摘要
Essential oils (EO) are secondary metabolites derived from plants that have antimicrobial properties which may prevent liver abscesses in feedlot cattle. Seventy-two Angus × Simmental crossbred steers (358 ± 7.6 kg initial BW) were blocked by weight and breed composition and randomly allocated to 3 treatments (4 pens/treatment, 6 steers/pen) to determine the effects of an EO blend or tylosin on performance, liver abscesses, carcass characteristics and meat quality. Treatments were delivered in a premix with dried distillers grains with solubles (DDGS) that were top-dressed daily at a rate of 454 g/steer daily (CON: no additives, TYL: 90 mg/steer daily tylosin, and EO: 1 g/steer daily essential oil blend). The basal diet contained (DM basis) 54% cracked corn, 26% DDGS, 14% corn silage and 6% supplement. Steers were slaughtered at two different time points when a target weight of 624 kg was achieved. Longissimus lumborum muscle samples were taken caudal from the last rib on the right side of each carcass for pH, tenderness, purge and cook loss, and lipid oxidation analyses. Statistical analyses were conducted using the MIXED procedure of SAS. Performance characteristics, including weight, ADG, DMI and gain:feed, did not differ among treatments (P ≥ 0.54). Similarly, no differences were observed in carcass characteristics (P ≥ 0.19). Steers fed EO tended to have an increased prevalence of liver abscesses in the A category (P = 0.10) as compared to CON and TYL. Purge loss was decreased (P = 0.02) for EO steaks compared to CON and TYL, but there were no differences in cook loss, Warner-Bratzler shear force, pH or lipid oxidation among treatments (P ≥ 0.32). In conclusion, an EO blend or tylosin in the diet of finishing steers did not affect growth performance or carcass characteristics, and little difference was observed in liver abscess incidence or meat quality attributes.
摘要译文
精油（EO）是来源于植物的次生代谢产物，具有抗微生物特性，可防止饲养场牛肝脓肿。七十二只安格斯×西门塔尔杂交种ers牛（358±7.6 kg初始体重）受体重和品种组成的限制，随机分配到3种处理方式（4笔/处理，6 ers /笔）以确定EO混合物或泰乐菌素的作用在性能，肝脓肿，car体特征和肉质上。用预混合的干酒糟和预溶物（DDGS）进行处理，每天以454克/转向的速度（CON：无添加剂，TYL：90毫克/转向的泰乐菌素和EO：1克）进行追肥。 /每天搅拌精油）。基础日粮含（干物质）54％的玉米脆皮，26％的DDGS，14％的玉米青贮饲料和6％的补品。当达到624公斤的目标重量时，在两个不同的时间点宰杀了ers牛皮。从每个car体右侧的最后一个肋骨尾部提取腰最长肌肌肉样品，以进行pH，压痛，吹扫和蒸煮损失以及脂质氧化分析。使用SAS的MIXED程序进行统计分析。各处理之间的体重，ADG，DMI和增重：饲料等性能特征无差异（P≥0.54）。同样，car体特性无差异（P≥0.19）。与CON和TYL相比，饲喂EO的ers牛A类肝脓肿的患病率升高（P = 0.10）。与CON和TYL相比，EO牛排的吹扫损失降低了（P = 0.02），但处理之间的蒸煮损失，Warner-Bratzler剪切力，pH或脂质氧化没有差异（P≥0.32）。总之，育肥公牛日粮中的EO共混物或泰乐菌素不会影响生长性能或car体特性，在肝脓肿发生率或肉质属性方面几乎没有观察到差异。
J.R.Pukrop[a];B.T.Campbell[b];J.P.Schoonmaker[a]. Effect of essential oils on performance, liver abscesses, carcass characteristics and meat quality in feedlot steers[J]. Animal Feed Science and Technology, 2019,257