Laven R A, Lawrence K E
Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
N Z Vet J. 2008 Aug;56(4):171-5. doi: 10.1080/00480169.2008.36830.
To evaluate the benefit of blanket treatment of all milking cows at drying-off and all replacement heifers one month prior to the planned start of mating with an internal teat sealant on the incidence of mastitis, and somatic cell counts (SCC), postpartum in a 650-cow herd with a mastitis incidence in early lactation of 15% in cows and 26% in heifers.
Prior to drying-off, lactating cattle were divided on the basis of SCC and mastitis history. Cattle with records of individual SCC >150,000 cells/ml or mastitis in the previous lactation were treated with a cloxacillin-based dry-cow therapy (DCT), while the remaining cattle received no antibiotics. Cattle in each of the two groups were then randomly assigned to receive either an internal teat sealant or no further treatment. Additionally, one month prior to the planned start of calving the rising 2-year-old heifers were also randomly assigned to receive either an internal teat sealant or no treatment. All clinical mastitis cases were recorded for the first 10 weeks after the start of calving, while SCC were measured on three occasions during the subsequent lactation.
Data were available from 466 cows and 206 heifers; treatment with the internal teat sealant significantly reduced the incidence of mastitis in both groups. For cows, the reduced risk of mastitis due to treatment with the teat sealant was not significantly different between cows, which, based on their mastitis history, required dry-cow antibiotics and those which did not. There was no effect of teat sealant on the mean SCC of any group at any time-point.
On this farm, treatment of all cows and heifers prior to parturition with an internal teat sealant significantly reduced the risk of clinical mastitis. The benefits of an internal teat sealant were the same when used in combination with antibiotics in cows with a history of mastitis as when used alone in cows with no such history.
These data support the proposition that blanket treatment with an internal teat sealant of all cows due to enter the milking herd can be a useful method of mastitis control. They also suggest that combined therapy with dry-cow antibiotics and internal teat sealants can be beneficial under New Zealand conditions. More detailed research on more farms in more areas of New Zealand is required to confirm these suggestions.
评估在一个拥有650头奶牛的牛群中，对所有干奶期的泌乳奶牛以及计划配种前一个月的所有后备小母牛使用内部乳头封闭剂进行全面处理，对乳腺炎发病率和体细胞计数（SCC）的影响。该牛群中，奶牛在泌乳早期的乳腺炎发病率为15%，小母牛为26%。
在干奶前，根据体细胞计数和乳腺炎病史对泌乳牛进行分组。个体体细胞计数>150,000个/毫升或在上一个泌乳期患过乳腺炎的牛，采用基于氯唑西林的干奶牛疗法（DCT）进行治疗，其余牛不使用抗生素。然后，将两组中的牛随机分配接受内部乳头封闭剂处理或不进行进一步处理。此外，在计划产犊前一个月，即将满2岁的后备小母牛也随机分配接受内部乳头封闭剂处理或不进行处理。记录产犊后前10周内所有临床乳腺炎病例，同时在随后的泌乳期内三次测量体细胞计数。
获得了466头奶牛和206头小母牛的数据；使用内部乳头封闭剂进行处理显著降低了两组的乳腺炎发病率。对于奶牛，基于乳腺炎病史需要干奶牛抗生素治疗的奶牛和不需要的奶牛，使用乳头封闭剂治疗降低乳腺炎风险的效果没有显著差异。在任何时间点，乳头封闭剂对任何组的平均体细胞计数均无影响。
在这个农场，在分娩前对所有奶牛和小母牛使用内部乳头封闭剂进行处理显著降低了临床乳腺炎的风险。对于有乳腺炎病史的奶牛，将内部乳头封闭剂与抗生素联合使用的效果与对无此类病史的奶牛单独使用的效果相同。
这些数据支持以下观点，即对所有即将进入泌乳牛群的奶牛使用内部乳头封闭剂进行全面处理可能是一种控制乳腺炎的有效方法。它们还表明，在新西兰的条件下，干奶牛抗生素和内部乳头封闭剂联合治疗可能有益。需要在新西兰更多地区的更多农场进行更详细的研究来证实这些建议。
