回乳期奶牛血清PRL、E_2、P_4和STAT5含量的变化规律  

Change rules of PRL,E_2,P_4 and STAT5 levels in dairy cow's serum during milk withdraw period

作　　者：沈留红[1] 肖劲邦 傅宏庆[2] 巫晓峰[1] 姜思汛 钱柏霖 曹随忠[1] 余树民[1] 左之才[1] 彭广能[1] 邓俊良[1] 

机构地区：[1]四川农业大学动物医学院/动物疫病与人类健康四川省重点实验室/奶牛疾病研究中心,成都611130 [2]江苏农牧科技职业学院宠物科技学院,江苏泰州225300

出　　处：《中国农业大学学报》2018年第3期48-53,共6页Journal of China Agricultural University

基　　金：四川省教育厅重点项目(15ZA0024);四川省科技创新苗子工程项目(2017086);四川农业大学本科科研兴趣培养计划项目(KY2016062);四川肉牛创新团队项目(035Z2036)

摘　　要：为探究回乳期奶牛血清中促乳素(PRL)、雌二醇(E2)、孕酮(P4)、信号转导和转录激活因子5(STAT5)含量和产奶量变化规律及其相关性,选择规模化奶牛场产奶量为(15.43±0.60)kg,将干乳的妊娠后期奶牛20头为研究对象。干乳开始当天记为第0天,分别在第0、1、3、5、7、9和11天上午8:00采集奶牛尾静脉血,ELISA法检测血清中PRL、E2、P4和STAT5含量并对结果进行统计学处理,分析其在奶牛回乳过程中的变化规律及其相关性。结果表明:回乳期奶牛血清PRL含量和产奶量在0~1d变化不显著(P>0.05),3~11d依次降低且差异极显著(P<0.01);血清E2含量0~1d、3~5、7~9d、9~11d之间差异均不显著(P>0.05),依次呈阶梯式下降趋势;血清STAT5含量同样呈下降趋势,回乳0~5d、7~11d差异不显著(P>0.05),但0~5d与7~11d两阶段间差异极显著(P<0.01);血清P4含量从回乳0~11d变化不显著(P>0.05);回乳期奶牛产奶量与PRL、E2、STAT5含量呈极显著正相关(P<0.01),PRL、E2和STAT5含量变化两两间均呈极显著正相关(P<0.01);P4含量变化与PRL、E2、STAT5含量和产奶量变化的相关性均不显著(P>0.05)。综上所述,在奶牛回乳期间,血清中PRL、E2和STAT5含量均呈降低趋势并显著正相关,而P4含量变化不显著且与其他激素无显著相关性,为进一步研究泌乳相关激素调控奶牛回乳的作用机理提供理论依据。To explore the change rules and correlation among serum PRL,E2,P4 and STAT5 levels in dairy cows＇ serum during the period of milk withdraw,a total of 20 healthy cows in late pregnancy,which averagely produced （15.43±0.6） kg milk per day,were taken as study object.The day when cows began to dry milk was recorded as 0 d,and the venous blood from the tails was collected on 0,1,3,5,7,9 and 11 d,respectively.ELISA was used to detect the levels of PRL,E2,P4 and STAT5.The results showed that：During the period of milk withdraw,the changes of PRL level and milk yield among 0-1 d were not significantly （P〉0.05） and they were declining from 3 to 11 d with significant differences （P〈0.01）;The changes of E2 level among 0-1,3-5,7-9 and 9-11 d had no significant differences and the changes overall were on the decline.The STAT5 level also had a downward trend,and there were no significant differences between 0-5 d and from 7-11 d,while the difference between 0-5 d and 7-11 d were significant （P〈0.01）;The change of P4 level had no significant differences from 0-11 d （P〉0.05）;PRL,E2 and STAT5 had significantly positive correlation with the milk yield （P〈0.01）,the changes of PRL,E2 and STAT5 had significantly positive correlation with each other （P〈0.01）,while P4 has no significant different correlation with PRL,E2,STAT5 and milk yield （P〉0.05）.In conclusion,during the period of milk withdraw,the levels of serum PRL,E2 and STAT5 in dairy cows were declining and had significantly positive correlation with each other,while the level of P4 has no significant change and no significant correlation with others.These results provided basis for research in the influence of hormones milk withdraw.

关 键 词：奶牛 回乳期 促乳素 雌二醇 孕酮 信号转导和转录激活因子5 

分 类 号：S852.5[农业科学—基础兽医学]