PERFORMANCE, BODY TEMPERATURE AND BLOOD METABOLITES OF FEEDLOT STEERS AS INFLUENCED BY ENVIRONMENTAL CONDITIONS AND SUPPLEMENTATION OF ZILPATEROL HYDROCHLORIDE

Trial one was conducted at the United States Meat Animal Research Center (MARC) near clay center, NE during the summer of 2014. The objective of this trial was to measure the effects of supplementing zilpaterol hydrochloride (ZH) for the final 21 days of the finishing period, and shade, on performance, body temperature, respiration rate, and mobility of finishing beef steers. Feeding ZH increased hot carcass weight, dressing percent, longissimus muscle area, and reduce USDA yield grade. Shade did not affect steer performance and did not reduce body temperature. Zilpaterol hydrochloride increased respiration rate when compared to control cattle and had minimal effect on animal mobility. Zilpaterol hydrochloride and shade had little effect on steer body temperature. Trial 2 and 3 were conducted during the summer and fall/winter of 2014 at the University of Nebraska-Lincoln (UNL) Agricultural Research and Development Center (ARDC) near mead, NE. The objective of these trials was to assess the effects of environmental conditions on body temperature and blood metabolites across season on finishing steers. Body temperature was correlated to environmental temperature during both trials however the correlations weren’t as strong for the winter trial. Many blood metabolites were correlated to environmental and rumen temperatures suggesting that blood metabolites are affected by environmental conditions. Trial 4 was conducted at UNL ARDC with the objective to determine the effect of feeding Agrimos (Lallemand Animal Nutrition; Montreal, Canada) and 2.5-cm ground wheat straw to finishing steers, during the summer, on body temperature and panting score in addition to performance, and blood metabolites. Hot carcass weight, dressing percent, LM area, and marbling score were not different between treatments. The addition of Agrimos (Lallemand Animal Nutrition; Montreal, Canada) increased steer body temperature with no impact on steer performance. The addition of finely ground wheat straw decreased steer panting score and reduced feed efficiency over both the control and Agrimos fed cattle. Control cattle had greater 12th rib fat depth and as a result USDA yield grade. Advisor: Galen E. Erickso

Effect of Urea and Distillers Inclusion in Dry- Rolled Corn Based Diets on Heifer Performance and Carcass Characteristics

Crossbred heifers (n=96, BW = 810 ± 20) were utilized to evaluate the effects of increasing wet distillers grains plus solubles and urea inclusion in a dry rolled corn based finishing diet on performance and carcass characteristics. Heifers were individually fed using a calan gate system with a 2 × 2 factorial arrangement of treatments. Factors included distillers inclusion at either 10 or 20% of diet DM and urea inclusion at either 0.2 or 1.4% of diet DM. Th ere was no difference for final body weight, average daily gain, and feed conversion on a live or carcass adjusted basis for either urea or distillers inclusion in the diet. Dry matter intake was reduced with increased urea inclusion; however, distillers inclusion did not influence intake. Added distillers and urea in the diet had minimal impact on performance suggesting supplemental urea in a dry rolled corn based finishing diets is of minimal benefit when feeding at least 10% distillers grains

Evaluation of Masters Choice Corn Silage on Growing Steer Performance

A growing study evaluated three corn silage hybrids on growing steer performance. Th e three hybrids were: a conventional hybrid- Farm Choice (CON) commonly grown in Eastern Nebraska which served as the control, Masters Choice hybrids MCT6365 RIB (MC1) selected to improve fi ber and starch digestion and MCT6733 GT3000 (MC2) that has been selected to improve fi ber digestion in cattle. Relative to CON, feeding hybrid MC1 resulted in similar DMI, but numerically increased ADG which significantly improved F:G compared to CON. Feeding MC2 led to greater DMI, similar ADG, and poorer (greater) F:G compared to CON. Feeding Masters Choice hybrid MCT6365 RIB (MC1) corn silage at 80% of the diet DM likely improved digestion and energy availability to the steers, which allowed greater ADG and improved F:G, while the opposite was true for MC2. Differences in hybrids exist when fed to growing cattle at 80% of the diet

Impact of Ramaekers Immune Primer on Finishing Beef Cattle Performance and Liver Abscess Rate

A feedlot study was conducted comparing a natural feed additive (Ramaekers Immune Primer) to Tylan or nothing on receiving and finishing performance. There were no differences for final BW, ADG, F:G, HCW, marbling, LM area, or fat thickness due to treatment. Liver abscess incidence and severity were reduced in steers fed Tylan, no differences were noted between Ramaekers Immune Primer and no additive. There was no difference in number of cattle treated for respiratory illness. Steers on the Ramaekers Immune Primer treatment had lower feed intake during the receiving period but had similar ADG and numerically better F:G at day 19 compared the control. These results suggest Ramaekers Immune Primer may be more beneficial, leading to increased performance, for younger, naive calves during the receiving phase

Effects of Urea and Distillers Inclusion in Finishing Diets on Steer Performance and Carcass Characteristics

An experiment was conducted to evaluate the effect of supplemental urea in dry rolled corn based finishing diets containing low inclusions of distillers grains. Treatments were set up in a 3 × 3 factorial arrangement. The first factor was wet distillers inclusion at either 10, 15, or 20% of diet DM. The second factor was urea inclusion at either 0, 0.5, or 1.0% of diet dry matter. Increasing inclusion of distillers linearly improved feed conversion and linearly reduced dry matter intake. An interaction for feed efficiency was observed where there was no effect of added urea when 10% or 20% distillers was fed and a quadratic effect was observed when 15% distillers grains was fed where 0.5% urea appeared to be optimum. Added urea in a finishing diet with 20 or 10% distillers has minimal impact on finishing performance; however, feeding 0.5% urea in a 15% distillers diet may be beneficial

Effect of Urea and Distillers Inclusion in Dry- Rolled Corn Based Diets on Heifer Performance and Carcass Characteristics

Crossbred heifers (n=96, BW = 810 ± 20) were utilized to evaluate the effects of increasing wet distillers grains plus solubles and urea inclusion in a dry rolled corn based finishing diet on performance and carcass characteristics. Heifers were individually fed using a calan gate system with a 2 × 2 factorial arrangement of treatments. Factors included distillers inclusion at either 10 or 20% of diet DM and urea inclusion at either 0.2 or 1.4% of diet DM. Th ere was no difference for final body weight, average daily gain, and feed conversion on a live or carcass adjusted basis for either urea or distillers inclusion in the diet. Dry matter intake was reduced with increased urea inclusion; however, distillers inclusion did not influence intake. Added distillers and urea in the diet had minimal impact on performance suggesting supplemental urea in a dry rolled corn based finishing diets is of minimal benefit when feeding at least 10% distillers grains

Evaluation of Masters Choice Corn Silage on Growing Steer Performance

A growing study evaluated three corn silage hybrids on growing steer performance. Th e three hybrids were: a conventional hybrid- Farm Choice (CON) commonly grown in Eastern Nebraska which served as the control, Masters Choice hybrids MCT6365 RIB (MC1) selected to improve fi ber and starch digestion and MCT6733 GT3000 (MC2) that has been selected to improve fi ber digestion in cattle. Relative to CON, feeding hybrid MC1 resulted in similar DMI, but numerically increased ADG which significantly improved F:G compared to CON. Feeding MC2 led to greater DMI, similar ADG, and poorer (greater) F:G compared to CON. Feeding Masters Choice hybrid MCT6365 RIB (MC1) corn silage at 80% of the diet DM likely improved digestion and energy availability to the steers, which allowed greater ADG and improved F:G, while the opposite was true for MC2. Differences in hybrids exist when fed to growing cattle at 80% of the diet

Effect of Adding Urea to Finishing Diets Containing Two Different Inclusions of Distillers Grains on Steer Performance and Carcass Characteristics

The effects of adding urea to a dry rolled corn based finishing diet containing low inclusions of distillers grains was evaluated. Treatments were designed as a 2 × 4 factorial arrangement with factors consisting of wet distillers inclusion (either 12 or 20% of diet DM) and urea inclusion (0, 0.4, 0.8, 1.2% of diet DM). There were no significant interactions observed between distillers inclusion and urea inclusion in the diet. Increasing inclusion of distillers grains improved carcass adjusted average daily gain and feed conversion and reduced dry matter intake. Increasing distillers inclusion also increased 12th rib fat and had a tendency to increase hot carcass weight. There were no significant linear or quadratic responses for increasing urea inclusion in the diet. These data suggest that when feeding at least 12% distillers in the diet, supplemental urea has minimal impact on animal performance

Impact of Feeding Aspergillus Subspecies Blend and Di! erent Corn Processing Methods on Finishing Beef Cattle Performance and Carcass Characteristics

A feedlot study utilizing 320 crossbred calf- fed steers (initial body weight 588 lb) compared the effect of feeding an Aspergillus additive in either dry- rolled corn or high- moisture corn finishing diets on cattle performance and carcass characteristics. Steers were fed 0 g/steer daily or 10 g/steer daily Aspergillus for both corn processing methods. # ere were no significant interactions between corn processing method and Aspergillus. Feeding finishing cattle Aspergillus did not impact performance compared to feeding none. Cattle fed dry- rolled corn had greater final body weight, dry matter intake, and gain compared to high- moisture corn diets. But cattle fed high- moisture corn had a 6.25% decrease in feed- to- gain compared to dry- rolled corn. These data suggest that feeding Aspergillus does not affect performance. The lower dry matter intake and average daily gain observed would suggest a potential acidosis problem for high- moisture corn compared to dry- rolled corn- based finishing diets

Evaluation of Corn Distillers Solubles on Finishing Steer Performance

A finishing study was conducted to evaluate the effects of feeding 0, 8, 16, or 20% corn distillers solubles (CDS), as well as the effects of feeding a combination of 16% CDS and 20% wet distillers grains plus solubles (WDGS) to replace a blend of dry-rolled and high-moisture corn on finishing steer performance. As inclusions of CDS increased, ADG linearly increased and F:G linearly decreased. Feeding value of CDS at 20% inclusion was determined to be 147% compared to the corn blend. The addition of WDGS resulted in a decrease in DMI with similar ADG, resulting in a decrease in F:G. Feeding a combination of CDS and WDGS resulted in a feeding value of 161% compared to corn. Feeding CDS up to 20% or in combination with WDGS displaces corn in finishing diets and improves ADG and F:G