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As perennial warm-season grasses mature in late summer, dry matter intake (DMI) of growing heifers may be limited due to low protein (7.2 ± 2.5 %) and increased NDF content (67.5 ± 2.7%), which may compromise growth potential. Cottonseed meal (CSM) supplementation may improve forage digestibility by increasing rumen degradable protein offered, but research regarding the specific effects of CSM supplementation on gain performance and composition of gain in heifers is limited. It was hypothesized that supplementation of CSM to heifers grazing mature forage would have greater growth performance compared with heifers not receiving CSM. Objectives for this experiment were to compare the effects of two CSM supplementation strategies on the growth performance of heifers grazing mature summer forage. In two consecutive summers, commercial Angus cross heifers (n = 63) weighing 266.08 ± 32.74 kg were blocked by BW (light, medium, and heavy) and allocated to 9 paddocks (1.64 ha) of WW-B. Dahl Bluestem (Bothriochloa bladhii) for 67 to 70 d. This was a RCBD with a factorial arrangement of 3 treatments by 3 BW blocks, with paddock and year as random effects. Heifers received one of three supplementation strategies: no cottonseed meal (CON), 454 g/animal of CSM daily (CSM1), or 908 g/animal of CSM every other day (CSM2). Initial and final shrunk BW were measured; ADG and percent of BW gained were calculated. Ultrasound of initial and final longissimus muscle area (LMA), backfat (BF), and intramuscular fat (IMF) were measured; percent gained was calculated, respectively. There were no treatment by block interactions for any measured variable. Heifers receiving CSM1 and CSM2 had greater final BW than heifers receiving CON (317 and 320.8 vs 302.6 kg, respectively; (P = 0.01). Likewise, percent of BW gained was greater (P = 0.02) for CSM1 and CSM2 supplemented heifers compared with CON heifers (19.4 and 20.2 vs 14.6%, respectively). The ADG of CSM1 and CSM2 supplemented heifers was greater (P = 0.01) than CON (0.74 and 0.78 vs 0.54 kg/d, respectively). Treatment did not affect the percent of BF (P = 0.24) or IMF gained (P = 0.39). Heifers receiving CSM1 and CSM2 tended to gain proportionally more LMA than heifers receiving CON (13.58 and 13.77 % vs 7.24%, respectively; P = 0.07). As anticipated, BW block affected final BW (P < 0.001) and percent BW gained (P = 0.02), as well as percent LMA gained (P = 0.02). In conclusion, CSM supplementation significantly affected growth performance of heifers grazing late summer WW-B. Dahl Bluestem forage versus no supplementation. In addition, there was no difference in growth performance between heifers receiving 454 g/d of CSM supplementation or 908 g/animal every other day, indicating flexibility for feeding strategy. [ABSTRACT FROM AUTHOR]

Despite the regular use of feed-grade macrolide-antibiotics, bovine liver abscesses persist, representing a financial burden to pre- and post-mortem sectors of the beef industry. An immunoglobulin-Y (IGY) additive developed to target Fusobacterium necrophorum and Trueperella pyogenes, was evaluated for the control of liver abscesses. Research is needed for the impact of liver abscess severity as well as abscess duration on steer performance and carcass characteristics. Holstein steers (n = 64; initial body weight (BW) = 372.5 ± 2.41 kg) consuming a finishing diet for 188 d were used in a completely randomized design where treatments included: TYL (tylosin phosphate 90 mg/d; n = 32) or IGY (2.5 g/d; n = 32) and steer was the experimental unit. Feed intake was recorded daily while BW and liver ultrasound outcome (normal or abnormal) was recorded every 28 d until slaughter to estimate duration of abscess presence (DUR). Continuous variables of animal growth performance and carcass characteristics were analyzed using the MIXED procedure of SAS. Categorical quality grade and liver data were analyzed using the GLIMMIX procedure of SAS. Treatment did not affect live or carcass-adjusted growth performance (P ≥ 0.131). However, steers fed TYL had greater (P = 0.042) empty body fat (EBF) % and a greater proportion of carcasses grading premium choice than steers fed IGY (P = 0.030). Treatment did not affect prevalence of abscessed livers, abscess severity or estimated abscess duration (P ≥ 0.213) but datasets with greater experimental units are needed to substantiate this outcome. Increasing abscess severity tended (P ≤ 0.10) to linearly reduce carcass-adjusted gain to feed (G:F), fat thickness, and EBF. Carcass dressing % was only affected by severe (A+ and A+AD) abscess scores (P = 0.010). Carcass-adjusted final BW, average daily gain, G:F, and hot carcass weight was decreased only when the estimated DUR was ≥ 140 d (P ≤ 0.05). Carcass dressing %, however, was linearly affected by estimated liver abscess DUR (P ≤ 0.005), regardless of abscess severity. Preliminary evidence suggests that measuring the duration of liver abscess affliction during the feeding period may also give insight to the degree of performance reduction. [ABSTRACT FROM AUTHOR]

The global pandemic forced many college courses into on-line modality and animal science (ANSC) departments were greatly affected by this change. The success of student content mastery was questioned. Animal science laboratory time may not be effectively replicated on-line but what about courses with no lab? Previous data in non-ANSC disciplines have indicated that student centered on-line learning can be just as effective as face-to-face courses regarding content mastery. It was hypothesized that to help meet the needs of a growing student population, some ANSC courses could increase their enrollment by offering on-line sections in conjunction with face-to-face modalities. However, a retrospective analysis of modality differences would need to be evaluated to determine equitability of student opportunities and outcomes between online and face-to-face sections of an ANSC course. Therefore, the objective was to critically evaluate the student content mastery of a core ANSC course offered both on-line and face-to-face across several terms. The Principles of Nutrition course at Texas Tech University, a non-lab associated junior-level core ANSC course, was selected for analysis. Course content exams and instructor of record were not changed for 9 semesters (Fall, Spring, and Summer) beginning in the Spring of 2019 and ending in Fall of 2022. Spring 2020 data were excluded. Students were filtered for drops, failures, and upper-class status to include 629 data points across 5 on-line sections (n = 225) and 5 face-to-face sections (n = 404). Content mastery was interpreted and measured as the mean percentage of four regular exams for each term. Content mastery was analyzed in a RCBD where modality was a fixed factor, major was block (ANSC or non-ANSC), and term was a random effect. Mean course mastery was 85.4 ± 9.1 %. There was no interaction of modality or major (P = 0.28). Modality did not affect student content mastery of the course (P = 0.45). Block was significant where ANSC majors had less (P = 0.03) content mastery than non-ANSC majors (85.1 vs. 87.4%, respectively), although still within the same letter grade of B. These results are consistent with those of other disciplines; interpreted to mean that on-line sections of non-lab associated ANSC courses may be an equitable option for ANSC students. In addition, on-line modality may be a preferred option for non-ANSC majors. An acknowledged limitation of these data set is the single course analysis and further research is needed to explore opportunities in other ANSC courses. Still these outcomes may aid in decision making when departmental classroom space is limited. In conclusion, the results of this analysis indicate that ANSC departments may prioritize their ANSC students in face-to-face modalities without negative consequences to non-ANSC majors who enroll in on-line sections. [ABSTRACT FROM AUTHOR]

Nutritive quality of perennial warm-season grasses during summer may limit the DMI of growing calves due to low protein and increased NDF content. Cottonseed meal (CSM) supplementation may improve forage utilization by increasing rumen degradable protein, but research in calves is limited. It was hypothesized that supplementation of CSM to heifers grazing mature forage would have improved performance due to greater forage DMI and fiber digestibility. Objectives were to compare the effects of CSM supplementation on calf gain performance, estimated forage intake, and in vitro true digestibility (IVTD) and neutral detergent digestibility (IVNDFD) of low-quality, warm-season forage. Angus heifers (n = 18) weighing 232.7 ± 12.6 kg were blocked by BW (light, medium, and heavy) and allocated to 6 paddocks (1.64 ha) of W.W. B-Dahl Bluestem (Bothriochloa bladhii) for 67 d. Heifers were supplemented daily with a mineral mix and either no cottonseed meal (CON) or 454 g/animal of CSM (CSM1) in a RCBD with a 2×3 factorial arrangement of treatments and BW blocks, respectively. Initial and final shrunk BW was measured to calculate total gain, ADG, and percent of BW gained. Forage samples were collected weekly and composited into 3 periods for chemical analysis and in vitro incubations. Forage DMI was estimated using a double sampling technique for each paddock within period. Forage IVTD and IVNDFD were analyzed using batch fermentation with and without CSM in a CRD (2 treatments by 3 periods). Mean forage CP during periods 1 and 2 were 5.75% and increased to 10.3% in period 3 (P < 0.01). Forage NDF content increased over time (64.1 vs. 69.3%; P < 0.01) and estimated forage DMI of heifers tended (P = 0.07) to decrease from 2.9 to 2.1% of BW. Treatment did not affect estimated forage DMI (P = 0.40). Heifers receiving CSM1 gained 28.3% more BW than heifers receiving CON (47.27 vs. 36.82 kg, respectively; P = 0.02). Percent of BW gained was greater for heifers receiving CSM1 than CON (16.9 vs. 13.8% of initial BW, respectively, P = 0.029). There were no treatment by period interactions on IVTD or IVNDFD. The IVTD of forage from period 1 was greater than periods 2 and 3 (49.9 vs. 47.1 and 46.6%, respectively; P = 0.005). The IVTD of forage incubated with CSM tended (P = 0.06) to be greater than forage without CSM (52.1% vs. 47.8%, respectively). The IVNDFD was not affected by period but tended to be greater with CSM inclusion (P = 0.09) relative to CON (24.83% vs. 18.95%, respectively). In conclusion, 454 g/d of CSM supplemented to heifers grazing latesummer W. W. B-Dahl Bluestem forage likely provided sufficient protein to alter ruminal fiber digestibility, without affecting forage intake, and had measurable effects on gain. [ABSTRACT FROM AUTHOR]

Summer stocker calves grazing perennial warm-season grasses may benefit from protein supplementation due to the low protein content typically observed in these forages. Cottonseed meal (CSM) is an excellent protein supplement that is readily available in the south and is competitively priced per unit of protein in early summer. However, research regarding the effects of CSM supplementation level and frequency on calf gain and composition of gain is limited. It was hypothesized that supplementing CSM to grazing heifers would improve ADG and perhaps alter composition of gain when compared with non-supplemented heifers. Objectives for this experiment were to 1) compare gain and composition of gain between calves supplemented with CSM to non-supplemented calves, and 2) compare the effect of daily vs. alternating days of CSM supplementation. A total of 27 commercial Angus beef heifers weighing 234.1 ± 4.18 kg were blocked by BW (light, medium, and heavy) and allocated to 9 paddocks of W.W. B-Dahl Bluestem (Bothriochloa bladhii) for 67 d. The experimental was designed as a RCBD with 3×3 factorial arrangement of 3 treatments and 3 weight blocks. Heifers were supplemented daily with a mineral mix and either no cottonseed meal (CON), 454 g/animal of CSM daily (CSM1), or 909 g/animal of CSM every other day (CSM2). Initial and final shrunk BW was measured, and total gain, ADG, and percent of BW gained were calculated. Ultrasound of initial and final longissimus muscle area (LMA), backfat (BF), and intramuscular fat (IMF) were measured. There were no treatment by block interactions for any measured variable. Treatment significantly affected total gain and ADG (P = 0.0156), as well as percent of BW gain (P = 0.029). Heifers receiving CSM1 treatment gained 28.3% more total BW than heifers receiving CON (47.27 vs. 36.82 kg, respectively) and CSM2 was intermediate (42.73 kg). Likewise, percent of BW gained was greatest for CSM1 and least for CON (16.9 vs.3.8% of initial BW), with CSM2 not differing (15.5% of initial BW). Treatment did not affect the composition of gain (P = 0.190); however, block tended (P = 0.0812) to affect LMA % gain, with light heifers being greater than medium and heavy heifers (12.00% vs. 7.35% and 5.09% increase, respectively). As expected, heifers grazing late summer W.W. B-Dahl Bluestem forage who received 454 g of CSM daily had significantly greater ADG than heifers not receiving CSM. Heifers receiving 909 g of CSM every other day tended to gain more than heifers not receiving CSM, but replication of this experiment is needed for validation of this specific supplementation strategy. In conclusion, supplementation of CSM to calves grazing low protein summer forage within a limited period may have positive measurable effects on gain. [ABSTRACT FROM AUTHOR]

The effects of a nutritional packet containing a direct-fed microbial combined with vitamins/electrolytes offered to beef steers in a calf-fed system on apparent total tract nutrient digestibility were evaluated. Angus crossbred steer-calves (n = 60; BW = 234 ± 4 kg) were assigned to a randomized complete block design (block = body weight; steer = experimental unit) and stratified into 2 treatments: a) control (no packet, finely-ground corn carrier only); and b) 30 g of DM/animal-daily of a nutritional packet [liveyeast (Saccharomyces cerevisiae; 8.7 Log CFU/g), Vitamin C (5.4 g/kg of Ascorbic acid), Vitamin B1 (13.33 g/kg of Thiamine hydrochloride), and electrolytes of NaCl (80 g/kg) and KCl (80 g/kg)]. Animals were individually offered [electronic feed-bunks (Smart-Feed/C-Lock Inc.)] a steamflaked corn-based finishing diet ad libitum, once daily for 233 d. Treatments were offered during the first (phase-1) and last (phase-2) 60 d on feed. At the conclusion of each phase, feed samples were collected once daily (1400 h), while fecal samples twice daily (0700 and 1700 h) from each steer during 4 consecutive days. Fecal and feed sample composites were dehydrated (55oC), ground (1 mm), and analyzed to assess DM, OM, NDF, ADF, and hemicellulose. The 288-h indigestible NDF was used as dietary internal marker to estimate fecal output and used to calculate nutrient digestibility. Data were analyzed using the GLIMMIX procedure of SAS. Intake of DM, OM, and fiber components during both digestibility trials were not affected (P = 0.56) by treatments. Steers offered the nutritional packet had increased (P < 0.01) apparent total tract digestibility of DM, OM, NDF, ADF, and hemicellulose by at least 2.4, 2.4, 8.3, 10, and 7.5%, respectively, in both digestibility phases. Superior nutrient digestibility without affecting nutrient intake may justify a potential enhanced carcass energy deposition. [ABSTRACT FROM AUTHOR]

The effects of a nutritional packet offered to beef yearling-steers during the feedlot-finishing phase on feeding behavior were evaluated. Crossbred-Angus steers (n = 30; initial BW = 542 ± 8 kg) were assigned to pens (15 steers/pen; animal = experimental unit) in a randomized complete block design. Steers were offered a steam-flaked corn-based finishing diet ad libitum, and treatments as follows: 1) control and 2) 30 g/steer-daily (DM-basis) of a nutritional packet (live yeast [Saccharomyces cerevisiae; 8.7 Log CFU/g], vitamin C [5.4 g/kg], vitamin B1 [13.33 g/kg], NaCl [80 g/kg], and KCl [80 g/kg]). Ground corn was used as a carrier and included at 1% of diet DM. Orts were subtracted from the dietary DM offered to calculate DM intake. Feeding behavior (meal frequency, meal size, bunk visit duration, and meal criterion) were continuously recorded using the Smartfeed system (individual animals). Three periods during the last 60 days before cattle harvest were assessed: 1) d7-11; 2) d28 -32; and 3) d49-53. Periods were used to compute meal criteria for each animal using the Meal Criterion Calculation (v. 1.9) software. Data were analyzed using the GLIMMIX procedure of SAS. No treatment × period interactions were observed (P ≥ 0.32) for meal frequency, duration (min/meal), and intake (kg/meal). Steers offered the nutritional packet had greater overall meal duration during periods 1 and 3 (75 and 77 min/d; P < 0.01), but did not differ (68 min/d; P = 0.09) for period 2 (Control AVR = 55 min/d). Steers offered the nutritional packet had greater (P ≤ 0.01) meal frequency (20 vs. 16 meals/d), while individual meal duration (3.85 min/meal) and meal intake (0.46 kg/meal) were not affected by treatments (P > 0.86). Improved meal frequency and overall time spent eating, without affecting intake, may induce a more desirable daily distribution of nutrients. [ABSTRACT FROM AUTHOR]

The effects of a nutritional packet containing a direct-fed microbial combined with vitamins/electrolytes offered at the beginning and end of the finishing phase to beef steers in a calf-fed system on feeding behavior were evaluated. Angus crossbred steer-calves (n = 18; BW = 234 ± 4 kg) were assigned to a randomized complete block design (block = body weight; steer = experimental unit) and stratified into two treatments: a) control (no packet, finely-ground corn carrier only); and b) 30 g of DM/animal-daily of a nutritional packet [live-yeast (Saccharomyces cerevisiae; 8.7 Log CFU/g), vitamin C (5.4 g/kg of ascorbic acid), vitamin B1 (13.33 g/kg of thiamine hydrochloride), and electrolytes of NaCl (80 g/kg) and KCl (80 g/kg)]. Animals were individually offered [electronic feed-bunks (Smart-Feed/C-Lock Inc.)] a steam-flaked corn-based finishing diet ad libitum once daily for 233 d, while treatments were offered during the first (phase-1) and last 60 d (phase-2) on feed only. Feeding behavior activities were assessed in min/d by using CowManagerTM ear tag sensors. Data were analyzed using the GLIMMIX procedure of SAS. There was no treatment × phase interactions (P ≥ 0.15), except that steers receiving the nutritional packet tended (P = 0.10) to spend more time (6 vs. 9 min/kg) eating digestible DM during phase-2 only. Regardless of phase, steers consuming the nutritional packet spent more time (P = 0.04) eating per kg of hemicellulose. Regardless of treatment, a decreased rumination (P ≤ 0.03) and chewing (P ≤ 0.01) activity-variables were observed for the phase-2 compared to phase-1. Steers receiving the nutritional packet exhibited superior time spent on eating activities, especially during the final 60 d before slaughter, and fiber seems to be the major driver inducing such effect. Towards the end of the finishing phase, cattle reduced rumination and chewing compared to the arrival phase. [ABSTRACT FROM AUTHOR]

The effects of a nutritional packet containing a direct-fed microbial combined with vitamins/electrolytes offered to beef steers in a calf-fed system on growth performance and carcass characteristics were evaluated. Angus crossbred steer-calves (n = 60; BW = 234 ± 4 kg) were assigned to a randomized complete block design (block = body weight; steer = experimental unit) and stratified into two treatments: a) control (no packet, finely-ground corn carrier only); and b) 30 g of DM/animal-daily of a nutritional packet [live-yeast (Saccharomyces cerevisiae; 8.7 Log CFU/g), Vitamin C (5.4 g/kg of Ascorbic acid), Vitamin B1 (13.33 g/kg of Thiamine hydrochloride), and electrolytes of sodium chloride (80 g/kg) and potassium chloride (80 g/kg)]. Animals were individually offered [electronic feed-bunks (Smart-Feed/C-Lock Inc.)] a steam-flaked corn-based finishing diet ad libitum, once daily for 233 d. Treatments were offered during the first (phase-1) and last (phase-2) 60 d on feed. Body weight measurements were taken every 30 d before feeding. Data were analyzed using the GLIMMIX procedure of SAS. Steers offered the nutritional packet had 14% less (P < 0.01) intake and 18% greater gain efficiency during the initial 30-d on feed, while such advantage did not (P = 0.26) persist when accounting for the initial 60 d for either variable. Overall intake (d0 to d233) was 6% greater (P = 0.02), while carcass-adjusted ADG (1.61 vs. 1.56), and carcass-adjusted gain efficiency (0.198 vs. 0.204) were unaffected (P = 0.44) compared with control, respectively. Dressing percent of steers offered the packet was 1 percentage-unit greater (P = 0.02), while other carcass variables were unaffected (P = 0.33). Calffed steers seem to benefit from such nutritional packet during the initial 30 d after feedlot arrival, while both superior intake and dressing percentage appears to last until cattle harvest. [ABSTRACT FROM AUTHOR]