Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32611-0910; Department of Medicine and Preventive Medicine, College of Veterinary Medicine, University of Mosul, Mosul, Iraq 41002.
Department of Animal Sciences, University of Florida, Gainesville 32611-0910.
J Dairy Sci. 2018 Nov;101(11):10142-10150. doi: 10.3168/jds.2018-14619. Epub 2018 Aug 23.
The main objective of the study reported here was to examine the association between pregnancy loss (PL) and previous exposure to clinical or subclinical mastitis before breeding or during gestation in primiparous Holstein cows. A secondary objective was to estimate the cost of clinical mastitis during gestation, including that of PL attributable to mastitis in study cows. A total of 687 primiparous Holstein cows from 1 dairy farm were included in a matched case-control study. Study cows were declared pregnant via ultrasound on d 33 after timed artificial insemination (TAI). Case cows (n = 78) were those diagnosed as nonpregnant by rectal palpation on d 47 or 75 after TAI. Control cows were those confirmed as pregnant by rectal palpation on d 47 and 75 after TAI. Case cows were matched with eligible controls according to year of calving and calving-to-conception interval ±3 d. Cows were assigned to 1 of 3 groups: (1) cows not affected with clinical or subclinical mastitis; (2) cows affected with subclinical mastitis (Dairy Herd Improvement Association somatic cell score >4.5); and (3) cows affected with clinical mastitis during 2 exposure periods, 1 to 42 d before breeding or during gestation (1 to PL diagnosis day for case cows, and 1 to 75 d for control cows). Conditional logistic regression was used to model the odds of PL as a function of previous exposure to mastitis in study cows. Mastitis before breeding was not associated with PL. The odds of PL were 2.21 times greater in cows affected with clinical mastitis during gestation (95% confidence interval = 1.01, 4.83), compared with cows without mastitis, after controlling for breeding type and lameness. The cost of clinical mastitis during gestation was $149, which includes the cost ($27) of PL attributable to mastitis. In conclusion, this study provides evidence that clinical mastitis during gestation can cause PL in primiparous dairy cows leading to economic losses.
本研究的主要目的是检验初产荷斯坦奶牛在配种前或妊娠期间临床或亚临床乳腺炎既往暴露与妊娠丢失（PL）之间的关系。次要目的是估计妊娠期间临床乳腺炎的成本，包括研究奶牛中乳腺炎导致的 PL 的成本。在一项匹配病例对照研究中，共有来自 1 个奶牛场的 687 头初产荷斯坦奶牛被纳入研究。通过在定时人工授精（TAI）后第 33 天的超声检查，宣布研究奶牛怀孕。病例奶牛（n = 78）是指在 TAI 后第 47 天或第 75 天通过直肠触诊诊断为未怀孕的奶牛。对照组奶牛是指在 TAI 后第 47 天和第 75 天通过直肠触诊确认怀孕的奶牛。根据产犊年份和产犊至配种间隔 ±3d，将病例奶牛与合格的对照组奶牛进行匹配。奶牛被分为 3 组：（1）未患临床或亚临床乳腺炎的奶牛；（2）患亚临床乳腺炎的奶牛（奶牛群改良协会体细胞评分＞4.5）；（3）在 2 个暴露期内患临床乳腺炎的奶牛，1 至配种前 42 天或妊娠期间（病例奶牛为 1 至 PL 诊断日，对照组奶牛为 1 至 75 日）。使用条件逻辑回归模型来模拟研究奶牛既往暴露于乳腺炎与 PL 的比值比。配种前乳腺炎与 PL 无关。与未患乳腺炎的奶牛相比，在控制配种类型和跛行后，妊娠期间患临床乳腺炎的奶牛 PL 的比值比为 2.21 倍（95%置信区间为 1.01，4.83）。妊娠期间临床乳腺炎的成本为 149 美元，其中包括乳腺炎导致的 PL 的成本（27 美元）。总之，本研究提供了证据表明，妊娠期间的临床乳腺炎可导致初产奶牛发生 PL，从而导致经济损失。
