摘要
Scientific literature on the use of antibiotic growth promoters (AGP) in beef cattle consuming forage-diets was reviewed. Database summarizes 136 comparisons between untreated and AGP-treated cattle from 48 bibliographic references. Performance data of cattle receiving AGP either alone or in combination with 17 β-estradiol implants was statistically analyzed. Forage quality, in terms of average daily gain (ADG), differentially influenced (P = 0.1) the effect of AGP on beef cattle performance. As the quality of forage increased, the estimated net ADG response to monensin decreased and that to lasalocid increased. ADG increased quadratically (P 0.01) with increasing doses of monensin (R2 = 0.71) or lasalocid (R2 = 0.63). Ionophore-dosage level quadratically improved (P = 0.01; R2 = 0.52) feed conversion (FCONV) of cattle without affecting their dry matter intake (DMI; P > 0.1). A linear relationship (P 0.01) between ADG and dose of tetronasin (R2 = 0.64) or lysocellin (R2 = 0.52) was also observed. The combination of monensin and 17β-estradiol implants resulted in an additive effect on ADG of grazing cattle. The experimental results reviewed show that, in beef cattle consuming forage-based diets, ionophores improve ADG and FCONV in a dose-dependent manner, with little or no effect on DMI. In addition, results suggest that forage quality influences the direction of the ADG response to AGP supplementation in cattle. Summarized data from beef cattle implanted with 17β-estradiol and/or supplemented with monensin indicate that the combined response of these two compounds on cattle grazing high-quality pastures has no effect on ADG over that obtained by 17β-estradiol alone.
摘要译文
综述了关于抗生素生长促进剂（AGP）在肉牛食用饲料中的应用的科学文献。数据库总结了来自48个参考文献的未处理牛和AGP处理牛之间的136个比较。统计分析了单独或与17β-雌二醇植入物组合接受AGP的牛的性能数据。根据平均日增重（ADG），饲料质量差异地影响（P = 0.1）AGP对肉牛性能的影响。随着牧草质量的增加，对莫能菌素的净ADG反应减少，对拉沙里菌素的反应增加。随着莫能菌素（R 2 = 0.71）或拉沙里菌素（R 2 = 0.63）的剂量增加，ADG呈二次方增加（P <0.01）。离子载体剂量水平二次改善（P = 0.01; R 2 = 0.52）牛的饲料转化率（FCONV），不影响其干物质摄入量（DMI; P> 0.1）。还观察到ADG与tetronasin剂量（R 2 = 0.64）或lysocellin（R 2 = 0.52）之间的线性关系（P <0.01）。莫能菌素和17β-雌二醇植入物的组合导致对放牧牛的ADG的累加效应。回顾的实验结果表明，在以饲料为基础的日粮中，离子载体以剂量依赖的方式改善ADG和FCONV，对DMI的影响很小或没有影响。此外，结果表明饲料质量影响ADG对牛AGP补充反应的方向。植入17β-雌二醇和/或补充莫能菌素的肉牛的汇总数据表明，这两种化合物对放牧高质量牧场的牛的综合反应对ADG没有影响，而不是单独使用17β-雌二醇。
G.Bretschneider[a][b];J.C.Elizalde[c];F.A.Pérez[d];. The effect of feeding antibiotic growth promoters on the performance of beef cattle consuming forage-based diets: A review[J]. Livestock Science, 2008,114(2-3): 135-149