中国荷斯坦奶牛乳尿素氮非营养影响因素及其与泌乳性能的相关性分析  

Non⁃Nutritional Influence Factors on Milk Urea Nitrogen and Its Correlation with Lactation Performance of Chinese Holstein Dairy Cows

作　　者：赵小博 余诗强 蒋林树[1] 赵玉超 杨蕾[2] ZHAO Xiaobo;YU Shiqiang;JIANG Linshu;ZHAO Yuchao;YANG Lei(Beijing Key Laboratory of Dairy Cow Nutrition,Beijing University of Agriculture,Beijing 102206,China;Institute of Data Science and Agricultural Economics,Beijing Academy of Agriculture and Forestry,Beijing 100097,China)

机构地区：[1]北京农学院,奶牛营养学北京重点实验室,北京102206 [2]北京市农林科学院数据科学与农业经济研究所,北京100097

出　　处：《动物营养学报》2023年第8期5209-5225,共17页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：北京市教育委员会重点项目(KZ202010020029);北京农学院科技创新“火花行动”支持计划(BUA-HHXD2022011);现代农业产业技术体系北京市家畜创新团队。

摘　　要：本试验旨在揭示中国荷斯坦奶牛乳尿素氮(MUN)浓度非营养影响因素的变化规律及其与泌乳性能的关系,探究非营养因素影响MUN浓度的内在机制。以北京、河北等地的17家奶牛场共24 508头泌乳奶牛的生产性能测定(DHI)报告为研究材料,利用固定模型分析牛场效应、胎次效应、产犊季节、泌乳天数、泌乳季节、产奶量、乳脂率、乳蛋白率、乳糖率和体细胞评分对MUN浓度的影响,并按高(16~27 mg/dL)、正常(10~16 mg/dL)和低(0~16 mg/dL)对MUN浓度进行分组,通过显著性和相关性等多种方法分析非营养影响因素的规律及MUN对泌乳性能的影响。结果表明:1)牛场效应、泌乳季节和泌乳天数是影响MUN浓度的重要非营养影响因素;2)MUN浓度在群体水平上与乳脂率呈极显著正相关(r=0.813,P<0.01),与体细胞评分呈极显著负相关(r=-0.441,P<0.01),且MUN浓度在夏季最低、冬季最高;3)相同乳脂率数据集分析表明,泌乳季节、体细胞评分与MUN浓度并无相关性(r<0.100);4) MUN浓度的变化极显著影响乳蛋白率、乳脂率、校正乳含量及脂蛋比(P<0.01)。综上所述,非营养因素的波动导致了MUN浓度的规律性变化,且泌乳季节、体细胞评分非营养因素通过影响乳脂率进而导致MUN浓度变化,关于乳脂率与MUN浓度的变化机理有待进一步研究。The purpose of this experiment was to reveal the variation regularity of non⁃nutritional factors affect⁃ing milk urea nitrogen(MUN)concentration and its relationship with lactation performance of Chinese Hol⁃stein dairy cows,and to explore the internal mechanism of non⁃nutritional factors affecting MUN concentration.Using dairy herd improvement(DHI)reports of 24508 lactating dairy cows from 17 dairy farms in Beijing and Hebei as research materials,the fixed model was used to analyze the effects of dairy farm effect,parity effect,calving season,lactation days,lactation season,milk yield,milk fat percentage,milk protein percent⁃age,milk lactose percentage and somatic cell score on MUN concentration,and with MUN concentration was divided into high(16 to 27 mg/dL),normal(10 to 16 mg/dL)and low(0 to 16 mg/dL)groups,the rules of non⁃nutritional factors and the effect of MUN on lactation performance were analyzed by significance and correlation methods.The results showed as follows:1)the dairy farm effect,lactation season and lactation days were important non⁃nutritional factors affecting MUN concentration;2)at the population level,MUN concentration was extremely significantly positively correlated with milk fat percentage(r=0.813,P<0.01),and extremely significantly negatively correlated with somatic cell score(r=-0.441,P<0.01),and MUN concentration was the lowest in summer and the highest in winter;3)the analysis of the same milk fat percent⁃age data set showed that lactation season and somatic cell score had no correlation with MUN concentration(r<0.100);4)MUN concentration extremely significantly affected the milk protein percentage,milk fat percent⁃age,corrected milk content and fat to protein ratio(P<0.01).In conclusion,the fluctuation of non⁃nutritional factors leads to the regular change of MUN concentration,and the non⁃nutritional factors such as lactation sea⁃son and somatic cell score affect the milk fat percentage and thus lead to the change of MUN concentration.The change mechanism be

关 键 词：荷斯坦奶牛 乳尿素氮 固定模型 非营养影响因素 泌乳性能 

分 类 号：S823[农业科学—畜牧学]