Department of Veterinary Sciences, Texas Tech University, Lubbock, TX 79415 USA.
Department of Veterinary Sciences, Texas Tech University, Lubbock, TX 79415 USA; Department of Animal Science, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga, SP 13635-900, Brazil.
Vet J. 2022 Apr;282:105822. doi: 10.1016/j.tvjl.2022.105822. Epub 2022 Mar 22.
The objectives if this exploratory study were to identify variables associated with intramammary infections (IMI) during the 1st week of lactation in primiparous organic dairy cows, and to evaluate the association of those variables with somatic cell count (SCC) linear scores and milk yield in early lactation. Nulliparous cows (n = 240) were evaluated for: udder edema, teat edema, milk leakage (ML) and udder hygiene at weeks 6, 4, 2, and 1 prepartum and 1st week postpartum; body condition score (BCS) at 6 weeks prepartum and 1st week postpartum; age at calving (days), gestation length, dystocia, stillbirth, calf sex were included in the analysis. Milk samples from the 1st week postpartum were cultured using standard laboratory techniques and bacterial growth was considered IMI. Intramammary infection was observed in 58.7% of cows, with Staphylococcus chromogenes and S. aureus being the most prevalent pathogens. Cows with ML at 1st week postpartum were at 3.42 greater odds of IMI (P < 0.01). Cows with prepartum BCS ≥ 3.75 were at 3.12 greater odds of IMI (P < 0.01). Cows with ML in the 1st week of lactation had increased SCC (P < 0.01) and lower milk production in the second month of lactation (P = 0.05). Intervention studies are needed to evaluate if monitoring prepartum BCS and ML at early postpartum can aid in the control of IMIs in heifers in organic dairies.
本研究旨在确定初产有机奶牛泌乳第 1 周发生乳腺炎的相关变量，并评估这些变量与体细胞计数（SCC）线性评分和泌乳早期产奶量的相关性。对初产奶牛（n=240）进行了以下评估：产前 6 周、4 周、2 周和 1 周以及产后第 1 周的乳房水肿、乳区水肿、乳汁漏出（ML）和乳房卫生状况；产前 6 周和产后第 1 周的体况评分（BCS）；产犊日龄、胎期、难产、死胎、犊牛性别等因素均纳入分析。产后第 1 周的奶样采用标准实验室技术进行培养，细菌生长被认为是乳腺炎。58.7%的奶牛发生乳腺炎，其中金黄色葡萄球菌和金黄色葡萄球菌是最常见的病原体。产后第 1 周 ML 的奶牛发生乳腺炎的几率增加 3.42 倍（P<0.01）。产前 BCS≥3.75 的奶牛发生乳腺炎的几率增加 3.12 倍（P<0.01）。泌乳第 1 周发生 ML 的奶牛 SCC 增加（P<0.01），泌乳第 2 个月产奶量降低（P=0.05）。需要进行干预研究，以评估在产后早期监测产前 BCS 和 ML 是否有助于控制有机奶牛场青年奶牛的乳腺炎。
