Oliver S P, Lewis M J, Gillespie B E, Dowlen H H
Department of Animal Science, University of Tennessee, Knoxville 37996, USA.
Zentralbl Veterinarmed B. 1997 Jun;44(4):213-20. doi: 10.1111/j.1439-0450.1997.tb00967.x.
The present study was conducted to determine if antibiotic treatment of heifer mammary glands earlier in the prepartum period reduced the occurrence of residues in milk without compromising efficacy in treatment of intramammary infections. Heifers were assigned randomly to two groups: 1. untreated negative control (n = 42); and 2. intramammary infusion of 200 mg cephapirin sodium (n = 40) 14 days prior to expected calving. Mammary secretions were collected before treatment and during early lactation, and were analyzed for residues by the Bacillus stearothermophilus disc assay. Only four of 127 samples (3.1%) obtained from cephapirin-treated mammary glands at 3 days after calving were positive for residues and most (three of four) were from a heifer that calved within 3 days of treatment. Mammary secretions were also collected before treatment, and at 3 and 30 days after calving for microbiological evaluation. For untreated control heifers, mastitis pathogens were isolated from 67.3% of samples obtained from mammary glands 14 days prior to expected calving, 55.6% obtained 3 days after calving and 36.4% of samples obtained 30 days postpartum. A similar percentage of samples (63.8%) was positive for mastitis pathogens at 14 days before expected calving prior to antibiotic treatment. However, only 15.1% of samples obtained at 3 days after calving and 7.9% of samples obtained 30 days postpartum from mammary glands of antibiotic-treated heifers contained mastitis pathogens. Coagulase-negative staphylococci were isolated most frequently. Intramammary infusion of antibiotics earlier in the prepartum period markedly reduced the occurrence of residues in milk during early lactation without affecting efficacy.
本研究旨在确定在产前早期对小母牛乳腺进行抗生素治疗是否能减少牛奶中残留的发生，同时不影响乳腺内感染的治疗效果。小母牛被随机分为两组：1. 未治疗的阴性对照组（n = 42）；2. 在预期产犊前14天进行乳腺内注入200毫克头孢匹林钠（n = 40）。在治疗前和泌乳早期收集乳腺分泌物，并通过嗜热脂肪芽孢杆菌纸片法分析残留情况。在产犊后3天从接受头孢匹林治疗的乳腺中获得的127个样本中，只有4个（3.1%）残留呈阳性，且大多数（4个中的3个）来自在治疗后3天内产犊的小母牛。在治疗前、产犊后3天和30天也收集乳腺分泌物进行微生物学评估。对于未治疗的对照小母牛，在预期产犊前14天从乳腺获得的样本中，67.3%分离出乳腺炎病原体，产犊后3天获得的样本中55.6%分离出乳腺炎病原体，产后30天获得的样本中36.4%分离出乳腺炎病原体。在抗生素治疗前预期产犊前14天，类似比例（63.8%）的样本乳腺炎病原体呈阳性。然而，在产犊后3天从接受抗生素治疗的小母牛乳腺获得的样本中，只有15.1%含有乳腺炎病原体，产后30天获得的样本中7.9%含有乳腺炎病原体。凝固酶阴性葡萄球菌分离最为频繁。在产前早期进行乳腺内抗生素注入可显著减少泌乳早期牛奶中残留的发生，且不影响疗效。
