日粮蛋白质水平对生长期闽南黄牛氮代谢的影响

Effects of Dietary Protein Levels on Nitrogen Digestibility in Growing Minnan Yellow Cattle

选用9头14月龄闽南黄牛公牛,按重复3×3拉丁方设计,进行了氮平衡试验。研究了日粮蛋白质水平对氮消化与沉积规律及血液某些相关指标的影响。结果表明:随着蛋白质水平的提高,氮的进食量显著增加;氮的表观消化率、氮沉积量也显著增加(P<0.01)。氮的表观消化率(％)=43.26+0.58X,(r=0.9412,n=9);沉积氮(g/d)=1.86+0.37X,(r=0.9216,n=9)。

In a repeat 3×3 Latin square experiment design,nitrogen balance trials were conducted with nine 14-month-old Minnan yellow cattle bulls to study effects of dietary protein levels on nitrogen digestion and deposition regulation. The results showed that Increasing dietary protein level (9% ,12% ,15%)resulted in significantly increased N intake and apparent N digestibility. The relationship between N intake and apparent N digestibility was:N digestibility (%)= 43. 26+0. 58[N intake (g/d)], (r = 0. 9412,n = 9); As dietary protein level increased,the urinary N excretion increased significantly(P<0. 01) ,and the N deposition also in creased. The linear relationship between N intake and N deposition was significant: N deposition (g/d) =1. 86+0. 37[N intake (g/d)], (r= 0. 9216,n=9).