摘要
Monensin and virginiamycin are included in beef cattle finishing diets as prophylaxis to minimize the incidence of ruminal acidosis and liver abscesses. Due to different and probably complementary modes of action, this study aimed to determine the effects of a combination of monensin and virginiamycin, both included in the diet at recommended doses, on ruminal health, the occurrence of liver abscesses, and growth performance of feedlot-finished cattle. One hundred and forty-four steers (6 animals/pen) were fed 1 of 3 corn-based finishing diets containing 30 mg of monensin (MN), 25 mg of virginiamycin (VM), or 30 and 25 mg of monensin and virginiamycin (MN + VM), respectively, per kilogram of dry matter. Ruminal pH probes were inserted into two animals per pen and set to record pH every 10 min. On d 100, animals were slaughtered, and rumens and livers were recovered, on which occurrence and degree of ruminal damage, prevalence and number of liver abscesses, and liver scores (A−: livers with no more than two small abscesses; A+: livers with at least one large abscess or more than four medium abscesses; A: any other abscessed liver) were determined. Simultaneous inclusion of monensin and virginiamycin resulted in a 4.3% decrease (P DMI; 8.8, 9.2, and 9.2 ± 0.19 kg/d for MN + VM, MN, and VM-fed animals, respectively) and similar (P > 0.13) average daily body weight gain (ADG; 1.49 ± 0.021 kg/d) and hot carcass weight (HCW; 269 ± 1.7 kg), compared with feeding diets containing one additive or the other. Therefore, in terms of ADG, a 9.4% improvement (P P ≥ 0.74), as well as the minimum (4.98 ± 0.047), mean (6.11 ± 0.037), and maximum ruminal pH (7.23 ± 0.033) values and the time (125 ± 22.3 min/d), area (57.67 ± 12.383 pH × h), and episodes (22 ± 3.8 bouts) of pH below 5.6 (P ≥ 0.12). Overall, prevalence (24 ± 3.4%) and the number of liver abscesses (1.6 ± 0.14 abscesses/abscessed liver), liver scores (20 ± 3.1% of A− and 4 ± 1.8% of A livers), and prevalence (67 ± 3.5%) and degree of damage to the ruminal epithelium (2.5 ± 0.22% affected surface) were similar (P ≥ 0.18) across treatments; however, the occurrence of ruminal lesions tended (P ≤ 0.07) to be associated with that of liver abscesses and reduced ADG when feeding monensin alone.
摘要译文
Monensin和Virginiamycin包括在牛排饮食中，作为预防饮食，以最大程度地减少瘤胃酸中毒和肝脓肿的发生率。由于不同的和可能互补的作用方式，这项研究旨在确定Monensin和Virginiamycin的组合，均应以建议的剂量，瘤胃健康，肝脓肿的发生以及饲养场的生长性能以及饲养场的生长性能，包括在饮食中包括在饮食中。完成的牛。一百四十四个stes（6只动物/笔）在3种玉米基饮食中喂食1个含30毫克的Monensin（MN），25毫克的牙氨霉素（VM），或30和25毫克的Monensin和Viriniamycin（MN + VM），每公斤干物质。将瘤胃的pH探针插入两只动物中，并设置每10分钟记录pH。在D 100上，宰杀了动物，发现了瘤胃和肝脏，瘤胃损伤，患病率和肝脓肿数量和肝脏评分的发生和程度（A-：肝脏不超过两个小脓肿； A+：a+：肝脏：肝确定至少一个大脓肿或四个以上的介质脓肿； a：任何其他脓肿的肝脏）。同时纳入Monensin和Virginiamycin，降低了4.3％（P DMI; 8.8、9.2和9.2±0.19 kg/d，分别为MN + VM，MN和VM-FED动物），平均（P> 0.13）平均与含有一种添加剂或另一种添加剂的喂养饮食相比，每日体重增加（ADG; 1.49±0.021 kg/d）和热car体重量（HCW； 269±1.7 kg）。因此，就ADG而言，提高了9.4％（p≥0.74），以及最小值（4.98±0.047），平均值（6.11±0.037）和最大脉络脉络pH（7.23±0.033）和时间（125）±22.3分钟/d），面积（57.67±12.383 pH×H），pH值低于5.6（P≥0.12）。总体而言，患病率（24±3.4％）和肝脓肿的数量（1.6±0.14脓肿/脓肿肝），肝脏评分（20±3.1％的A-和4±1.8％的肝脏）和患病率（67±在治疗中，瘤胃上皮（2.5±0.22％的表面）的损害程度（2.5±0.22％）相似（P≥0.18）；然而，瘤胃病变的发生趋于与肝脓肿相关（p≤0.07），单独喂食monensin时的ADG降低。