摘要
为了探究不同胎次和热应激程度对奶牛产奶量、乳脂率、乳蛋白率、脂蛋比、体细胞数和高峰奶量的影响,收集了广州某奶牛场360头荷斯坦泌乳母牛近5年的奶牛生产性能测定体系(DHI)数据,用R (Version 3. 3. 2)和SPSS 20. 0软件分析了不同胎次和热应激程度对产奶量及乳成分的影响。结果:相比于其他胎次的奶牛,头胎母牛产奶量、高峰奶量较低(P<0. 05);头胎牛的脂蛋比显著高于其他胎次牛(P<0. 05),其余各胎次间差异不显著(P>0. 05);随着胎次的增加,牛奶中体细胞数存在明显的上升趋势(P<0. 05)。中度热应激下的产奶量、高峰奶量显著低于轻度热应激(P<0. 05);中度热应激下产犊的奶牛体细胞数会稍稍偏高,但与无热应激和轻度热应激下产犊的奶牛相比差异不显著(P>0. 05);乳脂率、乳蛋白率各组差异不显著(P>0. 05)。
To investigate the effects of different parity and heat stress levels on milk production,the milk fat percentage,milk protein ratio,lipid-to-egg ratio,somatic cell count,and peak milk intake of 360 Holstein dairy cows on a dairy farm in Guangzhou area studied. The DHI data of these cows collected in the past five years were analyzed with the R ( Version 3. 3. 2) and SPSS 20. 0 software to identify the effect of different levels of parity and heat stress on milk production and milk composition. The results showed that the milk production and peak milk quantity of the first-fetal cows were lower than those of other cows ( P<0. 05). The ratio of fat to protein of the first fetal cow was significantly higher than that of the other fetal cows ( P<0. 05),and there was no significant difference among the other fetuses ( P>0. 05). With the increase of parity,there was a significant increase in the count of somatic cells in milk ( P<0. 05). The milk yield and peak milk quantity under moderate heat stress were significantly lower than those under mild heat stress ( P<0. 05). The somatic cells count of cows that underwent moderate caloric stress was slightly higher than that of the cows without calorific stress or mild heat stress ( P>0. 05). And there was no significant difference in milk fat percentage and milk protein rate among all the groups ( P>0. 05).
作者
孔令旋
雷放
邓铭
魏建生
肖帆
陈海坡
周阳
刘德武
李耀坤
KONG Lingxuan;LEI Fang;DENG Ming;WEI Jiansheng;XIAO Fan;CHEN Haipo;ZHOU Yang;LIU Dewu;LI Yaokun(College of Animal Sciences,South China Agricultural University,Guangzhou 510642,China;Zhongshan Wenshi Dairy Co.,Ltd.,Hezhou 542600,China)
出处
《畜牧与兽医》
北大核心
2019年第1期1-4,共4页
Animal Husbandry & Veterinary Medicine
基金
温氏横向研究项目(h2015657)
作者简介
孔令旋(1992-),男,硕士研究生;通信作者:李耀坤,副教授,研究方向为动物遗传育种与繁殖,E-mail:ykli@scau.edu.cn。
