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The objective was to evaluate growth performance and carcass traits following transit of feedlot heifers sourced and finished in different geographical regions in the U.S. Yearling heifers [n = 190; initial body weight (BW) 483 and 425 kg for SD and TX sourced, respectively] were used in a 2×2 factorial arrangement of origin state (SD vs TX) and finishing state (SD vs TX). Heifers were allotted on d -1 into four treatments: sourced from SD and finished in SD (SD-SD), sourced from SD and finished in TX (SD-TX), sourced from TX and finished in SD (TX-SD), and sourced from TX and finished in TX (TX-TX). Heifers were weighed on d -1, 3, 15, 28, 56, 78 (TX-TX and SD-TX) and 90 (SDSD and TX-SD). On d 0, SD-TX and TX-SD heifers were shipped to the finishing location and weighed the following morning (d 1) to determine transportation shrink. To monitor transportation effects, vaginal temperature probes were inserted into all SD-TX and TX-SD heifers and a portion of SD-SD and TX-TX heifers on d -1 and removed on d 3. Clinical attitude scores (CAS) were recorded on d -1, 0, 1, 2 and 3 for indications of bovine respiratory disease symptoms. The GLIMMIX procedure of SAS was used to analyze growth performance and carcass measures with fixed effects of origin and finishing state. The MIXED procedure was used for CAS and temperature data with the same fixed effects and time as a repeated measure. Transported heifers had reduced temperatures (P < 0.05) during transit and post-transit compared with non-transported heifers. Temperatures of transported heifers increased (P < 0.05) during loading and unloading. On d 0, 1 and 3 there was a shift in the distribution of heifers that had a CAS score greater than 0 for TX-TX, SD-TX and TX-SD. Cattle endured high ambient temperatures (temperature humidity index value > 75) 54% and 18% of the feeding period for TX and SD finished heifers, respectively. All cumulative growth performance measures and carcass trait interactions were statistically significant (P < 0.05) besides initial BW, percent shrink of transported heifers, average daily gain, dressing percent, ribeye area and liver abscess severity, which were similar (P > 0.30). There was a shift in the distribution (P < 0.05) towards a greater proportion of Yield Grade 1 and Select carcasses for heifers fed in TX compared with those fed in SD, likely due to fewer days on feed. Overall, heifers transported to higher ambient temperatures had reduced dry matter intake, quality grades (QG) and limited growth recovery (45 kg lighter) compared with non-transported heifers. Heifers transported to lower ambient temperatures recovered growth and had improved QG at the same level of rib fat compared with non-transported heifers. [ABSTRACT FROM AUTHOR]

The objective of this research was to determine the influence manger space restriction had on program fed feedlot heifers during the growing phase. Charolais × Angus heifers [initial body weight (BW) = 329 ± 22.1 kg] were used in a 109-d backgrounding phase study. Heifers were received from a ranch in western South Dakota approximately 60 days before study initiation. Initial processing (53 days before study initiation) included individual BW measurement, application of a unique identification tag, vaccination against viral respiratory pathogens (Bovi-Shield Gold 5, Zoetis, Parsippany, NJ) and clostridial species (Ultrabac/Somubac 7, Zoetis), and administration of doramectin pour-on (Dectomax, Zoetis) for control of internal and external parasites. All heifers were administered 36 mg of zeranol (Ralgro, Merck Animal Health, Madison, NJ) at study initiation. Upon study initiation, heifers were assigned to 1 of 10 pens (n = 5 pens/treatment with 10 heifers/pen) in a randomized complete block design (blocked by location). Each pen was randomly assigned to 1 of 2 treatments: 20.3 cm (8IN) or 40.6 cm (16IN) of linear bunk space/heifer. Heifers were individually weighed on days 1, 14, 35, 63, 84 and 109. Heifers were programmed to gain 1.36 kg daily based on predictive equations for a medium frame steer calf set forth by the California Net Energy System. To calculate predictive values, a final BW of 575 kg was assumed to be the mature BW of the heifers and tabular net energy values of 2.05 NEm and 1.36 NEg from d 1 to 22, 2.00 NEm and 1.35 NEg from d 23 to 82, and 1.97 NEm and 1.32 NEg from d 83 to 109 were used, because of ingredient inventory changes. Data were analyzed using the GLIMMIX procedure of SAS 9.4 with manger space allocation as the fixed effect and block as the random effect. No differences (P > 0.35) were observed between 8IN or 16IN heifers for initial BW, final BW, average daily gain, dry matter intake, feed efficiency, variation in daily BW gain (within pen standard deviation) or applied energetic measures. No differences (P > 0.50) were observed between treatments for morbidity. Although not statistically analyzed, 8IN heifers appeared to have looser stools during the first two weeks compared with the 16IN heifers. These data suggest restricting manger space allocation from 40.6 cm to 20.3 cm did not negatively influence gain efficiency or the efficiency of dietary net energy utilization in heifers programmed fed a concentratebased diet to gain 1.36 kg daily. The use of tabular net energy values and required net energy of maintenance and retained energy equations are an effective means to program cattle to a desired daily rate of gain during the growing phase. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of calcium magnesium carbonate (CMC) and/or tylosin phosphate (TYL) supplementation on behavior, rumination activity, growth performance and carcass characteristics of yearling beef steers. Treatments were arranged in a 2 × 2 factorial including CMC and TYL. Beef steers (n = 156; 469 ± 18 kg) were randomly assigned to treatment pens (7 to 8 steers/pen) with pen (n = 20 pens total, 10 pens/main effect mean, and 5 pens/simple effect mean) as experimental unit. Cattle were transitioned from a 30% roughage diet to a 7% roughage finishing diet based on dry-rolled corn, dried distillers grains plus solubles, liquid supplement, and oat silage over the initial 20 d period. The CMC was included at 1.5% of the diet (DM basis) in replacement of dryrolled corn and TYL was provided at 90 mg·animal·d-1. Behavior and rumination activity were monitored during a 24 h period on d 42. Data was collected on a pen-basis, every 10 min from 0800 h to 0750 h the next day and included minutes spent drinking (DR), eating (EA), active (AC), ruminating (RU), and resting (RE). Cattle were shipped for harvest on d 105 to a commercial beef abattoir. Growth performance was calculated on a carcass-adjusted basis (HCW/0.625). Data were analyzed as a randomized complete block design with fixed effects of CMC, TYL, or their interaction; block was a random effect. An interaction was observed between CMC and TYL for time spent DR (P = 0.03) and RU (P = 0.01). Control steers ruminated 28% longer compared with CMC/-TYL steers (P = 0.05) and 20% longer than -CMC/TYL steers (P = 0.05). The main effect of CMC tended to increase time spent EA by 19.3% (P = 0.06). Dry matter intake was decreased (P = 0.02) by 4.57% when CMC was fed and increased by 1.96% when TYL was fed. However, no difference (P = 0.26) was observed for G:F or gain efficiency in either treatment. No differences (P = 0.28) were observed in any dietary net energy utilization outcomes in either main effect treatment. Carcass weight tended (P = 0.07) to be lighter with CMC supplementation compared with CON (432 vs 439 kg). Supplementation of TYL resulted in a 11.7% reduction (P = 0.04) in percentage of abscessed livers. No differences (P = 0.12) were observed in DP, marbling, YG, or EBF in either main effect treatments. These results indicate that supplementation of CMC did not result in any appreciable improvements in growth, carcass or dietary net energy utilization performance, but TYL supplementation resulted in a positive effect on liver abscess prevalence. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to determine if electrolyte application (glycerol-based electrolyte solution containing potassium chloride, acetic acid, magnesium hydroxide, sodium propionate, and sodium chloride; 5.10% potassium, 1.00% sodium, and 0.87% magnesium; HydraFit--Micronutrients USA LLC, Indianapolis IN) before shipping for harvest increased cold carcass weight in beef steers. Steers (n = 40; 20 steers per treatment; BW = 659 ± 72.9 kg) were weighed 40 h before harvest, blocked by BW (n = 4 BW blocks), and assigned to one of two treatments: no HydraFit (Con) or HydraFit (HF) added to the water at 4% vol/vol (4 pens/treatment, 8 pens total). Feed and water access was not restricted nor was a shrink percentage applied to any BW measures. Thirty-six hours before harvest a 378 L water tank was filled with water from the same source the steers had been consuming since arrival. Water and feed were introduced at 36 h before harvest. Final BW was captured immediately before shipping (12 h prior to harvest). Cattle were transported 98 km to a commercial abattoir. Cattle were held in lairage with ad libitum access to water before harvest the following morning. Water intake pre-shipment was determined after the cattle were removed from the pens and transported to slaughter. Water volume was estimated by measuring water depth remaining in the tank. Depth measurements were calibrated to water volume by metering (DM-P; Assured Automation, Roselle, NJ; ± 1.0%) 0.64 cm of water into each tank and recording the liters of water metered. Hot carcass weight was determined at the time of slaughter and cold carcass data was determined after a 48-hour chill. One steer from Con was condemned at the abattoir for reasons unrelated to treatment, consequently, the contribution of this steer to the pen mean was deleted. Providing HF in the drinking water for approximately 22 hours before shipping for harvest tended to increase final body weight (P = 0.08) by 1% but had no effect (P = 0.88) on hot or cold carcass weight. In conclusion, providing a glycerol-based electrolyte solution to finished beef cattle for approximately 22 hours before shipping for harvest tended to improve final body weight. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine if additional roughage inclusion to feedlot steer finishing diets during the feeding of ractopamine hydrochloride (RH) is an effective method to improve rumen health and control liver abscess severity. Steers [n = 64; initial shrunk body weight (SBW) = 633 kg ± 35.1 kg] were sourced from an unrelated trial and remained in their previous study pens; pens (n = 8) were assigned to dietary treatment in a completely randomized design. All steers on trial were fed a common 7% [dry matter (DM) basis] roughage equivalent (RE) finishing diet composed of dry-rolled corn, dried distillers grains plus solubles, corn silage, and grass hay for the 58 d preceding study initiation. Steers were fitted with rumination tags to track daily rumination. Dietary treatments were CON: no diet change; and 12R: 5% (DM basis) RE addition to diet via grass hay during the feeding of RH. Steers were fed RH (300 mg/steer/d), finished on treatment diets for 28 d, and harvested at a commercial beef processor. Growth performance, efficiency of dietary net energy (NE) utilization, and continuous carcass data were analyzed with pen as the experimental unit (EU) and fixed effect of treatment. Minutes ruminating was analyzed as an analysis of covariance with individual animal as the EU, fixed effects of treatment, days on feed (DOF) and their interaction, and baseline minutes ruminating as a covariate in the model. Liver abscess prevalence, rumen health, and categorical carcass data were analyzed with the Fisher's exact test to determine differences between treatments. No difference (P ≥ 0.19) was observed for final SBW, average daily gain, dry matter intake, feed conversion efficiency, dressing percentage, hot carcass weight, calculated yield grade, marbling score, 12th rib fat thickness, calculated empty body fat, observed dietary NE for maintenance and gain, observed-to-expected dietary NE for maintenance and gain, or distribution of liver abscess prevalence, ruminitis score, or USDA yield grade. Ribeye area tended (P = 0.10) to differ between treatments with 12R steers exhibiting a 3.5% larger ribeye. Distribution of USDA quality grade differed (P = 0.003) between treatments with 12R steers having 25% more carcasses grading USDA average choice or better. A treatment × DOF interaction (P = 0.045) was observed for minutes ruminating per day. Daily minutes ruminating was increased (P ≤ 0.05) for 12R on d 1, 2, and 20 and tended to be increased (P ≤ 0.10) for 12R on days 10, 13, 24, and 25. Inclusion of an additional 5% RE to finishing cattle diets during a 28 d RH feeding period can be a management strategy to decrease risk of digestive upsets without sacrificing growth performance or carcass quality. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the influence that a rumen-protected B-vitamin (RPBV) blend (containing pantothenic acid, pyridoxine, folic acid, biotin, and cyanocobalamin; Vivalto, Trouw Nutrition, Isola Vicentina, Italy) had on growth performance, efficiency of dietary net energy utilization, carcass trait responses, and liver abscess severity and prevalence in beef steers fed a finishing diet. Steers (n = 246; initial shrunk body weight (BW) = 411 ± 25.8 kg) from two sources, were used in a 126-d randomized complete block design experiment. Within 48 h after arrival, steers were individually weighed and allotted to one of 24 pens (n = 10 to 12 steers; 8 pens/treatment) and randomly assigned to 1 of 3 treatments: 1) No RPBV; 2) RPBV1 at 1 g/hd/d; 3) RPBV2 at 2 g·animal-1·d-1/. During the first 14 d cattle received two transition diets. From d 15 to d 126 cattle were fed the final diet containing 53% dry-rolled corn; 23% corn silage; 20% MDGS; and 4% suspended supplement. Data were analyzed using the GLIMMIX procedure of SAS 9.4 with treatment as the fixed effect and block (Pen location) as the random effect; pen was considered the experimental unit. No differences (P ≥ 0.13) were found for dry matter intake, final live BW, average daily gain (ADG), or feed efficiency (G:F) among treatments. Carcass-adjusted final BW, ADG, and G:F were not influenced by treatment (P ≥ 0.59). Hot carcass weight, dressing percentage, marbling score, kidney-pelvicheart fat, or BW at 28% empty body fat did not differ among treatments (P ≥ 0.11). Rib eye area (REA) was altered (quadratic effect, P = 0.02) by treatment; steers from RPBV 1g had decreased REA compared with others. Additionally, calculated yield grade (YG) and calculated retail yield (RY) were altered (quadratic effect, P = 0.01) by treatment; steers from RPBV 1 g had increased YG and decreased RY compared with others. Estimated empty body fatness tended (P = 0.06) to be greater from steers fed RPBV compared with control. Overall USDA YG distribution was altered by dietary treatment (P = 0.01). The proportions of YG1 and YG5 carcasses were unaffected by treatment, but there was a shift in the proportion of carcasses that graded YG2, YG3, and YG4 among treatments. Distribution of USDA Quality Grade was not altered by treatment (P = 0.53). No differences were observed on liver abscesses among treatments. The use of RPBV altered carcass muscularity and rib fat accumulation which impacted the overall YG distribution. However, RPBV did not appreciably influence any cumulative growth performance measures liver abscess incidence or severity. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of orally administered Megasphaera elsdenii NCIMB 41125 (ME) in preconditioned calves abruptly transitioned from a receiving diet with 4% dietary starch [dry matter (DM) basis] to a growing diet with 37% dietary starch (DM basis). Preconditioned steers [n = 192; initial shrunk body weight (SBW) = 309 kg ± 20.6 kg] were assigned to microbial supplement treatment in a randomized complete block design. Treatments were CON: no ME; and LP: orally administered 20 mL of microbial supplement (2 × 1010 colony forming units ME/mL) immediately before diet change. Steers were abruptly changed from a receiving diet based upon soybean hulls and wheatlage with 4% dietary starch (DM basis) to a growing diet based upon high-moisture ear corn, dry-rolled corn, and wheatlage with 37% dietary starch (DM basis). Diets were switched on an equal DM basis to achieve abrupt change and steers were fed treatment diet for 49 d until study completion. Prior to study initiation, steers (n = 72; n = 3/pen) were fitted with wireless rumination tags to track daily activity and rumination time. Growth performance data and efficiency of dietary net energy utilization were analyzed with pen as the experimental unit, fixed effect of treatment, and random effect of block (location in the feedlot). Activity and rumination data were analyzed in a repeated measures analysis of covariance with individual animal as experimental unit, fixed effects of treatment, week, and their interaction, block (location in feedlot) as a random effect, and baseline activity and rumination as a covariate in the model. If no interaction was observed, main effect means of treatment and week were evaluated independently. For all statistical analysis, P ≤ 0.05 was declared significant and P ≤ 0.10 was declared a tendency. No difference (P ≥ 0.20) was observed between treatments for final SBW, average daily gain, dry matter intake, feed efficiency, calculated net energy (NE) for maintenance and gain or observed-to-expected ratio of NE for maintenance and gain. Additionally, no treatment × day differences (P ≥ 0.27) were observed for activity or rumination measures. Treatment effects (P < 0.01) were observed for both activity and rumination where LP steers had a 2% increase and 2% decrease in minutes per day active and ruminating respectively. Additionally, a positive linear effect (P < 0.01) of week was observed for minutes ruminating and quadratic effects (P < 0.01) of week were observed for minutes active and ruminating. Oral administration of ME had no effects on growth performance or efficiency of dietary net energy utilization in steers transitioned from a receiving diet containing 4% starch (DM basis) to a growing diet containing 37% starch (DM basis). [ABSTRACT FROM AUTHOR]

The objective was to investigate the influence of cattle origin and region of finishing on the prevalence of Salmonella, Escherichia coli O157:H7, and select antimicrobial resistance in E. coli populations. Yearling heifers (n = 190) were utilized in a 2 × 2 factorial arrangement. Heifers (n = 98) in the northern region were sourced from South Dakota (SD) while heifers (n = 92) in the southern region were sourced from Texas (TX). After feedlot arrival in each respective region, fecal Salmonella prevalence was determined, and heifers were sorted into 1 of 4 treatments: heifers sourced from SD and finished in SD (SD-SD); heifers sourced from SD and finished in TX (SD-TX); heifers sourced from TX and finished in SD (TX-SD); heifers sourced from TX and finished in TX (TX-TX). Transport for SD-TX and TX-SD heifers occurred on d 0. Fecal, pen, and water scum line (WSL) samples were collected longitudinally throughout the study; hide and subiliac lymph node (SLN) samples were collected at study end (d 78 for heifers finished in TX and d 90 for heifers finished in SD). A treatment × time interaction was observed (P = 0.01) for fecal Salmonella prevalence, with prevalence being greatest for TX-TX and TX-SD heifers before transport. From d 14 through study end, prevalence was greatest for TX-TX and SD-TX heifers compared with SD-SD and TX-SD heifers. The TX-SD heifers had a 72% decrease in Salmonella prevalence from d 1 to harvest, whereas the SD-TX heifers had a 2,200% increase in Salmonella prevalence from d 1 to harvest. Salmonella prevalence on hides were greater (P = 0.01) for heifers finished in TX compared with SD. Salmonella prevalence in SLN tended (P = 0.06) to be greater in TX-TX and SD-TX heifers compared with TX-SD and SD-SD. Fecal E. coli O157:H7 prevalence had a treatment × time interaction (P = 0.04), with SD-TX prevalence being greater than TX-SD on d 56 and SD-SD and TX-TX being intermediate. A treatment × time interaction was observed for fecal trimethoprim-sulfamethoxazole-resistant and cefotaxime-resistant E. coli O157:H7 prevalence (P ≤ 0.01). Overall, these data suggest region of finishing influences pathogenic bacterial shedding patterns, with the initial 14 d after feedlot arrival being critical for pathogen carriage. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of CaMg(CO3)2 (MIN-AD, Papillon Agricultural Company, Easton, MD; MA) and or tylosin phosphate (Tylan, Elanco, Indianapolis, IN; TY) supplementation on 24-hour behavior and rumination activity of yearling beef steers fed a finishing diet. A 2 × 2 factorial arrangement of treatments was used resulting in 4 dietary treatments: no MA and no TY (-MA/-TY), MA and no TY (MA/-TY), no MA and TY (-MA/TY), or MA and TY (MA/TY). Beef steers (n = 158; 469 ± 18.0 kg) were randomly assigned to dietary treatments with pen (n = 20 pens total, 10 pens/main effect mean, and 5 pens/simple effect mean) serving as the experimental unit. The MA was included at 1.5% of the diet (DM basis) in replacement of dryrolled corn and TY was provided at 90 mg·animal-1·d-1. Observation began at 0800 h and ended at 0750 h the following day, resulting in a 24-hour observation period. Observations were recorded on a pen basis, with number of animals/type of activity recorded every 10 minutes on d 42 on feed (22 d on finisher). Activity categories included number of animals drinking (DR), eating (EA), active (standing; AC), ruminating (RU), and resting (RE) per pen. Chewing (CHE) was determined as the sum of eating and ruminating activity. Data were analyzed as a randomized complete block design with the fixed effects of MA, TY, and their interaction; block (pen location) was considered a random effect. An interaction was noted between MA and TY for time spent drinking (P = 0.03) and ruminating (P = 0.01). Steers from -MA/TY spent more time drinking compared with the -MA/-TY and MA/TY steers; steers from MA/-TY were intermediate (P < 0.10). Steers from -MA/-TY ruminated 28% longer compared with MA/-TY steers (P = 0.05) and 20% longer than -MA/TY (P = 0.05), steers from MA/TY ruminated 16% longer than steers from MA/-TY (P = 0.05), while steers from -MA/TY were intermediate (P > 0.10). The main effect of MA tended to increase time spent eating by 19.3% (P = 0.06); however, no differences (P = 0.28) were noted for the main effects of MA or TY for minutes/day spent chewing, resting, or active. These results indicate that supplementation of MA may alter feeding behavior, resulting in increased minutes/day spent eating. In addition, supplementation of TY and MA may result in increased water intake, and alter time spent ruminating per day. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of CaMg(CO3)2 (MIN-AD, Papillon Agricultural Company, Easton, MD; MA) and/or tylosin phosphate (Tylan, Elanco, Indianapolis, IN; TY) supplementation on growth performance of yearling beef steers during transition to a finishing diet during the first 28 days on feed. Treatments were arranged in a 2 × 2 factorial arrangement including MA and TY. Beef steers (n = 156; initial BW = 469 ± 18.0 kg) were randomly assigned to dietary treatments pens (7 to 8 steers/pen) with pen (n = 20 pens total, 10 pens/main effect mean, and 5 pens/simple effect mean) serving as the experimental unit. Cattle were transitioned from a 30 % roughage receiving diet to a 7 % roughage finishing diet based on dry-rolled corn, dried distillers grains plus solubles, a liquid supplement, and oat silage over the initial 20 d period. Monensin sodium was included in the diet at 30 mg/kg (DM basis). The MA was included at 1.5 % of the diet (DM basis) in replacement of dry-rolled corn and TY was provided at 90 mg/animal·d-1. Data were analyzed according to a randomized complete block design with the fixed effects of MA, TY, or their interaction; block was considered a random effect. No interaction was noted between MA or TY (P ≥ 0.68) for any variables measured. The main effect of TY did not influence d 28 BW, ADG, DMI, or G:F (P ≥ 0.43). The main effect of MA reduced DMI by 1.9 % (P = 0.01), but did not appreciably influence d 28 BW, ADG, or G:F (P ≥ 0.42). MA may decrease DMI while maintaining similar BW gain and efficiency compared with non-supplemented calves. [ABSTRACT FROM AUTHOR]

The objective of the study was to determine the influence that initial BW has on growth performance responses, efficiency of dietary net energy (NE) utilization, and carcass traits in feedlot steers. Crossbred Charolais steers from a single source, (n = 70; initial BW = 329 ± 72.6 kg) were used in feedlot experiment at the Ruminant Nutrition Center, in Brookings, SD, during a 209-day growing-finishing period. These steers represented the lightest and heaviest proportions of steers taken from a larger group of 265 steer calves. On d 0 and d 1 BW and hip height (HH) measurements were collected for allotment proposes, and the initial experimental BW was the average between d 0 and d 1 BW. Steers were allocated to 1 of 2 treatments: 1) lighter (276 ± 16 kg; LIW) or 2) heavier (356 ± 16 kg; HIW) initial BW and allotted to 10 pens (n = 7 steers/pen; 5 pens/treatment). Steers were fed a diet containing 16% roughage once daily. Data were analyzed as a randomized complete block design with pen as the experimental unit. Treatment was included as a fixed effect and block (location) was considered a random effect in the statistical model. The LIW steers had a greater cumulative HH change compared with HIW. Final BW and carcass-adjusted (HCW/0.625) BW were greater for HIW steers by 13.1% and 13.4% respectively (P = 0.01). The HIW steers had a 14.4% greater DMI (P = 0.01) compared with LIW. Cumulative ADG was greater for HIW by 3% (P = 0.04). LIW steers had improved feed conversion (P = 0.01) by 11.3% compared with HIW. The HIW steers had greater (P < 0.05) HCW (15.5%), marbling scores (6.8%), and Yield grade (16.0%), and decreased REA/HCW (P = 0.01) by 5.9% compared with LIW. Steers from HIW tended to have greater rib fat (P = 0.09) by 15% compared with LIW. The distribution of USDA Yield grade was altered by initial BW (P = 0.04) with a shift in proportions of steers with greater numerical Yield grades for steers in HIW compared with LIW. No differences were detected (P = 0.22) for the distribution of Quality grade or liver abscess prevalence and severity. In conclusion, HIW steers had greater growth, but poorer feed efficiency compared with LIW steers. Steers with a HIW produced fatter carcasses with a greater amount of marbling. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of kernel processing of corn silage on apparent total tract digestibility (ATTD) of steers fed corn silage included at 65% of the diet (DM basis). Steers (n = 184; initial shrunk BW = 338 ± 22.3 kg) were assigned to 1 of 24 pens (8 steers/pen). Pens were randomly assigned to one of two dietary treatments (12 pens/treatment): non-kernel processed corn silage included at 65% diet DM (CON) or kernel processed corn silage included at 65% diet DM (KPCS) in a randomized complete block design with pen as experimental unit. Steers from replicates 1 to 8 spent 47-d on test and steers from replicates 9 to 12 were fed for 46-d on test. On the final day of the study, apparent total tract digestibility of diet dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), N, and starch was determined using an internal marker ratio technique using the undigested NDF residue following a 240 h in-situ incubation in ruminal fluid (uNDF240). Diet samples were collected twice daily (morning and afternoon) starting two days prior to fecal collections. Fecal collections were taken via rectal palpation on the final day of the study. Data were analyzed as a RCBD with fixed effects of KPCS diet and random effect of block (location within feedyard). Kernel processing increased DMI by 6% (P = 0.01) during the collection period and cumulative DMI throughout the study was increased by 2% for KPCS treatment (P = 0.04). Kernel processing did not enhance the ATTD of DM, OM, or starch (P = 0.71), but did decrease ATTD of NDF by approximately 6% (P = 0.04) compared with corn silage that was not kernel processed. Furthermore, kernel processing was determined to increase ATTD of N by 5% (P = 0.05). These results indicate that kernel processed corn silage may decrease apparent total tract digestibility of neutral detergent fiber due to greater intake but does not appreciably influence starch digestibility. [ABSTRACT FROM AUTHOR]

The objective of this research was to evaluate health, growth performance, and antibody titers to IBR, BVD 1 and 2, PI3, and BRSV for calves administered a respiratory and clostridia vaccine compared with no vaccination upon arrival. Single-sourced, newly weaned steers (n = 70; initial body weight (BW) = 254±5.9 kg) were allotted to 10 pens (n = 5 pens/treatment with 7 steers/pen). Steers were blocked by BW in a RCBD of VAC (vaccinated for IBR, BVD 1 and 2, PI3, and BRSV and clostridial upon arrival) or NOVAC (not vaccinated upon arrival). Steers were individually weighed on d 0 (arrival), 1, 21, and 42 for growth performance measures. Whole blood samples were collected (n = 3 steers/pen closest to the pen mean BW) on d 1, 21, and 42 via jugular venipuncture for antibody titer responses. Depression scores of 0 (normal) to 4 (moribund) were recorded for each individual steer for 21 d. Body weight gain and feed efficiency were not influenced (P = 0.10) by treatment. However, dry matter intake tended (P < 0.07) to increase as a percentage of BW by 3.5% for NOVAC compared with VAC. No treatment by day interactions (P > 0.05) were observed for depression scores or BVD 1 and 2 or PI3 titers. However, a treatment by day interaction (P < 0.03) was observed for IBR and BRSV titers. VAC steers had decreased (P < 0.05) titers for both IBR and BRSV on d 1 compared with d 21 but were similar (P > 0.05) to d 42, which were also similar (P > 0.05) to d 21 titers. Additionally, VAC steers had a 27% increase (P < 0.03) in PI3 titers compared with NOVAC steers. Collectively, growth performance was unaffected by vaccination, and vaccinated calves had increased antibody titer responses, as expected. [ABSTRACT FROM AUTHOR]

The objective was to determine if delivery method of organic trace minerals and Saccharomyces cerevisiae yeast culture product influence growth performance, feed efficiency, and hepatic trace mineral measures in newly-weaned steers. Crossbred steers (n = 192; 256 ± 14 kg) were used in a 49-d receiving experiment. Within 36h of weaning, steers were weighed, allotted to 24 pens (n = 8 steers/pen; 8 pens/treatment) and randomly assigned to treatments: traditional receiving diet (Con); traditional receiving diet plus the "stress-pack" directly in the diet (Force); traditional receiving diet plus a low-moisture, cooked molasses block fortified with the "stress-pack" (Tub). "Stress-pack" was offered the first 28 d of the 49-d. Biopsy samples were collected from a subsample of steers (n = 14 steers) on the day of weaning and subsequent samples were collected from the same steer (n = 1 steer/pen) on d 14, 28 and 49 for hepatic trace mineral concentration determination. A treatment × day interaction (P=0.01) for hepatic Cu concentration was noted. Force had greater hepatic Cu (P=0.05) compared to Tub and Con for the entire period. Tub had greater hepatic Cu compared to Con on d 14 and 28 (P < 0.05), but was similar to Con on d 49 (P>0.10). Force tended (P=0.08) to have greater DMI compared to Tub from d 1 to 14. From d 15 to 28, steers offered "stresspack" had greater DMI (P=0.01) and tended (P=0.07) to have greater ADG compared to Con by 12.5%. From d 29 to 49, "stress-pack" steers had greater DMI (P=0.01) and Force consumed 6.9% more DM compared to Tub (P=0.01). Cumulative DMI (P=0.01) and ADG (P=0.05) was greater for Force compared to Tub by 5.4% and 9.4%, respectively. Application of "stresspack" in diets offered to newly-weaned cattle enhanced production responses, but delivery method influences DMI and daily gain. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine if supplementing encapsulated butyric acid and zinc (BZ) in lambs abruptly transitioned to a finishing diet has effects on growth performance, efficiency of dietary net energy utilization, and carcass traits following a 59.5 d finishing period. Polypay wethers (n = 32; initial shrunk BW = 39 kg ± 4.8 kg) were grouped by initial shrunk BW and assigned to dietary treatment (CON: 0 g BZ/kg diet DM; BZ: 2 g BZ/kg diet DM) in a randomized complete block design (RCBD) with pen (n = 16) as experimental unit. Wethers were abruptly transitioned from growing diet (based upon grass hay, dried distillers grains plus solubles, and a soybean meal based pellet; 1.65 Mcal/kg NEm, 0.95 Mcal/kg NEg) to finishing diet (based upon whole corn, soybean hulls, and a soybean meal pellet; 2.02 Mcal/kg NEm, 1.33 Mcal/kg NEg) upon study initiation. Lambs were harvested at the South Dakota State University meat lab and empty body measures and carcass traits were recorded. Growth performance was calculated on a shrunk live basis (BW × 0.96). Data were analyzed as an RCBD with fixed effect of treatment and random effect of block. No differences (P = 0.15) were observed for final shrunk BW, ADG, DMI, feed conversion efficiency, observed-to-expected (O:E) DMI, O:E NEm, O:E NEg, EBW, dressed yield, or HCW. Percentage of boneless closely trimmed retail cuts (BCTRC) and red meat yield (RMY) were decreased (P = 0.03) for BZ vs. CON. Body wall thickness was increased (P = 0.02) for BZ vs. CON. Supplementing wethers BZ during an abrupt transition to a finishing diet had no effects on growth performance, efficiency of dietary net energy, or empty body measures and had minor effects on body wall thickness, percentage BCTRC, and RMY. [ABSTRACT FROM AUTHOR]