荷斯坦牛泌乳早期体细胞数的群体特征及影响因素分析

Population Characteristics and Factors Influencing Somatic Cell Count in Early Lactation Stage in Holstein

为探究北京地区荷斯坦牛泌乳早期牛奶体细胞数(SCC)的群体规律及其影响因素,本研究测定了北京某牧场2018年6~7月份产犊的124头母牛产后0~7天内每天的SCC,利用SAS软件GLM过程分析泌乳早期SCC的影响因素,并用REG过程分析泌乳早期体细胞评分(SCS)与后期测定日SCS之间的关系。结果表明,泌乳早期SCC(均值为(860±1 287)千个·mL^-1)高于产后8~133天的测定日SCC。胎次、泌乳天数、环境温湿度均对泌乳早期SCS有显著的影响(P<0.05)。泌乳早期SCS与产后39~68天的测定日SCS之间存在极显著的回归关系(P<0.01),回归系数为0.40。荷斯坦牛泌乳早期(产后0~7 d)SCC均值高于泌乳期内其他阶段的SCC均值,且荷斯坦牛泌乳早期SCC对母牛的不同生理状态及所处环境因素的变化敏感。本研究为泌乳早期SCC的遗传分析奠定了基础,为牧场在母牛产后根据泌乳早期SCC对乳房炎进行管理提供了参考。

The objective of this study was to explore the general characteristics of somatic cell count(SCC) and analyze the factors affecting SCC of Holstein in early lactation stage in Beijing area. From June to July 2018, daily SCC of 124 cows in a dairy farm was measured in first 7 days after calving. The factors influencing SCC in early lactation stage were analyzed by GLM procedure of SAS software, and the relationship between somatic cell score(SCS) during first 7 days after calving and test-day SCS in following months was analyzed by REG procedure. The results showed that the SCC in early lactation stage was higher than test day SCC(8-133 days after calving), and the average SCC from 0 to 7 days after calving was(860±1 287) 103·mL^-1. Parity, days in milk, environmental temperature and humidity had significant impacts on SCS in early lactation stage(P<0.05). There was a significant regression relationship between SCS in early lactation stage and test day SCS in 39-68 days after calving(P<0.01), and the regression coefficient was 0.40. The average SCC of Holstein in early lactation stage(0-7 d) was higher than the average SCC in other stages. And the SCC of Holstein in the early lactation stage was sensitive to changes of different physiological states and environmental factors of cattle. This study laid the foundation for the genetic analysis of SCC in early lactation stage, and provided a reference for the management of mastitis in dairy farm according to SCC in the early lactation stage.