摘要
为了研究乳房炎对奶牛产奶性能的影响,采集西安市某奶牛场618头荷斯坦奶牛完整记录的各月DHI报告中体细胞数据和兽医记录,统计分析乳房炎发病率、临床乳房炎及其患病时期对奶牛305d奶量的影响。同时另采集108头奶牛有完整记录的150个泌乳期的1 368条DHI记录,对比分析不同体细胞水平对奶牛胎次奶量、日产奶量和乳成分含量的影响。结果表明,隐性乳房炎年发病率为50.5%,临床乳房炎头阳性率为4.37%,头次阳性率为8.25%。临床乳房炎极显著降低奶牛305d奶量(P<0.01),而在泌乳盛期患病的牛305d奶量降低可达32.5%。隐性乳房炎对奶牛生产性能的影响随患病程度加重而加重,平均体细胞数>20万/mL胎次奶量就会显著减少(P<0.05),而体细胞数>50万/mL,胎次奶量极显著降低(P<0.01)。奶牛泌乳盛期患隐性乳房炎比泌乳中后期患隐性乳房炎对产奶量和乳蛋白率的影响更大,患病程度重的奶牛相对于健康牛日平均奶量显著降低(P<0.05),乳蛋白率显著增高(P<0.05),乳脂率显著降低(P<0.05)。
A complete record of the 618 Holstein cows on DHI somatic report data had been collected from a dairy farm in Xi-an, and the monthly incidence rate of subclinical mastitis and the annual incidence rate were statistically analyzed, and at the same time, according to the veterinary records, the annual positive clinical mastitis rate was counted. The paired experimental design was used to do a comparative analysis of 305 days milk of the clinical mastitis and healthy cows and the effects of clinical mastitis occurs in different stages of lactation on 305 days milk. At the same time, 1368 DHI re cords of 150 lactating periods of 108 cows were collected to do a comparative analysis of parity milk, the average daily milk production and the average milk composition content of cows with different lev els of average somatic cell count. The results show that the annual incidence rate of subclinical mastitis is 50.5% and the annual positive clinical mastitis rate is 4.37%. Clinical mastitis significantly （P〈0.01） reduced the 305 days milk , and in the peak lactation, the 305 days milk of the sick cows is 32.5% lower than that of the healthy ones. The impact of subclinical mastitis on the production performance of dairy cows increased with the increase of the disease degree, Average somatic cell count） 200 000/ml parity milk production would be a significant （P〈0.05） reduction, and somatic cell count 〉500,000/ml, parity milk was very significantly （P〈0.01） reduced. In the same parity, cows suffering from bovine subclinical mastitis during the peak lactation had a greater impact on milk yield and milk protein content than cows suffering from subclinical mastitis during the mid-and late lactation, both showed that the average daily milk of cows with serious disease significantly （P〈0.05） reduced, the rate of milk protein was significant （P〈0. 05） increased, milk fat percentage significantly （P〈0.05） reduced compared to those of healthy cows.
出处
《西北农业学报》
CSCD
北大核心
2014年第10期22-28,共7页
Acta Agriculturae Boreali-occidentalis Sinica
基金
国家十一五“863”面上项目(2008AA10Z144)
“十一五”国家科技支撑计划的项目(2006BAD04A11)
陕西省“13115”科技创新工程项目(2008ZDKG-11)
西安市科技计划项目(NC09049-2)
关键词
奶牛
乳房炎
体细胞数
生产性能
Dairy cows
Mastitis
Somatic cell count
Production performance
