中牟县某奶牛场奶牛乳房炎的发生规律分析

A case study of occurrence of mastitis in cows on a dairy farm

为了掌握奶牛乳房炎的发生规律,通过对河南省中牟县某奶牛场随机抽样500头奶牛的乳房炎检测,获得临床型和隐性型乳房炎的一系列相关数据,并对奶牛乳房炎的发生与胎次、月份、泌乳时期、分娩头数、乳区、日产奶量等之间的关系进行统计分析。结果显示：各胎次之间奶牛乳房炎发生存在极显著差异（P〈0.01）,胎次与总阳性率、临床阳性率、隐性阳性率之间的相关系数分别为0.826 8（P〈0.01）、0.928 8（P〈0.01）、0.663 8（P〉0.05）;各月份之间奶牛乳房炎发生率差异显著（P〈0.05）;而临床型与隐性型间差异极显著（P〈0.01）,二者之间的相关系数为0.992 6（P〈0.01）;随着泌乳时期延长奶牛乳房炎发生率有增高的趋势,且二者间具有极显著的相关性（P〈0.01）;各月份的分娩头数与临床型、隐性型乳房炎间的相关系数分别为0.858 6（P〈0.01）、0.862 6（P〈0.01）;4个乳区乳房炎发生率差异不显著（P〉0.05）,前后乳区间、左右乳区间也差异不显著（P〉0.05）;日产奶量4个水平之间阳性率差异不显著（P〉0.05）,而日产奶量与总阳性率、临床阳性率、隐性阳性率间的相关系数分别为-0.961 9、-0.910 4、-0.946 5,三者均极显著（P〈0.01）。本研究结果可为有效防治奶牛乳房炎疾病提供参考。

In order to identify the law of occurrence of mastitis in dairy cows. 500 cows on a dairy farm in Zhongmu County of Henan Province were randomly sampled,and a series of related data of clinical and recessive mastitis were obtained. Then,the relationships between the occurrence of mastitis and various factors,including parity,months,lactating period,number of calves delivered,breast area and daily milk yield,were analyzed. The results obtained were that the parity between the occurrences of mastitis in dairy cows was significantly different（ P0. 01）. The correlation coefficients between parity and total positive rate,clinical positive rate,recessive positive rate were 0. 826 8（ P0. 01）,0. 928 8（ P0. 01）,and 0. 663 8（ P0. 05） respectively. The incidences of mastitis among cows in each month（ P 0. 05） were significantly different,and the difference was highly significant between clinical and recessive types（ P 0. 01）. The correlation coefficients between the number of deliveries in each month and clinical mastitis and subclinical mastitis were 0. 858 6（ P 0. 01） and 0. 862 6（ P 0. 01） respectively. However,there was no significant difference in the incidence of mastitis between the four breast areas（ P 0. 05）,between the anterior mammary region and the posterior mammary region,between the left and right milk areas（ P0. 05）,and between the four levels of positive rate of daily milk yield（ P0. 05）. The correlation coefficients between daily milk yield and the total positive rate,clinical positive rate and occult positive rate were -0. 961 9,-0. 910 4 and -0. 946 5 respectively,all with high significance（ P0. 01）. The results here may be used as references for effective prevention and treatment of mastitis in dairy cows.