过瘤胃甜菜碱对哈萨克羊羔羊生产性能、消化代谢和屠宰性能的影响OA

In order to evaluate the effects of dietary rumen-protected betaine(RPB)supplementation on growth performance,nutrient digestibility,and slaughter characteristics of growing Kazakh fat-tailed lambs,twenty 3-month-old male lambs with initial body weight(30.02±1.55)kg were randomly assigned to four dietary treatments(5 lambs per group):control group(CON)fed a basal diet,and three treatment groups supplemented with 2(L-RPB),4(M-RPB),8(H-RPB)g/d of RPB.The experiment included a 10-day adaptation period followed by a 90-day feeding trial.Results showed that no significant differences among groups in growth performance or apparent nutrient digestibility(P＞0.05).However,RPB supplementation significantly reduced abdominal fat weight and abdominal fat percentage compared with the CON group(P＜0.05).No significant differences were observed in slaughter traits such as live weight before slaughter,carcass weight,dressing percentage,carcass length,net meat weight,lean meat weight,fat meat weight,skin and fat weight,tail fat weight,eye muscle area,and GR value(P＞0.05).Similarly,the proportions of net meat,lean meat,fat meat,skin fat,and tail fat did not differ among groups(P＞0.05).In conclusion,dietary supplementation with rumen-protected betaine reduced fat deposition and modestly increased lean tissue proportion in growing Kazakh fat-tailed lambs,without affecting growth performance and nutrient digestibility.