【摘要】 试验旨在研究日粮添加异位酸(branched-chain volatile fatty acids, BCVFA)与叶酸(folic acid, FA)对犊牛生长性能、氮平衡与血液代谢产物的影响。试验选用16头60日龄、体重(BW)(91±5.3) kg的中国荷斯坦奶公牛,进行为期80 d的2×2因子饲养试验。结果表明:BCVFA与FA对犊牛消化氮、沉积氮、沉积氮/采食氮和沉积氮/消化氮存在交互作用(P<0.05)。BCVFA与FA显著提高了犊牛干物质采食量、日增重和饲料效率(P<0.05)。采食氮、消化氮、沉积氮、沉积氮/采食氮和沉积氮/消化氮显著增加(P<0.05);总氮排泄量显著降低(P<0.05)。血液葡萄糖、总蛋白和白蛋白显著增加(P<0.05);尿素氮浓度显著降低(P<0.05)。综上可知,20 g/d BCVFA和0.1 mg/kg BW FA均能促进犊牛生长,提高日粮氮利用率。更多还原

【Abstract】 The objective of the study was to evaluate the effects of branched-chain volatile fatty acids(BCVFA) and folic acid(FA) supplementation on growth performance, nitrogen balance and blood metabolites in dairy calves. Sixteen Chinese Holstein male calves [60 days of age;(91±5.3) kg of body weight] were used in a 2×2 factorial feeding experiment of 80 days. The results showed that there was an interaction for digestible nitrogen, nitrogen retention, nitrogen retention/nitrogen intake and nitrogen retention/digestible nitrogen(P<0.05). Supplementation with BCVFA or FA increased dry matter intake, average daily gain and feed efficiency(P<0.05). Nitrogen intake, digestible nitrogen, nitrogen retention, nitrogen retention/nitrogen intake and nitrogen retention/digestible nitrogen increased(P<0.05), but total nitrogen excretion decreased(P<0.05) with BCVFA or FA supplementation. Blood glucose, total protein and albumin increased(P<0.05), but urea nitrogen decreased(P<0.05) with BCVFA or FA supplementation. The data indicated that supplementation with BCVFA(20 g/d) or FA(0.1 mg/kg BW) improved growth performance and nitrogen utilization in dairy calves.更多还原