非蛋白氮对高产荷斯坦奶牛生产性能的影响

Effect of Non-protein Nitrogen on Dairy Production of High Yield Holstein Cows

本文通过配对试验研究了非蛋白氮对高产荷斯坦奶牛生产性能、乳成分和体细胞数的影响。以泌乳天数、产奶量相近和胎次相同为原则在高产牛中对牛只进行配对,83对符合配对要求的牛只被随机分为试验组和对照组。对照组TMR日粮不变;在试验组TMR日粮中添加非蛋白氮(50 g/头·天),减少豆粕用量(350 g/头·天),基础日粮的其它组分与对照组一致。本试验预试期7天,正式试验期60天。61对奶牛符合整个试验的要求。试验组产奶量平均值比对照组高0.47 kg/头,试验期间两组乳成分和体细胞数均无明显变化。非蛋白氮对荷斯坦奶牛的产奶量有一定程度的提高,对乳成分和体细胞数没有明显的影响。

This study was designed to determine the influence of non-protein nitrogen on milk production,milk composition and somatic cellcount of high yield Holstein cows. Eighty-three groups of cows with similar lactation days,similar milk production and same parity were divided into experimental and control groups randomly. TMR diets of control group unchanged and the test group’s were supplemented with non-protein nitrogen(50 g/head?d),at the mean time,reduced the dosage of soybean hul s (350 g/head?d ),other components of the basal diet compared with the control group were unchanged. The test was divided into pre-test(7 days) and main test(60 days). Sixty-one pairs of cows met the requirements throughout the test. The average of daily milk production of experimental group was higher than control group(0.47 kg/head).Milk composition and somatic cellcount of experimental and control group did not change significantly during the test. Non-protein nitrogen has some improvement on milk production performance of Holstein cows,but no signiifcant effect on milk composition and somatic cellcount.