Pankey J W, Pankey P B, Barker R M, Williamson J H, Woolford M W
Department of Animal and Food Sciences, University of Vermont, Burlington 05473, USA.
N Z Vet J. 1996 Apr;44(2):41-4. doi: 10.1080/00480169.1996.35932.
The objective of the study was to determine the prevalence of mastitis among primiparous heifers at calving and at drying off in 11 Waikato dairy herds during the 1993-94 dairy production season. Duplicate quarter milk samples were collected aseptically from 458 heifers within 5 days after calving for bacteriological analysis. Mastitis was diagnosed in at least one quarter in 35.6% of these heifers. Coagulase-negative staphylococci were isolated from 21.8% of the heifers. The prevalence of coagulase-negative staphylococci varied between herds from 4.3% to 44.8%. Environmental streptococci caused mastitis in 12.2% of heifers, ranging from 5.6% to 24.1% between herds. Streptococcus uberus was the pathogen identified most frequently at calving and accounted for more than 90% of the streptococcal isolates. Staphylococcus aureus and coliforms were isolated from less than 1% of samples. Clinical mastitis was observed in 8.1% of heifers at calving; environmental streptococci were isolated from 67.6% of these clinical clinical cases. Only 2.8% of heifers developed clinical mastitis during lactation and environmental streptococci were isolated from 38.5% of these cases. The prevalence of mastitis among 428 of the heifers at drying off was 64.7%; a 1.8 fold increase during lactation. Corynebactetium bovis was isolated from 43% of heifers at drying off even though it was not isolated from any heifers at calving. During the season, the prevalence of Staphylococcus aureus mastitis increased to 2.8% while mastitis caused by environmental streptococci declined to 2.8%. The prevalence of environmental mastitis pathogens decreased during lactation while contagious pathogens increased in each of the 11 herds. Ineffective post-milking teat sanitation probably contributed to the increase in mastitis caused by contagious pathogens. Specific factors were not determined that affected the variation in prevalence between herds.
本研究的目的是确定1993 - 1994年奶牛生产季节期间，11个怀卡托奶牛场初产小母牛在产犊时和干奶期的乳腺炎患病率。在产犊后5天内，从458头小母牛身上无菌采集重复的四分位牛奶样本进行细菌学分析。在这些小母牛中，35.6%的小母牛至少有一个乳房象限被诊断为乳腺炎。从21.8%的小母牛中分离出凝固酶阴性葡萄球菌。各牛场中凝固酶阴性葡萄球菌的患病率在4.3%至44.8%之间。环境链球菌导致12.2%的小母牛患乳腺炎，各牛场之间的患病率在5.6%至24.1%之间。乳房链球菌是产犊时最常鉴定出的病原体，占链球菌分离株的90%以上。从不到1%的样本中分离出金黄色葡萄球菌和大肠菌群。8.1%的小母牛在产犊时出现临床乳腺炎；这些临床病例中有67.6%分离出环境链球菌。只有2.8%的小母牛在泌乳期发生临床乳腺炎，这些病例中有38.5%分离出环境链球菌。428头小母牛在干奶期的乳腺炎患病率为64.7%；泌乳期增加了1.8倍。即使在产犊时未从任何小母牛中分离出牛棒状杆菌，但在干奶期从43%的小母牛中分离出了该菌。在该季节，金黄色葡萄球菌乳腺炎的患病率增加到2.8%，而环境链球菌引起的乳腺炎患病率下降到2.8%。在11个牛场中，泌乳期环境乳腺炎病原体的患病率下降，而传染性病原体增加。挤奶后乳头卫生措施无效可能导致了传染性病原体引起的乳腺炎增加。未确定影响各牛场患病率差异的具体因素。
