Performance Of Beef Calves Research Articles

PSVIII-9 Effects of growth implants and timing of vaccination on calf immunity and growth performance

Abstract This study assessed calf growth performance and blood parameters of beef calves under different growth implants and timing of vaccination protocols. Crossbreed beef calves (n = 59) were stratified by birth body weight (BW) and age (41 ± 5.2 kg of BW and 70 ± 8 d of age) and randomly assigned in a split-plot design with implant strategy as the main plot and timing of vaccination as the subplot. The main plot (treatment) consisted of 3 implant strategies: 1) Synovex C (SC; n = 20; 100 mg progesterone/10 mg estradiol benzoate, or 2) Synovex One Grower (SG; n = 19; 150 mg trenbolone acetate and 21 mg estradiol benzoate; or 3) no implant (CON; n = 20). Subplot treatments were the timing of vaccination booster against bovine respiratory disease pathogens on 1) weaning (WV; n = 29) or 2) 7-d post-weaning (PWV; n = 30). Cow-calf pairs were treated alike in a single pasture during the pre-weaning phase, receiving the same vaccine (Bovi-Shield Gold One Shot and Ultrabac 7) on d 0 (implantation day) and booster time (WV or PWV). After weaning (approximately 187 d of age), calves were allocated in a single pen receiving ad libitum hay until d 60 post-weaning. Body weight and blood were collected on d 0, weaning, d 0 and 28 relative to vaccination booster, and d 60 post-weaning. Blood was collected to determine insulin-like growth factor (IGF-1), cortisol, and leptin concentrations and to perform a complete blood cell count. WV calves had decreased cortisol concentrations on booster day and 28 d post-vaccine (P = 0.01). Regardless of implant treatment, calves tended to have decreased IGF-1 concentrations 28-d post-vaccine booster (P = 0.09). An effect of treatment (P < 0.01) was detected for lymphocyte counts, with CON having greater concentrations vs. SG and SC calves. A treatment × timing of vaccination (P < 0.01) interaction was detected for monocyte counts, where SG-PWV calves had the greatest concentrations. A treatment effect (P < 0.02) was observed for eosinophil percentage, where SG had reduced percentages than CON, while SC was intermediate. An effect of treatment was detected for leptin (P < 0.01), with SG calves having the least, CON being intermediate, and SC the greatest concentrations. From d 0 to 60 d post-weaning, SG tended to have greater ADG (P ≤ 0.07) compared with CON, while SC was intermediate. On d 28 and d 35 post-weaning, calves implanted with SG were heavier (P ≤ 0.04) than the CON but not than SC. In summary, this study demonstrates that growth implants and timing of vaccination significantly affect both physiological parameters and growth performance in beef calves. Implanting calves with Synovex One Grower resulted in improved growth performance.

PSII-5 Effect of short-term feeding of hemp (Cannabis sativa) on stress biomarkers in weaned beef calves

Abstract Hemp research is growing rapidly due to its health benefits for animals; however, there is little information on its effects on stress. The objective of this study was to determine the effects of hemp supplementation on stress biomarkers in beef calves during weaning. Calves (n = 12) were completely randomized into Control (CC: received commercial concentrates before and after weaning), Treatment 1 (CH: received commercial concentrates before weaning and 25 g of hemp diet after weaning), Treatment 2 (HC: received 25 g hemp diet before weaning and commercial concentrates after weaning) and Treatment 3 (HH: received 25 g hemp diet before and after weaning). The study lasted for 28 d; blood samples were collected at 7-d intervals for enzyme-linked immunosorbent assay. Plasma was analyzed for heat shock protein 90, cortisol, haptoglobin, total antioxidant capacity, and glutathione peroxidase. There was treatment x time interaction in cortisol concentrations, with the (CH) group showing the greatest concentration of cortisol (124.23 ng/mL) in wk 3. There was no significant (P = 0.0675) difference in total antioxidant capacity. There was a treatment x time interaction (P = 0.0009) in glutathione peroxidase concentrations, with the (HH) group showing the greatest concentration of glutathione peroxidase of 46.83 ng/mL in wk 2 and 47.57ng/mL in wk 3. There was no significant (P < 0.05) difference in heat shock protein and haptoglobin. We concluded that hemp supplementation could reduce weaning stress in beef cattle, thereby improving the productivity and performance of beef calves

363 Effects of supplementation of vitamin B complex on the performance of beef calves during a 42-d preconditioning program

Abstract The objective of this study was to evaluate the effects of supplementation of vitamin B complex on post-weaning performance of beef calves. The study was conducted during fall of 2023 at Eastern Oregon Agriculture Research Center (EOARC; Burns, OR). At weaning (d 0), 63 calves [Angus × Hereford; body weight (BW) = 252 ± 3.6 kg] were randomly assigned to 1 of 3 treatments: 1) Control, 2) VitB1, or 3) VitB2. Calves assigned to Control treatment served as a negative control and were not supplemented with vitamin B complex. Calves assigned to treatment VitB1 were supplemented at 1g/calf daily, while calves assigned to VitB2 treatment were supplemented at 2g/calf daily of vitamin B complex during the 42 d of preconditioning. Upon weaning processing, calves were allocated to 21 pens (3 calves/pen) and treatments were allocated to each pen (7 pens/treatment). Vitamin B complex [Vivalto, pantothenic acid (B5; 40,000 mg/kg), pyridoxine (B6; 20,000 mg/kg), folic acid (B9; 3,200 mg/kg), biotin (B7; 3,200,000 mcg/kg), cobalamin (B12; 320,000 mcg/kg); Selko USA, Indianapolis, IN] supplementation was offered at pen level beginning on d 1 and until the end of the preconditioning phase (d 42). Vitamin B complex was offered to calves assigned to vitamin B complex treatment mixed with 1.3 kg of dried distiller’s grains. Additionally, calves had free access to chopped alfalfa-grass hay mix and whole corn. Pen intake was recorded daily. On d 0, BW and blood samples were collected from all calves. Additional blood and BW were collected on d 1, 3, 7, 14, 21, 42 post-weaning. Body weights were used to calculate calf average daily gain (ADG) and blood samples were assayed for acute phase proteins (ceruloplasmin and haptoglobin). Additional blood samples will be analyzed for cortisol and vitamin B concentrations. Variables were analyzed considering pen as the experimental unit and pen(treatment) as a random effect. Blood variables were evaluated as repeated measures and effects of treatment, day, and treatment the interactions were analyzed with the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC). Significance was set at P ≤ 0.05. No treatment effects (P = 0.98) were observed for final BW (283, 283, and 284 kg respectively for Control, Vit1, and Vit2) or for ADG (P = 0.53; 0.735, 0.795, and 0.747 kg/d respectively for Control, Vit1, and Vit2). Similarly, no treatment effects were observed for the acute phase proteins analyzed, ceruloplasmin (P = 0.66; 27, 30, and 33 µg/dL respectively for Control, Vit1, and Vit2) and haptoglobin (P = 0.41; 0.55, 0.62, and 0.59 mg/mL, respectively for Control, Vit1, and Vit2). Supplementation of vitamin B complex to beef calves post-weaning does not seem to affect calf performance, regardless of the level of supplementation.

PSVI-23 Effects of Creep-Feeding Supplementation on Growth Performance of Nellore Calves and Milk Yield of Dams

Abstract The study aimed to evaluate the effect of creep-feeding on growth performance of beef calves and milk yield of dams, during nursing phase. The experiment lasted 170 days, from December/2021 to May/2022, the calves were born in September/2021 and creep-feeding supplementation started from approximately 70 days of life until weaning. The experimental design used was a randomized block [blocked by body weight (BW) of calves]. The experimental units were the paddocks (8 units per treatment, and ten replicates per paddock), totalling 156 pairs cow/calf (86 pairs of male calves and 70 pairs of female calves). The treatments consisted of creep-feeding or not creep-feeding the calves: control treatment (CONT; mineral supplement ad libitum) and creep-feeding treatment (CREEP; energetic protein supplement; 5 g/kg of BW· animal-1· /day-1). There was mineral supplement ad libitum for all the dams. The pairs cow/calf were kept in an area of Urochloa brizantha cv. Marandu. The data were analyzed using the SAS PROC MIXED. Male calves subjected to CONT showed less BW (-15 kg) at weaning and decreased average daily gain (ADG; -100g/day) until weaning (P < 0.01; Figure 1), while female calves showed no difference in BW and ADG (P > 0.12; Figure 2). The dams did not show difference in milk yield until weaning (P > 0.27) for male and female calves (Figure 3). This difference in results related to gender is explained by the fact that there are differences in the performance of males and females, mainly due to hormonal issues. Usually, females are born lighter than males and tend to have decreased performance throughout the whole production cycle. For milk yield and performance of dams, our results agree with what is found in the literature. There are some studies which also evaluated milk production of dams when the offspring were creep-fed, and found similar milk yield for those whose offspring received supplement in relation to those who did not receive it. This is likely because calves prefer milk, supplement, and forage, in that order, so it seems unlikely that calves would replace milk with supplements. And these results show us that the difference in the BW at weaning of males was caused by the creep-feeding supplementation.

152 Impact of Early Life Nutrition and Supplementation of a Yeast Derived Product in Growth and Development of Beef Calves

Abstract The objective of this experiment was to evaluate the impact of a yeast-derived product (Celmanax; Church & Dwight Co., Inc.; Princeton, NJ) supplementation on performance of beef calves during the backgrounding phase. A total of 44 male castrated beef calves [249 ± 31 kg body weight (BW), 296 ±8 days of age], were stratified by BW and randomly assigned to one of two treatments: supplementation of kg-1calf-1d of corn gluten feed (Control; n = 22); or supplementation of kg∙animal-1∙day-1 of corn gluten feed and 14 g∙animal-1∙day-1 (as fed-basis) of a yeast derived product (Treatment, CEL; n = 22). Steer calves received their treatment for 30 days, using an automated feeding system (SmartFeed PRO, C-Lock Inc., Rapid City, SD). Four automated feeders allowed each group to have access to their specific diet, while being managed as a single group during the total duration of the experiment, and daily individual animal supplement intake were recorded. Before the beginning of the experimental period, calves were trained to use the automated feeding system for 30 days. Steer calves also had ad libitum access to a fescue pasture and grass hay. Body weight was measured every 14 days using a livestock scale. At day 30, calves were loaded into a commercial livestock trailer and transported to a feedlot for a total of 6 hours. Feed samples were collected every week, dried to measure dry matter content, and kept for further nutritional composition chemical analyses. Individual daily intake of supplement was similar between treatments (0.82 ± 0.06 and 0.9 ± 0.07 kg/d for CEL and Control, respectively; P = 0.36). Average daily gain (ADG) showed no difference between treatments (0.57 ± 0.05 and 0.61 ± 0.05 kg/d for CEL and Control, respectively; P = 0.59), reaching the same final body weight (256 ± 6.73 kg for CEL and Control; P = 0.98). Body weight loss during transportation (12.6 ± 0.87 kg and 12.4 ± 0.85 kg for CEL and Control, respectively; P = 0.9) was not different between treatments, reaching normal values for that length of transportation. In conclusion, supplementation of a yeast-derived product during 30 days before transportation did not cause any changes in performance of backgrounded beef steer calves.

190 Assessment of Weaning Management on Growth Performance and Health in Southeastern Beef Calves

Abstract The beef calf weaning period is a time of transition in the cow-calf production cycle and can be one of the most stressful stages in the life of a beef calf. This transition can have a major impact on both calf short- and long-term health, growth performance and economic returns. There are several different weaning management strategies cattle producers can use in this transition period. The objective of this study was to assess the effects of weaning management practices on beef calf performance and health before backgrounding. A two-year study was conducted using 427 steer calves (216 year 1, average BW 297 kg; 213 year 2, average BW 291 kg) from three Auburn University research farms were randomly assigned based on weaning weight to one of three different weaning method groups for a 14-day observation period: fenceline, nose-flap, or abrupt weaning. On day 0, all calves assigned to the abrupt weaning group traveled 3 hours to one central location. Calves in the fenceline and nose-flap groups traveled to the same location on day 14 of study. Calves were weighed on day 0, day 14 and 24 hours following any travel event. Blood samples were also collected to determine haptoglobin concentrations surrounding the travels events and blood titers following vaccinations. In both years of the study, fenceline weaned calves had the greatest average daily gain at 1.08 kg/d (P < 0.0001) and abruptly weaned calves had the least average daily gain, losing 0.15 kg/d during the 14-d observation period. In Year 1, steers had a significantly greater (P < 0.0001) gain across all treatments than calves in Year 2, with Year 1 calves gaining 7.72 kg more during the weaning period than Year 2 calves. Over both years of the study, fenceline weaned calves gained more (P =0.0008) than both nose-flap and abruptly weaned calves. In Year, abruptly weaned calves had greater blood concentrations of haptoglobin (0.084mg/mL; P < 0.0001) than both the fenceline and noseflap weaned calves (0.023mg/mL; 0.020mg/mL). This data demonstrates how weaning management strategies may influence calf growth performance and the transition into the post-weaning period.

Short Communication: Performance of steers fed on pasture receiving different seeding rates of vetch in an integrated crop-livestock system

Aim of study: To evaluate the performance of beef calves fed black oat and Italian ryegrass pasture seeded with several different seeding rates (SR) of common vetch in a crop-livestock integrated system.Area of study: The experiment was carried out in Dois Vizinhos city, Paraná, Brazil.Material and methods: An area of 8.3 ha was used, which was divided into 11 paddocks, 0.75 ha each. Nellore calves (n = 22), 7 ± 2 months old and with initial body weight of 134 ± 27 kg were used for the tests. The experimental design was completely randomised. Vetch (Vicia sativa L., ‘Amethyst’) SR treatments included 0, 15, 30, and 45 kg ha-1, in a mixture with black oat (Avena strigosa Schreb. ‘IPR 61’ and Italian ryegrass (Lolium multiflorum Lam.) pastures.Main results: There was no effect of SR on pasture productivity parameters. The increase in vetch seed in the seed mixture resulted in an increase in crude protein and neutral detergent fibre, but decreased in vitro digestibility of vetch. However, these changes did not affect the nutritional value of the pasture. Vetch SR of 30 kg ha-1 or higher allowed greater share of the legume in the pasture, thereby enhancing greater individual animal performanceResearch highlights: Vetch SR of 30 kg ha-1 or higher allowed greater share of the legume in the pasture, thereby enhancing greater individual animal performance.

Measurement of transfer of colostral passive immunity in dairy calves

Measurement of transfer of colostral passive immunity in dairy calves

PSXII-12 The influence of long-term molybdenum supplementation (in drinking water or feed) on beef calf performance through weaning

Abstract Fifty-four multiparous beef cows were used to examine the effect of molybdenum (Mo) supplemented in drinking water or feed on offspring performance. Cows were blocked by body weight (BW) and age into one of 6 groups. Group were then randomly assigned to treatment. Treatments consisted of: 1) Control (no supplemental Mo or Cu), 2) Control+Cu (3 mg Cu/kg DM from CuSO4·5H2O added to the basal diet), 3) Control + 500 µg Mo/L from MoNa2O4·2H2O in drinking water (Mo 500-water), 4) Control + 1000 µg Mo/L of MoNa2O4·2H2O in drinking water (Mo 1000-water), 5) Mo 1000-water plus 3 mg Cu/kg DM from CuSO4·5H2O added to the basal diet (Mo 1000-water+Cu, and 6) Control plus 3 mg Mo/kg DM from MoNa2O4·2H2O added to the basal diet (3.0 Mo-diet). Cows were housed in dry lot pens (n = 3 cows/pen; 3 pens/treatment) and fed a low-quality grass hay diet (DM basis: 6.6% CP; 0.14% S, 6.2 mg Cu/kg, 2.3 mg Mo/kg) and a protein supplement (30% CP). Cows received their respective treatments beginning 60 d prior to breeding and remained on treatments until all calves were weaned at approximately 7 mo. of age. Calf birth weights were collected on the day of birth and all calves were weaned on the same day. Data were analyzed using a mixed effects model for a completely randomized block design. Birthweight, ADG, and 205d adjusted weaning weights were similar (P > 0.05) across treatments. These data indicate that Mo supplemented in the drinking water or the diet regardless of the inclusion of additional Cu did not impact calf performance through weaning.

9 Backgrounding system diet effects on performance of beef calves during transportation and feedyard adaptation

Abstract Nutritional management during the backgrounding phase may influence beef calf performance and ease-of-transition into the feedyard. The objective of this study was to evaluate effects of various diets on performance of calves during backgrounding, transportation, and arrival at a feedyard. In June 2019, 119 fall-born steers (n = 79, 266 ± 34 kg BW) and heifers (n = 40, 236 ± 26 kg BW) at E.V. Smith Research Center (Shorter, AL) were weaned and randomly assigned to one of four diets (3 pens per dietary treatment, 10 calves per pen): cool-season baleage (oats, annual ryegrass, and crimson clover; B), cool-season baleage and 1% BW of a commercial, high-energy grower supplement (BC), cool-season baleage and 1% BW dried distiller’s grains with solubles (DDGS; BD), or ‘Tifton 85’ bermudagrass hay and 1% BW DDGS (HD). After a 10-d acclimation period, calves began a 60-d backgrounding trial and were weighed at d 0, d 30, and d 60. There was a diet × period interaction (P = 0.0017) such that ADG decreased from 0.38 to 0.19 kg/d for calves on B, while in treatments with supplementation, calves maintained gains of 0.67 kg/d or greater into the second, 30-d period. After the end of the backgrounding trial, calves were transported to Hy-Plains Feedyard in Montezuma, KS. Calves were weighed prior to transport, immediately after transport, after 24 h rest, and 7 d on feed. Immediately after tranport, B calves had the greatest shrink (12.8%, P < 0.001) compared to calves that had received supplemental feed (10.1%). After 7 d, B calves regained the lowest percentage of pre-shipping BW (93.5% weight, P < 0.01) compared to calves that had received supplemental feed (96.3% weight). These data suggest that supplementing forage-based diets may provide a performance advantage during the preconditioning phase and better prepare calves for transportation and the transition into the feedyard.

120 Performance Effects on Weaned Calves using 3 Weaning Strategies and Nutritional Supplementation

Abstract The objective of this study was to compare nutritional and management strategies on performance of beef calves at weaning. Forty crossbred beef calves were assigned to receive either nutritional supplementation (Drench) 3 wks prior to weaning and again at weaning or nothing (Cntrl). In addition, calves were assigned 1 of 3 weaning treatments: 1) abrupt weaning with complete separation (Abrupt); 2) 4d fence line weaning with cows allowed to interact with calves through a fence for 4 d before removal (4Fence); and 3) 7 d fence line weaning with cows allowed to interact with calves through a fence for 7 d before removal (7Fence). Calves were blocked by sex and BW. Nutritional supplementation consisted of an oral drench (5cc/100 lbs. BW; Cellarator Turbo Drench; ADM Animal Nutrition; Quincy, IL). Calves were weighed at weaning, 7 d after, and 85 d after weaning. At weaning, average age of calves was 213 ± 19 d and average weight 224 ± 30 kg. Average final weight of calves was 279 ± 33 kg. Weight differences between weaning and 7 d after weaning and weaning and 85 d after weaning were analyzed using Proc Mixed with nutritional supplementation, sex, and weaning duration as fixed variables. Calves receiving Drench gained more (P < 0.05) 1 wk after weaning (7.9 vs. 3.7 kg, respectively). Weight gains 85 d after weaning were not different (P > 0.05) 7 d after weaning. Weight gain in calves assigned to 4Fence and 7Fence treatments were not different (P < 0.05) but gained more (P < 0.05) than Abrupt calves (8.5 vs. 7.6 vs. 1.2 kg, respectively). Weight gains 85 d after weaning were not different (P > 0.05) between weaning treatments. In conclusion, nutritional supplementation and fence-line weaning improved calf performance 1 wk after weaning but not after 3 mo.

Influence of organic chromium supplementation on the performance of beef calves undergoing weaning-related stress

ABSTRACT: Dietary chromium supplementation before, during, and after weaning was conducted to evaluate the hypothesis that chromium supplementation could reduce weaning-induced cortisol release in beef calves. We examined the effects of chromium supplementation in 150 crossbred calves (male and female) between five and six months of age. The calves were randomly divided by sex and breed into two equal homogeneous groups (n=75). One group was used as the control, and the other experimental group received supplementation with 0.9mg of chromium carbon-amino-phospho-chelate per 100kg BW. The chromium supplement was mixed with mineral salt for the consumption of 0.1% of BW, and the supplement was administered via creep feeding 60 days before and 60 days after forced weaning. Calves were weighed, and their blood and urine samples were obtained at four time-points: T0 (60 days before weaning), T1 (at weaning), T2 (48 hours after weaning), and T3 (60 days after weaning). Blood samples were used to determine chromium, cortisol, total protein, and albumin concentrations, and urine samples were used to determine urinary creatinine and chromium levels. Cumulative weight gain was higher in calves supplemented with chromium before weaning and during the experiment (P<0.05). In addition, weaning-related stress caused an increase in chromium excretion in the urine, and chromium supplementation reduced stress, which resulted in lower cortisol and total protein levels during weaning.

Desempenho de bezerros depois da inclusão de ureia de liberação lenta em suplemento proteico para bovinos

Objetivou-se avaliar a substituição do farelo de soja (FS) do suplemento proteico por ureia encapsulada (UE; Optigen®) sobre o desempenho de bezerros na época seca. Utilizou-se 60 bezerros Nelore, com peso corporal (PC) de 172,37 ± 19,93 kg, mantidos em pastagem de capim-marandu. Os tratamentos foram: 0% UE (100% FS e 0% UE); 25% UE (75% FS e 25% UE); 75% UE (25% FS e 75% UE); 100% UE (0% FS e 100% UE). O delineamento experimental foi o de blocos completos casualizados com três repetições. Não houve efeito do nível de substituição do FS por UE sobre o ganho médio diário (GMD) e PC. O GMD e o PC foram influenciados pelo período. Para o GMD o maior valor observado no último período (dia 112 a 140) e o menor no segundo período (dia 56 a 112). Houve um aumento do PC até o dia 56, que não se diferenciou do dia 112 e depois aumentou no dia 140. O consumo de suplemento foi reduzido pela inclusão de UE. Concluiu-se que em pastagens contendo lâmina verde, o FS pode ser substituído por UE sem que ocorra prejuízo ao desempenho produtivo de bezerros na época seca.

Comparison of effects of four weaning methods on health and performance of beef calves

Weaning of beef calves is a stressful event that negatively impacts health and performance. A variety of interventions have been proposed to reduce stress and improve gains following weaning. This study used 288 7- to 8-month-old calves from two separate locations, to examine four different weaning strategies, as well as the impact of shipment. Calves were blocked by weight and sex, and then randomly assigned to one of four treatments: abrupt weaning (AW), where calves were separated from the dam on day 0 (D0) and allowed no further contact with the dam; fence line (FL), where calves were weaned on D0 but had fence line contact with dams for 7 days; nose flap (NF), where on day -6 calves received a nose flap that interferes with suckling, then had the flap removed and were weaned from the dam on D0; and intermittent separation (SEP), where calves were removed from dams for 24-h intervals on day -13 and day -6, then weaned on D0, but allowed fence line contact with the dam for 7 days. Each treatment group was further divided into two subgroups, one of which was shipped early (D0 for AW, day 7 for others) or shipped later (day 28). Body weight and sickness were recorded for all groups. Results showed a negative impact on gain for early shipping compared to later shipping, and poorer gain in AW calves than most other treatments. Results of the analyses of morbidity were inconclusive. This study found that delayed shipment following FL weaning improves performance under common management conditions for the US cow–calf industry.

PSXIV-24 Immune function and growth performance in beef calves supplemented during backgrounding with live yeast and yeast cell wall in combination with supplemented dams

Abstract Live yeast and yeast cell wall products potentially improve health and performance in cattle during the stocker and feedlot phases. Therefore, the objective of this study was to investigate yeast-product supplementation during late gestation through 88 d of age, and(or) a 42-d backgrounding period on immune function and growth performance. Late gestation cows (n = 97) were assigned randomly to treatment: 1) supplement without yeast (CON) or 2) supplement with yeast products (YP). At weaning, calves from each dam treatment (CON or YP) were pooled by dam treatment and stratified based on BW, sex, dam parity, and sire and split into 8 pens within dam treatment. Pens were assigned randomly to 1 of 2 backgrounding treatments (CON or YP) such that a total of 4 pens/treatment existed. Treatments included: 1) dam YP, calf YP, 2) dam YP, calf CON, 3) dam CON, calf YP, and 4) dam CON, calf CON. Calves were fed 2 kg/d of grain and yeast (5 g/d) was provided in a top-dress (ground corn plus YP). Weaning weights (P = 0.99) and backgrounding ADG (P = 0.29) did not differ. Total ruminal VFA concentrations, sampled on d 0 and 42 post-weaning, were increased in calves from dams supplemented with YP (P = 0.04). There were no effects of treatment (P ≥ 0.32) on molar proportions of acetate and propionate. Haptoglobin (P ≥ 0.49) and neutrophil:lymphocyte ratio (P ≥ 0.46) were not influenced by treatment but were affected by day (P < 0.01). While there was no effect of YP (P = 0.73) on BVD titers, there was a day effect (P < 0.01) where titers were greatest on d 28 and least on d 0. Post-weaning yeast supplementation in combination with dam supplementation did not improve calf immune function or performance during a 42-d backgrounding period.

144 Monensin effects on beef calves receiving limited creep-feeding supplementation

Abstract Monensin is a feed additive used to increase performance of beef cattle; however, the effects on cattle grazing warm-season perennial forages with limited levels of concentrate are inconsistent. The objective of this study was to test the effects of monensin on performance of beef calves receiving limited creep-feeding supplementation. The experiment was conducted in Ona, FL, from April to August (112 d) 2018. The creep-feeding supplementation level was 400 g of soybean meal/d. Calves were supplemented 3 days per week, Monday, Wednesday, and Friday, thus the daily supplementation level was multiplied by 7 d and divided by 3 feeding days. Treatments were monensin (20 g/kg of the expected DMI) or control (no monensin), distributed in a randomized complete block design with four replicates. Twenty four cow-calf pairs (415±29 and 162±35 kg, respectively) were randomly distributed in eight limpograss (Hemarthria altissima) pastures (experimental units; 1.0 ha/pasture; 3 cow-calf pairs/pasture). Pastures were grazed with a continuous and fixed stocking rate. There was no difference in herbage mass (mean = 2,250 kg/ha, P =0.52, SE = 120) and herbage allowance (HA, mean = 1.2 kg DM/kg LW, P = 0.52, SE = 0.04) between treatments. In addition, there was no effect of monensin on calf average daily gain (mean = 0.77 kg/d, P = 0.27, SE = 0.04), cow body condition score (BCS, mean = 5.1, P = 0.15, SE = 0.15), and calf coccidia infestation (mean = 0.18 log egg count, P = 0.98, SE = 0.08). Calves receiving monensin consumed a lesser (P < 0.01) proportion of the supplement than control in the first 13 h after supplementation (76 vs. 95%). Monensin was not effective to increase performance of beef calves receiving limited creep-feeding supplementation.

Effects of tillage method and planting date of wheat pasture on forage production and beef calf performance

ABSTRACT Objective This experiment was designed to determine the effect of wheat establishment method [conventional clean tillage (CT) vs. no-till (NT)] and planting date on forage and animal production over 3 yr. Materials and Methods No-till pastures (each 1.6 ha) were planted on 3 planting dates: early, August 15 (n = 8, ER); mid, September 1 (n = 8, MD); and late, September 15 (n = 8, LT). Clean-till pastures (each 1.6 ha) were established on MD (n = 3) and LT (n = 3) planting dates. Steers (n = 360, BW = 249 ± 24.7 kg) were placed on wheat pasture for the fall and winter grazing season and replaced with a new set of steers (n = 720, BW = 280 ± 44.9 kg) for spring grazing. Results and Discussion Although CT MD had the greatest (P ≤ 0.04) forage mass in November, ADG did not differ (P = 0.81) in the fall. Spring ADG of CT MD was least (P Implications and Applications Planting NT ER did not result in improved forage or animal production versus CT MD or NT MD. Clean tillage had advantages over NT if planting is delayed until mid-September, but performance in spring and total productivity were better for NT.

PSII-12 Effect of Maternal Supplementation with an Injectable Trace Mineral on Pre-Weaning Beef Calf Performance and Mineral Status.

PSII-12 Effect of Maternal Supplementation with an Injectable Trace Mineral on Pre-Weaning Beef Calf Performance and Mineral Status.

Effects of dietary protein level and rumen-protected pantothenate on nutrient digestibility, nitrogen balance, blood metabolites and growth performance in beef calves

Effects of dietary protein level and rumen-protected pantothenate on nutrient digestibility, nitrogen balance, blood metabolites and growth performance in beef calves

114 Establishing the Efficacy of Faecalibacterium Prausnitzii As a Probiotic to Enhance Pre-Weaning Health, Growth and Performance of Beef Calves.

114 Establishing the Efficacy of Faecalibacterium Prausnitzii As a Probiotic to Enhance Pre-Weaning Health, Growth and Performance of Beef Calves.