作　　者： ; ; ; ; ; (王瑜）; (温万）; (邵怀峰）;

机构地区： 中国农业大学动物科技学院

出　　处： 《中国奶牛》 2009年第12期10-14,共5页

摘　　要： 本试验共收集10316条DHI记录并分析了奶牛胎次和泌乳天数对牛奶尿素氮(MUN)含量的影响以及MUN值与产奶量和乳成分的关系。结果表明,各胎次间MUN值有差异。泌乳天数在90～120d时,MUN值最高;在90～120d以前,MUN值随泌乳天数的增加而升高;在90～120d以后,MUN值大体上随泌乳天数的增加而降低。MUN值和4%标准乳产量(FCM)之间呈二次曲线相关(Y=-0.002X2+0.133X+16.88,R=0.963,P<0.001),FCM在33.3kg/d时MUN值最大;MUN值和乳蛋白含量呈二次曲线相关(Y=-0.933X2+5.862X+10.01,R=0.819,P=0.012),乳蛋白含量在3.14%时,MUN值最大;MUN值随乳脂含量的升高而降低(Y=-0.249X2+0.827X+19.59,R=0.974,P<0.001);MUN值随体细胞数的增加而增加(Y=0.001X+18.94,R=0.838,P=0.005)。 The experiment used 10316 Dairy Herd Improvemcnt（DHI）reeords to analyze the impact of parities and days in milk（DIM）on Milk Urea Nitrogen（MUN）, and the relationship between MUN and milk composition. The results showed that MUN had extremely significant difference among parities（P〈0.01）. MUN was lowest after calving, amt reached a peak at 90 to 120 DIM, and slowly declined in later lactation. There was curve correlation betwecu MUN and FCM（Y=-0.002X2＋0.133X＋16.88, R=0.963, P〈0.001）, MUN content peaked at 33.3kg/d of FCM. There was curve correlation between MUN and milk protein percentage（Y=-0.933X2＋5.862X＋10.01, R=0.819, P=0.012）, MUN concentration peaked at 3.14% of milk protein percentage. MUN concentration declined gradually with the increase of milk fat percentage（Y=-0.249X2＋ 0.827X＋19.59, R=0.974, P〈0.001）, and rose gradually with the increase of SCC（Y=0.001X＋18.94, R=0.838, P=0.005）.

关 键 词： 牛奶尿素氮 胎次 泌乳天数 产奶量 乳成分

领　　域： [农业科学] [农业科学]