G = 11.5%) or at harvest (P  = 0.91; CON = 99.0%, 10-G = 98.6%); however, RAMS differed (P  < 0.01) in Salmonella prevalence between the two collection times. Cattle fed 10-G had a lower frequency of Salmonella positive lymph nodes (P  = 0.01; CON = 15.8%, 10-G = 7.4%) than CON. However, Salmonella log (mpn/g) of lymph nodes did not differ between treatments at harvest (P  = 0.34; CON = 0.73, 10-G = 0.34). These data indicate that cattle fed 10-G have decreased rates of severe liver abscesses without altering live animal performance or carcass characteristics. Supplementation of 10-G significantly reduced the prevalence rate of Salmonella recovered from the subiliac lymph nodes. The factors responsible for the observed difference in the effects of 10-G on Salmonella warrant further investigation [ABSTRACT FROM AUTHOR]

Liver abscesses (LA) are a polymicrobial infection and the causative agents include two subspecies of Fusobacterium necrophorum, necrophorum and funduliforme, and Trueperella pyogenes. Nucleic acidbased analysis of the purulent material of LA has indicated that Proteobacteria and Bacteroidetes were the dominant phyla, next to phylum Fusobacteria. The sporadic isolations of bacterial species of the Proteobacteria and Bacteroidetes in LA have been reported. An aspect of the pathogenesis that has not been investigated is whether bacterial pathogens in LA originate, besides the rumen, from the colon? Therefore, our objectives were to target detection and isolations of Salmonella enterica, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Bacteroides fragilis, in addition to routine isolations of F. necrophorum and T. pyogenes, from LA and also from ruminal and colonic epithelial tissues of the same animals. Liver abscesses, matched with ruminal and colonic epithelial tissue samples from 96 steers and heifers, originating from 15 feedlots, were collected at slaughter, transported to the laboratory and processed within 24 hours. Samples were subjected to anaerobic and aerobic culture methods, including enrichment and selective media for detection and isolation of S. enterica, E. coli, K. pneumonia, P. aeruginosa, and B. fragilis. Prevalence of bacterial species were shown in table 1. For each bacterium, two-sided Fisher's exact test was used to evaluate the association of its prevalence in LA with that in colon and rumen at 0.05 level. Overall, prevalence of subsp. necrophorum, subsp. funduliforme, T. pyogenes and S. enterica in liver abscesses were 86.4% (83/96), 21.8% (21/96), 35.4% (34/96) and 6.2% (6/96), respectively (Table 1). In ruminal tissue samples, prevalence of subsp. necrophorum, subsp. funduliforme, T. pyogenes and S. enterica were 6.6% (6/96), 40.6% (39/96), 11.4% (11/96) and 4.1% (4/96), respectively. Prevalence of subsp. necrophorum, subsp. funduliforme, T. pyogenes and S. enterica in colonic tissues were 18.7% (18/96), 36.4% (35/96), 0% (0/96) and 7.2% (7/96), respectively. Prevalence of E. coli, Klebsiella spp., and P. aeruginosa in LA samples were 70.8% (68/96), 92.7% (89/96), and 91.6% (88/96), respectively. Prevalence of E. coli, Klebsiella spp., and P. aeruginosa in rumen epithelial tissue samples were 17.7% (17/96), 50.0%, (48/96), and 15.6% (15/96), respectively. Prevalence of E. coli, Klebsiella spp., and P. aeruginosa in colonic tissue samples were 16.6% (16/96), 24.0% (26/96), and 12.5% (12/96), respectively. Prevalence of subsp. funduliforme in ruminal and colonic tissues was greater than subsp. necrophorum. None of the liver abscess samples yielded B. fragilis. In conclusion, E. coli was the second most dominant species detected and isolated from LA, next only to subsp. necrophorum. The greater frequencies of isolations of subsp. necrophorum and S. enterica from colonic epithelial than ruminal epithelial tissues suggest that hindgut could also be a source of pathogens involved in LA. [ABSTRACT FROM AUTHOR]

Sexed semen artificial insemination is a breeding technique that allows producers to shorten breeding seasons, optimize genetics through use of superior semen, create calves based on sex preference, and increase profitability. Sexed semen is a technology that sorts semen by differences in DNA content between X (female) and Y (male) bearing sperm. However, sexed semen practices have yet to be widely used in beef cows due to reduced sperm numbers, low conception rates, and increased costs. The objective of this study was to determine the effect of time of estrus upon fixed-time artificial insemination (FTAI) of sex-sorted semen on conception rate using two different estrous synchronization protocols. Multiparous commercial beef cows (n = 73) were randomized by age, body condition score (BCS), and days post-partum at the University of Arkansas Livestock and Forestry Research Station in Batesville. Both synchronization treatments (TRT) used a controlled internal drug releasing device (Eazi-breed CIDR; 1.38g progesterone) inserted intravaginally on d -14 of the protocol simultaneous to administration of prostaglandin F2a (PGF; 500μg cloprostenol sodium; Estrumate). In the first treatment (TRT 1; 7&7 Synch), gonadotropin-releasing hormone (GnRH; 86μg gonadorelin; Fertagyl) was administered on d -7. In the second treatment (TRT 2; 8&6 Synch), GnRH was administered on d -6. Both treatments were then administered PGF simultaneous to CIDR removal on d 0, 66 ± 2h before FTAI and administration of GnRH. Standing heat (estrus) was visually detected every 3 h for 30 min intervals between CIDR removal and FTAI. Heat detection patches were used in conjunction with visual detection of estrus. Time of estrus was signified as time of standing immobile when mounted in combination with presenting a patch score of 4 (>75% color removed). Time of estrus (TD) was deviated from time of FTAI and categorized into three equal time groups (Grp 1 = 0 to 11.0 h; Grp 2 = 11.01 to 22.0 h; and Grp 3 = 22.01 to 33.0 h). Conception rate (CR) was determined via ultrasound 37 ± 2 d after FTAI. Data were analyzed using the GLIMMIX procedure of SAS 9.4. CR did not differ by age of dam (P = 0.58), BCS (P = 0.48), or TRT (P = 0.83). However, TD had an effect on CR (P = 0.002); and resulted in CR of 45% (Grp 1), 87% (Grp 2), and 42% (Grp 3). In conclusion, these results indicate artificially inseminating cows with sexed semen between 11.01 and 22.0 h after time of standing estrus will increase pregnancy rates for multiparous commercial beef cattle. [ABSTRACT FROM AUTHOR]

To address the gaps in current scientific knowledge, the objective of the present study was to investigate the impact of fumonisin exposure on feedlot cattle intake and performance. Fifty steers were received (day 0; 361 ± 6.4 kg), housed individually and fed once daily at 0800 hours. All steers were transitioned to a dry-rolled corn-based finishing diet from days 0 to 21 and then were fed the control finishing diet until day 50. Treatment diets were formulated to achieve ≤5 (CON), 15 (15PPM), 30 (30PPM), 60 (60PPM), or 90 ppm (90PPM) of total dietary fumonisin. Steers were fed the fumonisin treatment diets from day 50 until harvest on day 160; individual animal body weights (BW) were measured on days 0, 50, 100, 150, 159, and 160. Liver, kidney, and skeletal muscle tissue samples were collected at harvest for histopathological analyses, and liver samples were further analyzed for sphinganine (SA) and sphingosine (SO) concentration. Animal performance, carcass data, and liver enzyme concentration were analyzed using a mixed model; categorical data were analyzed via nonparametric models. Contrasts were used to test for linear and quadratic responses. Throughout the study, there was no effect of treatment (P > 0.60), or a linear response (P > 0.16) from increasing fumonisin levels, on BW or dry matter intake (DMI). However, CON tended to have a lower average daily gain (ADG) than the fumonisin treatments during the fumonisin treatment period (P = 0.10), and there was a positive linear response (P = 0.02) of ADG to fumonisin during the treatment period. There were no treatment differences in hot carcass weight, dressing percentage, marbling score, ribeye area, or yield grade. There were no effects of treatment on either liver abscesses (P = 0.95) or telangiectasis (P = 0.13). We observed a treatment difference for SA and SA:SO (P < 0.01), as well as a quadratic response (P < 0.02); both SA and SA:SO increased as dietary fumonisin increased. There were no observed differences between treatments for histopathology scores of kidney (P = 0.16), liver (P = 0.25), or skeletal muscle (P = 0.59) tissue. No adverse effects were observed in steers fed increasing dietary levels of fumonisin for 110 d prior to harvest. While elevated liver amino alcohol concentration did occur, negative effects on growth and carcass characters were not observed. [ABSTRACT FROM AUTHOR]

Relationships between live body condition score (BCS) and carcass fat depots have not been well established in equine. Our study was designed to quantify the relationship between BCS and fat depot measurements from equine carcasses. Live horses (n = 429) were evaluated immediately prior to immobilization at a commercial equine processor. Horses were independently assigned a BCS by a panel of three trained evaluators; BCS was evaluated by visual appraisal and manual palpation of the neck, withers, back, ribs, behind the shoulder, and tailhead. Median BCS frequencies were: 3.0 (n = 9), 4.0 (n = 43), 5.0 (n = 116), 6.0 (n = 86), 7.0 (n = 72), 8.0 (n = 76), and 9.0 (n = 27). Sex (stallion [ n = 5], mare [ n = 159], or gelding [ n = 114]) and breed type (draft [ n = 56], stock [ n = 363], pony [ n = 8], or mule [ n =3]) were also denoted. Horses were processed for human consumption according to industry-accepted procedures under the supervision of the Canadian Food Inspection Agency. During the harvest process, all kidney–pelvic–heart (KPH) fat was trimmed from the carcass and weighed. After chilling, the marbling score was subjectively evaluated using beef grading standards. Carcass fat trim was weighed during the fabrication process. As BCS increased, hot carcass weight (HCW), absolute KPH weight, KPH expressed as a percentage of HCW, marbling score, neck fat depth, absolute weight of trimmed carcass fat, and trimmed carcass fat as a percentage of HCW increased (P < 0.01). A strong correlation (r = 0.74; P < 0.01) was detected between BCS and absolute KPH weight. Similarly, correlations between BCS and percentage of KPH (r = 0.65), neck fat depth (r = 0.60), absolute trimmed carcass fat (r = 0.58), trimmed carcass fat as a percentage of HCW (r = 0.54), marbling score (r = 0.54), and HCW (r = 0.52) were also detected (P < 0.01). These data indicate a strong relationship between subjective live BCS and objectively measured carcass fat depots in various equine breed types and sexes. [ABSTRACT FROM AUTHOR]

Life Products' direct fed microbial, 10-G, is a lipid-coated and heat protected mixed culture containing Lactobacillus acidophilus, Enterococcus faecium, Pediococcus pentosaceus, Lactobacillus brevis, and Lactobacillus plantarum. Previous small-pen research has reported inconsistent benefits to performance and carcass characteristics from feeding 10-G. The objective of this trial was to evaluate the effects of feeding 10-G on growth performance and carcass quality in yearling steers. In this randomized complete block design, 6,400 yearling steers were allocated to treatment (10-G or control) within a block (n = 16), where pen served as experiment unit. Trial diets were composed of steam-flaked corn, wheat silage, corn silage, and Sweet Bran Plus. The addition of 10-G within the treatment diet was at an inclusion of 2 g·animal-1·day-1 to provide 1x109 cfu for approximately 170 days. Mean initial body weight was 358 kg and cattle were on feed for an average of 182 days. No differences (P > 0.10) were observed between treatments for dry matter intake (control: 9.75 vs 10-G: 9.80 kg), final body weight (control: 641vs 10-G: 641 kg), average daily gain (control: 1.55 vs 10-G: 1.55 kg/d), or feed efficiency (control: 2.85 vs 10-G: 2.87). When evaluating carcass characteristics, there were no differences (P > 0.10) for hot carcass weight (control: 415 vs 10-G: 413 kg) or liver abscess prevalence (control: 17.4 vs 10-G: 18.2%). However, dressed carcass yield was decreased (P = 0.05) by 0.17% for cattle fed 10-G (control: 64.51 vs 10-G: 64.34%). No differences (P > 0.10) were observed for marbling score (control: Small29 vs 10-G: Small27), ribeye area (control: 100.00 vs 10-G: 100.00 cm²), backfat thickness (control: 1.30 vs 10-G: 1.30 cm). USDA quality grade outcomes. In conclusion, the supplementation of 10-G direct fed microbial did not influence live or carcass performance within this trial. [ABSTRACT FROM AUTHOR]

This study evaluated starch dilution with different sources of fiber from terminal implant to harvest on feedlot cattle performance, rumen buffering characteristics, and carcass outcomes. Steers (n = 416) were allocated to 48 pens in a randomized complete block design and assigned to 1 of 4 dietary treatments. Treatments were steam-flaked corn-based diets: CON; 7.5% corn stalks fed for the entire feeding period or CON followed by CS; 14.8% corn stalks, WD; 9.5% wet distillers grains with solubles and 7.5% corn stalks, or NR; 19.0% wet distillers grains with solubles and 0.0% corn stalks fed from terminal implant to harvest. Steers were transitioned to CS, WD, and NR over 6 d using a two-ration system. Within each pen, 2 steers received an indwelling rumen pH bolus and a 3-axis accelerometer ear-tag to quantify rumination. Treatment differences were considered statistically significant when P < 0.10. Dry matter (DM) and metabolizable energy (ME) intake were greatest for cattle consuming CS, intermediate for WD and CON, and least for NR (P < 0.01). The average daily gain (ADG) did not differ among treatments (P = 0.18); however, feed efficiency (G:F) was least for NR, intermediate for WD, and greatest for CS and CON (P = 0.10). Steers consuming CS had more (P = 0.08) 12th rib fat than NR, WD, or CON, but no other differences (P = 0.24) in carcass characteristics were observed. A treatment × day interaction (P < 0.01) was observed for daily rumination time and ruminal pH. Results suggest that increasing the concentration of corn stalks in the diet post-terminal implant increased DM and ME intake and rumination; replacing corn stalks with wet distillers grains with solubles improved G:F and reduced rumination with minimal impacts on ruminal pH. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The objective of this study was to compare carcass grading outcomes of progeny from a sire derived via carcass cloning to progeny from a competitive traditional purebred Angus sire. Semen was artificially inseminated into Jersey cows from an F1 sire (AxG1) derived from Prime-yield grade 1 carcass clones and a highperformance purebred Angus sire (Foundation). Calves were born at the dairy, raised in hutches on the dairy, and grown in a separate facility, all in the Texas panhandle. Cattle were later transported to Nebraska for finishing. Both steers and heifers were harvested at a commercial beef processor in Colorado and camera data were collected to assess carcass quality and yield outcomes. Data were analyzed using mixed models; treatment comparisons were tested for significance with a = 0.05. RESULTS: In live growth, calves sired by Foundation were heavier (P < 0.01) both when they entered (396.1 vs 383.0 kg) and exited (590.1 vs 568.8 kg) the feedyard. Similarly, calves sired by Foundation had heavier (P < 0.01) hot carcass weights than AxG1 (374.9 vs 361.4 kg). No difference (P = 0.27) was detected between sires for longissimus muscle area (96.6 vs 95.7 cm2) or marbling score (Moderate26 vs Moderate20). AxG1 sired calves had greater (P < 0.01) muscle area per unit of carcass weight (26.7 vs 25.9 cm2/100kg). Calves sired by AxG1 were leaner (P < 0.01) than those sired by Foundation as evidenced by less 12th rib s.c. fat (1.11 vs 1.26 cm) coupled with decreased calculated yield grades (2.34 vs 2.59). Moreover, calculated Empty Body Fat was greater (P < 0.01) for Foundation sired carcasses than those sired by AxG1 (30.0 vs 28.9 %). Foundation sired calves were represented by a greater (P < 0.05) percentage of USDA Prime carcasses (26.32 vs 17.79 %) whereas AxG1 sired calves had a greater (P < 0.05) percentage of USDA Choice carcasses (77.74 vs 69.48 %). AxG1 sired calves were represented by a greater (P = 0.04) percentage of Yield Grade 1 carcasses (27.48 vs 19.25 %). No difference in frequency of Yield Grade 2 (55.40 vs 58.00 %) or 4 (1.41 vs 1.0 %) carcasses was observed between sires. Frequency of Yield Grade 3 carcasses was greater (P < 0.01) for Foundation compared with AxG1 (23.94 vs 13.58 %). Carcass outcomes suggest that progeny sired by Foundation were of slightly higher quality whereas progeny sired by AxG1 were of slightly higher yield. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop a model for liver abscesses (LA) in Holstein steers by using an acidotic diet or acidotic diet plus intraruminal inoculation of Fusobacterium necrophorum, Salmonella enterica serotype Lubbock, and Truperella pyogenes. Holstein steers (n = 40; initial BW = 84.9 + 7.1 kg) were individually housed and randomly assigned to either a negative control diet (CON), an acidotic diet (AD), or an acidotic diet plus intraruminal inoculation with the bacterial mixture [ADB; (1 × 109 colony forming unit (CFU)/mL of each bacteria]. Steers in AD and ADB were cycled on (3 d) and off (2 d) a high-starch diet 20 days before intraruminal inoculation of ADB. Following inoculation, AD and ADB remained on the acidotic diet for the remainder of the study. Ruminal pH boluses were randomly inserted into 19 steers across treatments to monitor ruminal pH throughout the study. Steers were euthanized and necropsied to record gross pathology on the lung, rumen, liver, and colon. Culture techniques were used to determine the prevalence inoculated bacteria within LA. Quantitative polymerase chain reaction methods were used to quantify F. necrophorum in rumen tissue. Data were analyzed as a completely randomized design with animal as the experimental unit, where an a of = 0.05 determined significance. Liver abscess prevalence was 43% in ADB vs. 0% in AD and CON treatments (P < 0.01). Ruminal damage was 51.1% greater in ADB than in AD and 78.6% greater than in CON (P ≤ 0.05). There were no pathological differences in the lungs and colons among treatment groups (P ≥ 0.14). There was a treatment × time interaction for ruminal pH, where pH decreased below 5.6 in AD and ADB calves during each cycle of the acidotic diet (P < 0.01). The ADB contained a greater concentration of F. necrophorum subsp. Necrophorum and subsp. Fundliforme within rumen tissue (P = 0.03). Of the LA cultured, 100% contained F. necrophorum, 50% S. enterica, and 0% contained T. pyogenes. The F. necrophorum subsp. Necrophorum was phylogenetically typed and identical to the strain (FN-8LI) infused in the bacterial inoculation. These data suggest that acidotic diet in combination with intraruminal inoculation of the bacterial mixture is sufficient to induce liver abscesses and provides insight on possible mechanisms and origins of LA. Further studies are needed to validate these results and determine if this model may be used to study novel intervention methods. [ABSTRACT FROM AUTHOR]

Most research surrounding liver abscesses involves post-hoc evaluation of naturally occurring abscesses in production settings. Few studies have been designed to experimentally induce abscesses with the purpose of identifying a time course, causality, and associated physiological implications. Therefore, we set out to develop a minimally invasive, reliable, and repeatable model to induce liver abscesses in calves in a controlled research environment to elucidate the genesis and etiology of the disease, with the ultimate goal of developing abscess reduction strategies. Experiment 1 was an attempt to induce abscesses by intraruminal inoculation with Fusobacterium necrophorum, Salmonella lubbock, and Truperella pyogenes (FST) following an intravenous lipopolysaccharide challenge. Holstein steers were harvested 3- and 10-d after inoculation, but no abscesses were detected. Experiments 2 and 3 involved diet manipulation by cycling calves on and off a high-starch, acidotic diet followed by intraruminal inoculation of microbes. In Experiment 2, Holstein calves were fed a negative control diet, an acidotic diet, and an acidotic diet plus bacterial inoculation with FST. No abscesses formed in the control or acidotic diet calves, but 43% of calves fed the acidotic diet with FST inoculation formed liver abscesses, suggesting that acidosis alone is insufficient to produce abscesses. In Experiment 3, treatments consisted of Holstein steers fed a negative control, an acidotic diet, an acidotic diet plus ruminal Fusobacterium necrophorum (F), and an acidotic diet plus Fusobacterium and Salmonella (FS). Again, there were no abscesses in the control or calves fed an acidotic diet alone; however, 40% of calves receiving F presented with an abscess, and 50% of the calves that received FS presented with abscesses. These data suggest that ruminal acidosis in conjunction with a ruminal load of pathogens commonly associated with liver abscesses provides a model that will induce liver abscesses. While the role of barrier dysfunction in the rumen and the lower gastrointestinal tract in formation of abscesses is not fully understood, this work provides a foundation to further explore the etiology of this disease and potential mitigation strategies. [ABSTRACT FROM AUTHOR]

One hundred and eighty beef bulls (BW = 337 ± 10.9 kg) were blocked by BW (6 blocks) and assigned randomly to one of three treatments on day 0: 1) INJ; received 1 mL (100 mg Zn) of a Zn solution in each testis, 2) BAN; received blood-restrictive rubber band placed upon the dorsal aspect of the scrotum, and 3) BUL; bulls with testicles remaining intact. Cattle were grouped by weight block in a randomized complete block design (three treatment pens/block and 10 cattle/pen) and harvested by block on three separate dates when blocks reached similar BW and visual subcutaneous fat thickness depth. Striploins were removed from the left carcass sides, vacuum packaged and aged for 14 d, and then frozen at −20 °C. Frozen striploins were sliced into 2.54-cm-thick steaks and remained frozen until analyses. Steaks (n = 3/animal) were used to assess consumer acceptability via consumer taste panel (n = 152 panelists), Warner-Bratzler shear force, percentage cook loss, and cooked color values. Data were analyzed using mixed model procedures; pen was the experimental unit for all dependent variables. Hot carcass weights and LM area were greater (P < 0.01) for the INJ and BUL treatments compared with BAN. Mean yield grade did not differ between treatments (P = 0.12), although BAN carcasses had smaller LM area (P < 0.01) than BUL or INJ carcasses. Percentage of USDA Choice or better carcasses was greater (P < 0.01) for BAN than INJ and BUL treatments. Consumer panelists detected a difference in perceived tenderness; BAN steaks had greater (P = 0.02) tenderness scores than BUL steaks, whereas INJ steaks were intermediate. Panelists rated juiciness of BAN steaks greater (P < 0.01) than either BUL or INJ steaks. Panelists rated beef flavor greater (P = 0.01) for BAN and BUL steaks than INJ steaks. Overall acceptability was greater (P < 0.01) for BAN compared with INJ steaks, whereas BUL steaks were intermediate. Percentage cook loss of striploin steaks (P = 0.47) and Warner-Bratzler shear force values (P = 0.11) did not differ. Cooked color lightness (L *) and redness (a *) values were not affected (P ≥ 0.23) by treatment. Striploin steaks from BAN and BUL treatments had greater (P = 0.02) yellowness values (b *) than INJ steaks. The ratio of red-to-brown (630:580 nm) of cooked striploin steaks was greater (P = 0.05) for INJ than either BAN or BUL treatments. Carcass and palatability outcomes of INJ were more similar to BUL than BAN, suggesting limited efficacy of INJ in mature beef bulls at feedlot entry. [ABSTRACT FROM AUTHOR]

An experiment was conducted to evaluate the fabrication yields of carcasses from beef steers supplemented zilpaterol hydrochloride (ZH) and fed at maintenance (MA) or ad libitum (AB) intake levels. Beef steers (n = 56) from a common sire were blocked (n = 28 per block) by terminal growth implant and sorted into pairs by BW. Four pairs (n = 8) were harvested on day 0; the remaining 24 pairs (n = 48) were assigned to a dietary intake level (MA or AB) and days on feed (28 or 56 d). Within pairs of MA or AB intakes, steers harvested on day 56 were randomly assigned to supplementation of ZH (90 mg·d-1 per steer) for 20 d followed by a withdrawal period of 4 d or control (C). Steers (BW = 603.5 ± 48.1 kg) were harvested at a commercial processing facility. After a 24-h chill period, standard USDA grading procedures were used to derive a calculated yield grade and quality grade. Following grading, left carcass sides were transported to the West Texas A&M University Meat Laboratory for fabrication. Each side was fabricated into subprimals to determine individual red meat yield (RMY), trimmable fat yield (TFY), and bone yield (BY). A mixed model was used for analysis; fixed effects included treatment combinations and random effects included block and pairs. Single df contrasts tested day 0 vs. 28, day 0 vs. 56, day 28 vs. 56, MA vs. AB, and C vs. ZH. Yield of chuck eye roll differed (P = 0.05) by days on feed (0 d = 4.14, 28 d = 4.11, 56 d = 4.55%). Similarly, eye of round yield was impacted (P = 0.02) by days on feed (0 d = 1.51, 28 d = 1.37, 56 d = 1.36%). Additionally, brisket yield was altered (P < 0.01) by days on feed (0 d = 4.08, 28 d = 3.56, 56 d = 3.48%) and treatment (C = 3.34, ZH = 3.61%). For remaining subprimals, no differences (P = 0.15) were detected. Furthermore, results indicated that RMY tended (P = 0.07) to differ by treatment (C = 61.35, ZH = 63.67%). Comparatively, TFY was impacted (P = 0.04) by intake (MA = 20.44, AB = 23.33%). Results from this study indicate that a MA intake level during the last 56 d of the finishing period concurrent with ZH supplementation impacts subprimal yields as well as carcass RMY and TFY of beef steers. [ABSTRACT FROM AUTHOR]

Crossbred beef bulls (n = 180) were blocked by initial BW (337 ± 10.9 kg; six blocks) and assigned randomly to one of three treatments on day 0: 1) INJ; received 1 mL (100 mg Zn) of a Zn solution in each testis, 2) BAN; received blood- restrictive rubber band placed around the dorsal aspect of the scrotum, 3) BUL; bulls with testicles remaining intact in a randomized complete block design (three treatment pens per block and 10 cattle per pen). A subset of 54 animals (n = 3 per pen) was fitted with accelerometers on day 0 to quantify behavior variables continuously for 28 d. Testis width and scrotal circumference, and serum haptoglobin (days 0, 1, 3, 5, 7, and 14) and testosterone concentrations (every 28 d until slaughter) were also determined for the subset. During the slaughter process, testes from INJ and BUL were collected to assess final testes weight and for histopathological evaluation. Data were analyzed using a mixed model (a = 0.05); pen served as the experimental unit for all dependent variables. Final BW was greater (P < 0.01) for INJ and BUL compared to BAN (672, 686, and 611 kg, respectively; SEM = 4.4). Overall ADG and G:F were greater (P≤ 0.03) in INJ and BUL than BAN; whereas, DMI was similar between treatments for the study duration (P = 0.46). Histopathological evaluation (n = 13; INJ = 7; BUL = 6) indicated that INJ testes were degenerative and reproductively nonviable whereas BUL testes were normal. Serum testosterone concentrations on day 168 were similar (P = 0.14) between INJ and BUL whereas after day 14, BAN was nondetectable; however, initial serum testosterone concentrations were similarly low across treatments. Serum haptoglobin concentration was greater (P < 0.01) in INJ than BUL and BAN on days 1, 3, 5, and 7. Scrotal circumference (P = 0.08) and testis width (P = 0.07) on day 168 tended to be greater for BUL than INJ. Motion index (P ≤ 0.02) and step count (P = 0.04) was greater in BUL and INJ compared to BAN cattle during the 28 d monitoring period. No difference in standing time (P ≥ 0.85) or lying bouts (P = 0.35) occurred. Zinc injection resulted in sterilization but did not cause complete cessation of testicular function evidenced by testosterone concentrations more similar to BUL than BAN. This resulted in overall increased BW and G:F for INJ vs. BAN, yet the acute phase response was markedly greater directly after Zn injection. Collectively, Zn injection resulted in outcomes more similar to BUL than BAN, implying minimal efficacy of INJ as a castration method in older bulls arriving to the feedlot. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of days on feed (DOF) on performance, health, carcass, and organ characteristics of composite Angus x Holstein heifers (n = 3,676). At time of arrival (d 0), heifers from a single source were placed into large (~300 animal) pens at two commercial feedlot locations in the Texas Panhandle. At administration of final implant (Revalor® 200; d 240), heifers, within lot, were randomly assigned to one of four smaller pens, creating a block (location A block n = 6, location B block n = 7). Pens within blocks were randomly assigned to treatment (323, 344, 365, or 386 DOF). Data were analyzed using DOF as the fixed effect; block was nested within location as a random effect. Linear and quadratic effects were also tested; pen was experimental unit (n = 52). Heifer DMI did not differ across DOF (P = 0.72). Heifer ADG decreased linearly (1.52, 1.37, 1.31, and 1.27 kg/d; P ≤ 0.01). Heifer HCW (372, 387, 401, and 414 kg), longissimus dorsi muscle area (88.63, 89.55, 90.80, and 91.95 cm2), marbling score (535, 553, 563, and 594) and percentage of Prime QG (6.6, 11.2, 12.8, and 19.0 %) linearly increased (P ≤ 0.01) as DOF increased. Frequency of liver scores (edible, minor, or major abscess) did not change over DOF (P ≥ 0.82). Frequency of ideal heart score linearly decreased with DOF (53.0, 44.3, 25.7, and 15.0 %; P ≤ 0.01). Frequency of YG 3 did not change (P = 0.68), however YG 4 linearly increased with DOF (6.2, 12.0, 14.0, and 22.5 %; DOF P ≤ 0.01). Data collected in this trial indicate that DOF led to increased HCW, LM area, marbling, YG, and QG with minimal changes to DMI or liver scores for Angus x Holstein heifers. [ABSTRACT FROM AUTHOR]

Feedlot cattle (n = 50) were ultrasounded to compare ultrasound vs carcass measurements, and to test the hypothesis that the left and right side of an individual animal are not statistically different during the Ultrasound Guidelines Council (UGC) Carcass Certification live animal exam at West Texas A&M University (WTAMU). Cattle (steers, heifers and bulls) represented a variation in breed types. A UGC certified technician scanned the cattle at the WTAMU Research Feedlot on their right side. The following day, the same technician scanned animals on the left side. Carcass ultrasound measurements included 12-13th ribeye area (REAU), subcutaneous fat thickness (FTU), intramuscular fat percentage (IMFU) and rump fat thickness (RFU). Carcass measures included 12-13th ribeye area (REAC) and fat thickness (FTC) along with marbling score (MS). Correlations between REAC and REAU were 0.83 for the left side and 0.80 for the right side, correlations between REAC left vs right were 0.94 and REAU left vs right were 0.77 (P < 0.01). A minor difference (2.27 cm2) in left vs right sides of REAC (P = 0.04) was detected. A larger difference (4.03 cm2) in left vs right REAU (P < 0.01) was noted; REAC right vs REAU right also differed (P < 0.01) by 8.13 cm2 with REAU being larger. No differences were observed between FTC left vs right (P = 0.26), FTU left vs right (P = 0.94) or FTC right vs FTU right (P = 0.15). A difference was detected between the FTC left and FTU left (P = 0.01). Correlations between REAU/REAC, FTU/FTC, and IMFU/IMFC were all significant (P < 0.05). These data present strong correlations between ultrasound and carcass traits, as well as the point that one side of an animal should be scanned as opposed to another side. [ABSTRACT FROM AUTHOR]

Two groups (light = 740 lbs and heavy = 942 lbs) of Akaushi cross steers (n = 20), were ultrasounded for carcass traits by an Ultrasound Guidelines Council Certified Technician every 28 days to quantify differences in intramuscular fat deposition occurring in three distinct muscles (longissimus dorsi, biceps femoris and semitendinosus). Cattle were fed at the West Texas A&M University Research Feedlot and scanned with an Aloka 500 ultrasound unit using Beef Image Analysis (BIA) Feedlot software from Designer Genes Technologies, Inc. (Harrison, AR). Carcass ultrasound measurements included 12-13th rib ribeye area (REAU), subcutaneous fat thickness (FTU), intramuscular fat percentage along the longissimus dorsi (IMFULD), rump fat thickness (RFU) as well as intramuscular fat percentage of the biceps femoris (IMFUBF) and semitendinosus (IMFUST). A difference was detected in IMFULD for the duration of the study (P < 0.05). However, no differences occurred from day 0 to day 56 (P = 0.34), or from day 84 to day 140 (P = 0.17) for IMFULD. There was a slight numerical decrease (0.1505%) in IMFUBF from day 0 to day 56, with an increased difference from day 56 to day 84 (P < 0.05). There was a positive change from 4.113% to 5.728% in the heavy group (P = 0.08) and a change from 4.113% to 4.456% in the light group (P = 0.42) for IMFUBF. There was a significant change in IMFUST from day 56 to 84 (P < 0.05). Of note, there was a decrease in IMFULD, IMFUBF and IMFST from day 140 to day 168 which could be associated with adverse winter weather events. The data present a positive increase throughout all muscles studied for beef cattle while on feed, though weather events have the possibility to negatively affect gains more rapidly than progressive effects associated with feed and growth. [ABSTRACT FROM AUTHOR]

The association of lung abnormalities with carcass performance was evaluated on data from 60,843 carcasses housed in the West Texas A&M University Beef Carcass Research Center database collected from 2010 to 2021 to quantify the relationship of lung health and carcass performance. Lung outcomes were scored as severity of consolidation (N = Normal and free of consolidation, 1 = 5 to 15% consolidation, 2 = 15 to 50% consolidation, 3 = >50% consolidation) and presence of fibrin tags (M = Minor fibrin, E = Extensive fibrin). Lung consolidation had a strong and detrimental effect (P < 0.01) on hot carcass weight, with lung scores of 1, 2, and 3 resulting in 4.2, 13.3, and 29.9 kg less carcass weight compared with carcasses with normal lungs. Minor and extensive fibrin tags (3.5 kg and 7.1 kg), independent of consolidation, resulted in lighter carcasses (P < 0.01) compared with those with normal lungs. Lung score did not have an effect on marbling score. Both lung tissue consolidation and fibrin tags effected 12th rib fat thickness; lung consolidation (-0.09 to -0.21 cm) and fibrin tags (-0.14 to -0.19 cm) resulted in and less (P < 0.01) 12th rib fat thickness compared with carcasses with normal lungs. Similarly, LM area was reduced (P < 0.01) in carcasses with lung consolidation (-1.5 to -5.5 cm2) or presence of fibrin tags (-2.3 to -2.7 cm2) compared with carcasses with normal lungs. Additionally, severity of lung consolidation and presence of fibrin tags reduced (P < 0.01) calculated yield grade; lung consolidation and fibrin tags resulted in a 0.08 to 0.20 and 0.09 to 0.13 reduction in overall yield grade. These data indicate that lung health is an important factor that impacts carcass performance, particularly carcass weight and yield grade parameters. [ABSTRACT FROM AUTHOR]

The objectives of this research were to determine if an F1 USDA Prime, yield grade 1 sire produced from the WTAMU PrimeOne Project (Sire A) was a competitive sire for producing dairy composites when compared to a purebred Angus sire (Sire B), and to evaluate any subsequent reproductive impact of sire on dam. Dairy cows (n = 1,930) were artificially inseminated resulting in 763 pregnancies with 564 births and 536 live calves. Data was collected at a large commercial dairy and analyzed using SAS 9.4 with sire as fixed effect; lactation, breeding technician and services per conception were random effects. Individual animal was experimental unit (n = 536). Conception rates were 40% for Sire A and 31% for Sire B (P ≤ 0.01). Average gestation length (GL) was 284-d and 280-d for Sire A and B, respectively (P ≤ 0.01). Calves by Sire B reported lower average birth weight (BW) than those by Sire A (P ≤ 0.01) with no difference in calving ease score (CE) (P = 0.24). There was no difference in 60-d (P = 0.58) or 120-d calf weights (P = 0.47). However, calves by Sire B reported higher average daily gains at both 60- (0.61 and 0.58 kg; P ≤ 0.01) and 120-d (0.70 and 0.67 kg; P = 0.03). Sire had no effect on morbidity (P = 0.62) or mortality (P = 0.25). Post-partum interval (PPI) and time from first estrus to conception were not different between sires (P = 0.19; P = 0.14). BW and CE did not affect PPI or time from first estrus to conception. Data from this trial indicates the cloned progeny sire increased conception rates, but the purebred Angus sire was more favorable for GL, BW and progeny growth performance. Neither sire negatively impacted subsequent reproductive performance of the dam. [ABSTRACT FROM AUTHOR]

Throughout recorded history of beef cattle improvement, the pendulum of cattle type has swung from large, old and extremely fat to extremely short in stature and overfinished to extremely tall in stature and lean to moderate in size and overfinished. During all of these transitions, the underlying growth principles of muscle, fat, and bone have remained constant. As animals age, muscle growth, as well as independent accumulation of water and protein increases at a decreasing rate whereas fat growth increases at an increasing rate. Beef carcass grading records reported by USDA indicate that percentage of Prime and Choice grade carcasses increased consistently from 62.9% in 1956 to a peak of 97.7% in 1987. Beginning in 1988, a notable decline in percentage of Prime and Choice began that plateaued from 1997 to 2007; USDA records indicate that Prime and Choice percentage was the lowest in history in 2006 at 59.0%. Since 2007, percentage of carcasses grading Prime and Choice has again steadily increased to 80.7% in 2021. Concomitantly, percentage of carcasses with yield grades of 4 or 5 has increased from a recent low of 1.3% in 1997 to 16.2% in 2021 - the highest percentage of overfinished cattle since records began. The recent improvement in quality is primarily the result of an industry paradigm shift from marketing of live animals and selling beef as a commodity to the marketing of carcasses and selling beef as premium branded products. Cattle feeders have been incentivized to market cattle as carcasses rather than live animals primarily due to the economics associated with carcass transfer. Carcass transfer is the proportion of live animal gain that is retained as carcass gain - this value increases at a decreasing rate during the finishing period and typically ranges from 75 to 85% of live animal gain. Our current yield assessment metric was developed in the late 1950s and is representative of cattle of that period, not modern cattle. The yield grade estimates 40% of the variation in cutability of beef-type cattle carcasses and 0% of the variation in cutability of dairy-type cattle. Opportunity exists to improve beef carcass yield estimation. The goal of our beef production system is to provide domestic and foreign customers with premium quality products that meet their expectations for palatability. Objective shear force values indicate that steaks from the rib and loin have continued to become more tender during the last 3 decades. [ABSTRACT FROM AUTHOR]

ABSTRACT Sixteen beef carcasses were harvested to determine the effect of pre-rigor foreshank positioning on the ultimate sarcomere length and objective tenderness values of seven chuck muscles. After final inspection, the left side foreshank was positioned caudal to the point of the shoulder and secured until the completion of rigor. The right side foreshank served as the control and was allowed to hang in the normal position, cranial to the point of the shoulder. Biceps brachii, infraspinatus, pectoralis profundus, serratus ventralis, supraspinatus, teres major and triceps brachii muscles were excised from each carcass half for sarcomere length and Warner-Bratzler shear force determinations. Results indicate that sarcomere length was altered (P < 0.05) for all muscles. When the foreshank was placed in the caudal position pre-rigor, both the serratus ventralis and triceps brachii muscles had higher (P < 0.05) shear values than when the foreshank was allowed to remain in its natural position. PRACTICAL APPLICATIONS As the beef industry continues to search for methods to add value to the chuck, these data may offer insight into a practical method to increase sarcomere length and enhance palatability and marketability of underutilized muscles. [ABSTRACT FROM AUTHOR]

Cattle diet, marbling and wet aging can affect eating quality and consumer preference of beef. The objective of this study was to assess the relationship of cooked volatile compounds and consumer sensory traits of New Zealand grass-fed strip loin steaks in comparison to US grain-fed strip loin steaks from five different USDA quality grades, wet-aged for 7, 21 and 42 days. Beef strip loins (n = 200; 20 per USDA quality grade/fed cattle type) representing five USDA quality grades (USDA Prime, Top Choice, Low Choice, Select and Standard) and two fed cattle types (New Zealand grass-finished and US grain-finished) were used. Steaks were cooked to a target internal temperature of 71°C and served to consumer panelists (n = 600; 120 per five different cities in the US). Volatile analysis (n = 600) was performed on cooked samples, and quantitation was conducted by an internal standard calibration with authentic standards. Statistical analyses were conducted using the FACTOR procedure of SAS. A principle component analysis (PCA) showed relationships of volatile compounds, treatments, and consumer ratings. PC1 explained 17.17% of the variation and PC2 explained 10.96% of the variation. Consumer flavor liking was most closely associated with ethanol and treatments grass and grain Prime aged 42d. The majority of the alcohols and n-aldehydes were associated with the 7d grain treatments including grain Top Choice, Low Choice and Select. The Maillard derived compounds were grouped together and most associated with grass Top Choice 42d and the consumer attributes. Methional was closest to many grass treatments including grass Top Choice 7d, Low Choice 7d, Standard 7d, Prime 7d and Standard 21d. Although associations were evident between volatile compounds and consumer sensory attributes, they were not strongly related. [ABSTRACT FROM AUTHOR]

Heifers (n = 1,394; 291 ± 9.9 kg) were used to test the effects of a direct-fed microbial (10-G) on live growth performance and carcass characteristics. Heifers were blocked by arrival day and randomly allocated to treatment (0 or 2g/animal/d; CON and 10-G, respectively) in a randomized complete block design with ten pens per treatment. Heifers were fed for an average of 192 days. Growth and carcass outcomes were analyzed using mixed models with pen as experimental unit and block as random effect. Dry matter intake (P = 0.63), average daily gain (P = 0.69), gain:feed (P = 0.95) and final body weight (P = 0.79) did not differ between treatments. Neither deads and removals (P = 0.52) nor first or second treatment morbidity rates (P = 0.84) were different between treatments. Hot carcass weight (P = 0.19), dressed carcass yield (P = 0.33), 12th rib fat depth (P = 0.73), ribeye area (P = 0.13), calculated empty body fat (P = 0.71) or marbling score (P = 0.20) were not different between treatments. Yield grade distributions did not differ between treatments (P = 0.44), however cattle fed 10-G tended (P = 0.09; 15.78 vs 20.34%) to be represented by fewer USDA Select carcasses. Livers from cattle fed 10-G tended (P = 0.10; 1.02 vs 2.19%) to have a lower frequency of abscesses when compared to CON. Heifers fed 10-G also had fewer (P < 0.05; 5.27 vs 8.51%) severe liver abscesses. These results suggest that supplementing fed beef heifers with 10-G decreased rates of severe liver abscesses without altering live animal performance or carcass characteristics. [ABSTRACT FROM AUTHOR]

Bovine liver abscess outcomes of individual animals (n = 989,296) were observed from 2013 to 2021 on a pen (n = 6,420) basis to quantify liver abscess prevalence and severity, as well as other liver abnormalities such as liver flukes. Cattle originated from 122 feedlots located in Arizona, Colorado, Idaho, Kansas, Minnesota, Missouri, Nebraska, Oklahoma, and Texas. Livers were audited at eighteen different beef abattoirs. Observational categories included sex (heifer, steer), cattle type (Holstein, beef-type), and pen count. Pen counts were grouped (< 40, 41-80, 81-160, 161-320, and >320) to quantify the association of pen size on liver abscess outcomes. Data were analyzed as a series of binomial proportions using generalized linear mixed models with fixed effects of observational categories (cattle type, feedyard location, pen size and sex). Cattle fed in Oklahoma or Texas exhibited greater (P < 0.01) frequency of liver flukes (3.2% vs 0.5%) than cattle fed in Colorado or Nebraska. Cattle fed in Colorado, Kansas, Missouri, Nebraska, Arizona, and Oklahoma exhibited fewer (P < 0.01) total abscesses (23.5%, 26.0%, 23.6%, 19.3%, 16.9%, and 18.1%) than cattle fed in Idaho, Minnesota, and Texas (36.4%, 36.4%, and 33.2%). Beef-type cattle were observed to exhibit fewer (P < 0.01) total abscesses (22.0% vs 41.1%) and fewer (P < 0.01) severe abscesses (10.2% vs 26.4%) than Holstein cattle. Likewise, native heifers exhibited fewer (P < 0.01) total abscesses (20.6% vs 23.3%) and fewer (P < 0.01) severe abscesses (9.3% vs 11.1%) than native steers. Abscess prevalence differed as a function of pen size. Both total abscess and severe abscess rates decreased (P < 0.01) as animal count within a pen increased (32.66%, 27.47%, 27.86%, 23.17%, and 20.33%; 17.20%, 14.48%, 14.80%, 11.45%, and 9.14%). These results suggest liver abscess prevalence and severity is affected by a wide range of factors. [ABSTRACT FROM AUTHOR]

Sixty-eight (68) crossbred steers were evaluated using two real-time, B-mode ultrasound units to estimate final carcass attributes. The cattle were ultrasounded at the West Texas A&M research feedlot (Canyon, Texas) and carcass data was collected at the West Texas A&M Meats Laboratory (Canyon, Texas) or Tyson Fresh Meats (Amarillo, Texas). Objectives of the study were 1) to compare ultrasound live animal data to carcass attributes at harvest 2) to evaluate the performance differences between the ALOKA 500 (ALK) and the EVO ultrasound units All ultrasound images were captured by the same Ultrasound Guidelines Council (UGC) certified technician with images being processed at the UltraInsights Laboratory (Pierce, Colorado). The correlations between 12th rib fat thickness of the carcass (FTC) and ultrasound (FTU) were 0.84 for the ALK and 0.85 for the EVO, with no differences being found between the two units (P = 0.15). Correlations between the 12-13th rib carcass ribeye area (REAC) and ultrasound ribeye area (REAU) were 0.69 for the ALK and 0.66 for the EVO. There was no difference in REAU size between the two units. Carcass marbling score (MS) and ultrasound intramuscular fat (IMFU) correlations were 0.78 for the ALK and 0.84 for the EVO. The IMF data were found to be different between the two units, with the EVO measuring a mean IMFU value of 6.03 and the ALK a value of 5.26 with the change of 0.77 being different (P < 0.01). It is concluded that both ultrasound units performed favorably when predicting FTC and marbling score but were not highly correlated for REAU. It was found that the predictions between the two units on FT and REA were the same, though the EVO was higher on both. The IMFU values between the ALK and EVO were different, with the EVO again predicting higher values. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of a single slow-release implant compared to two re-implant programs administered at either 120 days on feed (DOF) or 80 days from harvest on performance, carcass characteristics, and activity of serially harvested feedlot cattle. Using a randomized complete block design, steers (n = 4,680) were randomly assigned to 72 pens and 1 of 12 treatments in a 3 × 4 factorial arrangement. Treatments were either a slow-release implant (SR), an initial slow-release implant followed by re-implant at 120 DOF (SR+RI-120), or an initial slow-release implant followed by re-implant 80 days from harvest (SR+RI-80) administered to cattle harvested at 166, 180, 194, or 208 DOF. A 3-axis accelerometer ear-tag was used in a subset (n =1,080) of animals to quantify rumination time and activity. No interactions (P = 0.09) were observed for implant × DOF. Implant did not affect (P = 0.25) final BW, ADG, or DMI, but re-implanted steers had a greater (P < 0.01) G:F ratio than SR. Re-implanted steers also had greater (P = 0.03) HCW, dressed yield, and ribeye area, but less (P < 0.01) backfat, marbling, and empty body fat (EBF) compared to SR. Re-implanted steers had less (P < 0.01) choice and yield grade 4 and 5 carcasses than SR steers. As DOF increased, HCW, dressed yield, backfat, marbling, and EBF increased linearly (P < 0.01). The percentage of choice and yield grade 4 and 5 carcasses also increased (P < 0.01) linearly with additional DOF. An implant × day effect (P < 0.01) for weekly activity minutes suggests re-implanted steers had greater activity after re-implant administration. Re-implanting within the payout period of a slowrelease implant increases feed efficiency, HCW, dressed yield, and activity minutes, but decreases carcass fatness and reduces quality grade regardless of timing of secondary implant administration. [ABSTRACT FROM AUTHOR]

Coarse roughage, such as corn stalks, in feedlot diets aids in the formation of a fibrous mat within the rumen. The fibrous mat supports rumen health, buffers pH, and reduces acidosis risk in cattle consuming high-concentrate diets. Excess roughage can increase physical fill, thus lowering the animal's ability to consume enough energy for efficient growth. The objective of this experiment was to quantify feedlot growth performance, rumination, ruminal pH and carcass quality and yield outcomes of cattle consuming a finishing diet with increasing levels of roughage. Fifty-one steers (initial BW = 295 + 11 kg) were randomly allocated to 1 of 3 dietary treatments; 5% (5CS; n = 18), 10% (10CS; n = 17), or 15% (15CS; n = 16) corn stalks (DM basis) in a steam-flaked-corn based finishing diet. Steers were fitted with a sensory collar that recorded rumination (min/d) and one-half of the steers (n = 27) received a rumen bolus that continuously monitored pH. The experiment was conducted using a randomized complete block design. Data were analyzed using a mixed model; treatment was a fixed effect and block was a random effect. As CS inclusion increased, we observed increased DM intake (P = 0.01; 7.7, 8.2, and 8.5 kg/d, respectively), decreased gain efficiency (P < 0.01; 0.18, 0.16, and 0.14 kg/kg DM, respectively), and a tendency for decreased ADG (P = 0.09; 1.34, 1.33, and 1.22 kg/d, respectively). Ruminal pH was highest (P < 0.01) for 15CS (6.28) and similar for 5CS and 10CS (6.10). Steers spent more time ruminating (P < 0.01) when consuming the 10CS diet (361 min/d) and least with 5CS diet (279 min/d). Increasing CS to 15% decreased rib fat thickness (P = 0.01), decreased calculated YG (P = 0.02), and decreased marbling score (P < 0.01) compared with the 5CS and 10CS treatments. Feeding excess corn stalks (≥ 15%) may prevent adequate energy intake, thus diminishing feedlot growth performance and carcass merit. [ABSTRACT FROM AUTHOR]

Cloning is a technology by which genetic material can be salvaged and replicated for future herd improvement. Carcasses that grade USDA Prime – Yield Grade 1 (P1), represent a rare and antagonistic outcome and are a goal for terminal sire selection. The WTAMU PrimeOne project resulted in two bulls and three heifers born in 2012–2014 through somatic cell nuclear transfer from carcasses that graded P1. Mating of a crossbred bull (14% Zebu, 86% Angus; Alpha) to three identical heifers (Gammas) subsequently produced progeny (AxGs) via embryo transfer. Alpha progeny (steers and heifers) were compared against progeny of three purebred (Angus; Charolais; Simmental) reference sires in a terminal sire test. Live production traits and carcass traits were measured. A completely randomized experimental design structure was used; data were analyzed using a mixed model with sire as the fixed effect and harvest date, sex, and pen as random effects. For live cattle traits: Alpha progeny were the lightest (P = 0.03) in weaning weight (kg), tended (P = 0.08) to have the lowest frequency of morbidity, and Alpha-sired heifers tended (P = 0.07) to have the heaviest weight (kg) at feedlot arrival. For carcass traits: Alpha-sired heifers and steers had the largest (P < 0.01) longissimus muscle area next to the Charolais sire, Alpha-sired steers had the lowest (P P P < 0.01) for steers; Alpha-sired steers had the greatest value per cwt. Progeny data from Alpha and an AxG sire (AG1) is being used to generate EPDs for WTAMU PrimeOne cattle. These data indicate Alpha progeny performed comparably to high performing reference sires from multiple breeds for terminal sire production traits. [ABSTRACT FROM AUTHOR]