Williams Melissa S, Mandell Ira Brent, Bohrer Benjamin M, Wood Katharine M
Department of Animal Biosciences, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.
Department of Food Science, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.
Transl Anim Sci. 2021 Oct 1;5(4):txab143. doi: 10.1093/tas/txab143. eCollection 2021 Oct.
Fifty-nine Angus-cross finishing steers were used to evaluate benzoic acid, active dry yeast (), or a combination of benzoic acid and active dry yeast when supplemented in a high-grain finishing diet on live animal performance, feeding behavior, and carcass characteristics. Steers were fed a high-grain diet for the final 106 d of finishing. Treatments were as follows: no additional supplementation (CON), 0.5% benzoic acid (ACD), 3 g per head per day active dry (YST), or both 0.5% benzoic acid and 3 g/head per day (AY). Steers were weighed every 14 d, and ultrasound was performed for rib and rump fat thickness at the beginning (day 1), middle (day 57), and end (day 99) of the experiment. Insert feeding stations were used to collect individual feeding behavior data and DMI daily throughout. Blood samples were collected on days 21 and 22 and days 99-101 to assess plane of nutrition and metabolism. Ruminal fluid samples were collected by oral gavage 4 wk prior to slaughter. Carcass characteristics were examined at a federally inspected slaughter facility. Data were analyzed using PROC GLIMMIX of SAS with initial body weight (BW) as a covariate. Benzoic acid supplementation increased ( = 0.002) overall dry matter intake (DMI) compared to YST and CON steers, which may be due to a faster eating rate ( ≤ 0.008). Animal performance parameters (BW, average daily gain, feed conversion, and ultrasound fat depth) were not different ( ≥ 0.11) among treatment groups. Aspartate aminotransferase concentration was greatest ( ≤ 0.01) for YST steers, which may have been reflected in numerically greater liver abscesses. Carcass traits did not differ ( ≥ 0.33) among treatment groups. Ruminal pH was greater ( = 0.006) for ACD steers than AY steers (pH of 6.16 vs. 5.66, respectively), which indicated that there may be an interactive effect between benzoic acid and active dry yeast. To summarize, steers fed a high-grain finishing diet supplemented with benzoic acid, active dry yeast, or both benzoic acid and active dry yeast had similar growth performance and carcass characteristics compared to those without supplementation. However, the addition of benzoic acid alone increased DMI, variation in DMI, eating rate, and ruminal pH. Future studies are warranted to further investigate the impacts of benzoic acid on the ruminal environment of feedlot cattle.
选用59头安格斯杂交育肥牛来评估苯甲酸、活性干酵母或苯甲酸与活性干酵母组合添加到高谷物育肥日粮中对活体动物性能、采食行为和胴体特性的影响。在育肥的最后106天，给牛饲喂高谷物日粮。处理方式如下：不额外添加（CON）、0.5%苯甲酸（ACD）、每头每天3克活性干酵母（YST）或0.5%苯甲酸与每头每天3克活性干酵母同时添加（AY）。每14天称一次牛的体重，并在实验开始（第1天）、中期（第57天）和末期（第99天）对肋骨和臀部脂肪厚度进行超声检测。使用插入式饲喂站在整个实验期间每天收集个体采食行为数据和干物质采食量（DMI）。在第21天和第22天以及第99 - 101天采集血样，以评估营养水平和代谢情况。在屠宰前4周通过口腔灌服采集瘤胃液样本。在联邦检查的屠宰场检查胴体特性。数据使用SAS的PROC GLIMMIX进行分析，初始体重（BW）作为协变量。与YST组和CON组的牛相比，补充苯甲酸使总体干物质采食量（DMI）增加（P = 0.002），这可能是由于采食速度更快（P≤0.008）。各处理组之间的动物性能参数（BW、平均日增重、饲料转化率和超声脂肪深度）没有差异（P≥0.11）。YST组的牛天冬氨酸转氨酶浓度最高（P≤0.01），这可能在肝脏脓肿数量较多上有所体现。各处理组之间的胴体性状没有差异（P≥0.33）。ACD组牛的瘤胃pH值高于AY组（分别为6.16和5.66，P = 0.006），这表明苯甲酸和活性干酵母之间可能存在交互作用。总之，与未添加的牛相比，饲喂添加苯甲酸、活性干酵母或同时添加苯甲酸和活性干酵母的高谷物育肥日粮的牛具有相似的生长性能和胴体特性。然而，单独添加苯甲酸会增加DMI、DMI的变异性、采食速度和瘤胃pH值。未来有必要进一步研究苯甲酸对育肥牛瘤胃环境的影响。
