Department of Animal Nutrition, Autonomous Agrarian University Antonio Narro, Saltillo, Mexico.
Department of Veterinary Medicine, Autonomous Agrarian University Antonio Narro, Torreon, Mexico.
Trop Anim Health Prod. 2021 Feb 2;53(1):149. doi: 10.1007/s11250-021-02599-1.
Tuberculosis remains a significant infectious disease of farm animals and humans worldwide. The objective of this study was to assess various risk factors associated with testing positive for bovine tuberculosis (bTB) in high-yielding Holstein cows in an intensive dry-lot dairy operation. In a retrospective observational study, 9312 records from Holstein cows from a large dairy herd in northern Mexico were used. The incidence rate of lactating cows reactor to bTB was 7.3 cases/100 cow years (95% CI = 6.7-7.9%). Multiple logistic regression models indicated that cows with total milk yield during the first lactation >10,200 kg were 1.3 times (95% confidence intervals (CI) for odds ratio (OR) = 1.2-1.6) more likely to be detected as bTB reactors than cows with total milk yield <10,200 kg (8.2 vs. 6.4%; P < 0.01). The risk of being reactor to bTB increased with x̅ total milk yield/lactation >11,500 kg (OR=2.7, 95% CI = 2.3-3.3; 10.4 vs. 4.2%) compared with cows with x̅ total milk yield/lactation <11,500 kg. Cows with >10,200 kg 305-day milk yield in the last lactation was associated (P < 0.01) with 1.3 times higher odds (95% CI for OR = 1.1-1.5) of being classed as reactors than cows with <10,200 kg. Cows with peak milk yield >48 kg were 1.9 times (95% CI for OR = 1.6-2.2) more likely to be reactor to bTB than cows with peak milk yield <48 kg (9.2 vs. 5.1%; P < 0.01). Cows with either puerperal metritis (OR = 0.07, 95% CI = 0.5-0.9) or carrying twins (OR = 0.05, 95% CI = 0.01-0.19) had a protective role for being reactor to bTB. This study showed that increased milk production was associated with a higher risk of becoming positive to tuberculin skin test in high-yielding Holstein cows.
结核病仍然是全球家畜和人类的重大传染病。本研究的目的是评估在集约化旱地奶牛场中高产荷斯坦奶牛中与牛结核病（bTB）检测呈阳性相关的各种风险因素。在一项回顾性观察研究中，使用了来自墨西哥北部一个大型奶牛场的 9312 头荷斯坦奶牛的记录。泌乳牛 bTB 反应的发病率为 7.3 例/100 头奶牛年（95%CI=6.7-7.9%）。多元逻辑回归模型表明，第一泌乳期总产奶量>10200kg 的奶牛比总产奶量<10200kg 的奶牛更有可能被检测为 bTB 反应牛，几率比为 1.3 倍（95%置信区间（CI）比值比（OR）=1.2-1.6）（8.2%比 6.4%；P<0.01）。与 x̅总泌乳期产奶量/泌乳期<11500kg 的奶牛相比，x̅总泌乳期产奶量/泌乳期>11500kg 的奶牛发生 bTB 反应的风险增加（OR=2.7，95%CI=2.3-3.3；10.4%比 4.2%）。最后一个泌乳期总产奶量>10200kg 的奶牛与 1.3 倍的几率（95%CI的 OR=1.1-1.5）相关，更有可能被归类为反应牛，而总产奶量<10200kg 的奶牛（P<0.01）。产奶量峰值>48kg 的奶牛比产奶量峰值<48kg 的奶牛更有可能成为 bTB 反应牛，几率比为 1.9 倍（95%CI的 OR=1.6-2.2）（9.2%比 5.1%；P<0.01）。患有产褥期子宫内膜炎（OR=0.07，95%CI=0.5-0.9）或怀有双胞胎（OR=0.05，95%CI=0.01-0.19）的奶牛对 bTB 反应呈阳性具有保护作用。本研究表明，在高产荷斯坦奶牛中，产奶量增加与结核菌素皮试阳性的风险增加相关。
