Borm A A, Fox L K, Leslie K E, Hogan J S, Andrew S M, Moyes K M, Oliver S P, Schukken Y H, Hancock D D, Gaskins C T, Owens W E, Norman C
Department of Animal Sciences, Washington State University, Pullman 99164, USA.
J Dairy Sci. 2006 Jun;89(6):2090-8. doi: 10.3168/jds.S0022-0302(06)72279-2.
Preparturient heifers (n = 561) from 9 herds in 6 US states and 1 Canadian province were enrolled in a study to test the hypothesis that prepartum intramammary therapy would cure existing intramammary infections (IMI) and lead to increased milk production, reduced linear somatic cell count (LSCC), and improved reproductive performance. Mammary secretions were collected 10 to 21 d before expected calving from each quarter. Heifers were then assigned by identification number to receive intramammary therapy consisting of infusion of one tube per mammary quarter of a lactating cow commercial antibiotic preparation containing cephapirin or to a nontreated control group. Overall, 34.1% of mammary quarters were infected with a mastitis pathogen before parturition and 63.4% of heifers had at least one mammary quarter infected. The coagulase-negative staphylococci (CNS) caused the majority (74.8%) of prepartum IMI. Coagulase-positive staphylococci, environmental streptococci, and coliforms accounted for 24.5% of prepartum infections. Treatment had a significant effect on the cure rate of infected mammary quarters. Mammary quarters that were infected prepartum and treated with antibiotics had a 59.5% efficacy of cure rate and the percentage reduction in heifers with IMI was 51.9. Control quarters had a spontaneous cure rate of 31.7%. Treatment did not significantly affect milk production or LSCC in the first 200 d of lactation; however, there was a significant treatment by herd interaction for milk production. Quarters cured of either CNS or major pathogens had a lower LSCC in the first 200 d of lactation. No significant effect on services per conception or days open between treatment and control groups was observed. This trial demonstrated that prepartum intramammary antibiotic therapy did reduce the number of heifer IMI postpartum. Milk production, LSCC, and reproductive performance during the first 200 d of the first lactation were not significantly affected by treatment. Given these results, use of prepartum intramammary antibiotic therapy in heifers as a universal strategy to increase milk production in first-lactation dairy cows may not be warranted.
来自美国6个州和加拿大1个省的9个牛群的561头产前小母牛参与了一项研究，以检验以下假设：产前乳房内治疗可治愈现有的乳房内感染（IMI），并提高产奶量、降低线性体细胞计数（LSCC）以及改善繁殖性能。在预计产犊前10至21天从每个乳区采集乳汁分泌物。然后根据识别号将小母牛分配至接受乳房内治疗组，即每个乳区注入一管含头孢匹林的泌乳奶牛商用抗生素制剂，或分配至未治疗的对照组。总体而言，34.1%的乳区在分娩前感染了乳腺炎病原体，63.4%的小母牛至少有一个乳区被感染。凝固酶阴性葡萄球菌（CNS）导致了大多数（74.8%）的产前IMI。凝固酶阳性葡萄球菌、环境链球菌和大肠菌群占产前感染的24.5%。治疗对感染乳区的治愈率有显著影响。产前感染并用抗生素治疗的乳区治愈率为59.5%，IMI小母牛的减少百分比为51.9。对照乳区的自发治愈率为31.7%。治疗在泌乳的前200天对产奶量或LSCC没有显著影响；然而，产奶量存在显著的畜群与治疗交互作用。治愈CNS或主要病原体的乳区在泌乳的前200天LSCC较低。未观察到治疗组和对照组在每次受孕的配种次数或空怀天数上有显著差异。该试验表明，产前乳房内抗生素治疗确实减少了产后小母牛IMI的数量。治疗对第一个泌乳期前200天的产奶量、LSCC和繁殖性能没有显著影响。鉴于这些结果，将产前乳房内抗生素治疗作为提高初产奶牛产奶量的通用策略应用于小母牛可能并不合理。
