Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610; Department of Animal Reproduction, University of São Paulo, Pirassununga 13635-900, Brazil.
Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610.
J Dairy Sci. 2021 Mar;104(3):3439-3457. doi: 10.3168/jds.2020-18562. Epub 2021 Jan 15.
Automated monitoring devices (AMD) have become more affordable, and consequently more popular among dairy producers. We hypothesized that the addition of AMD-generated health alerts to a health-screening program improves survival, milk production, and reproductive success. In addition, we hypothesized that cows diagnosed with clinical disease that have AMD alerts are at greater risk of culling, lower milk production, and decreased risk of pregnancy than cows without AMD alerts. Holstein cows (nulliparous = 282, parous = 328) were enrolled at -60 ± 3 d (d 0 = calving), when they were fitted with an AMD and assigned randomly to 1 of 2 health-screening strategies: (1) control: AMD alerts not provided to farm personnel; and (2) automated device: AMD alerts provided to farm personnel. Twice daily, study personnel determined which cows had AMD alerts (health index ≤79, rumination <200 min/d, or difference between current rumination and the average of the 3 preceding days <0) and provided the information to farm personnel. Farm personnel examined cows at 3, 5, and 9 d in milk (DIM) and when daily milk yield decreased ≥25% on consecutive days. We detected no differences between health-screening strategies regarding morbidity (control = 49.7 ± 3.3%, automated device = 52.8 ± 3.2%), but the interaction between health-screening strategy and parity tended to be associated with the number of clinical diseases per cow (primiparous: control = 0.46 ± 0.06, automated device = 0.65 ± 0.07 cases/cow; multiparous: 0.88 ± 0.08, automated device = 0.86 ± 0.08 cases/cow). Cows enrolled in the automated device strategy were more likely to be treated with supportive therapy (64.4 ± 3.1 vs. 55.0 ± 3.2%), whereas primiparous cows in the automated device strategy were more likely to be treated with anti-inflammatory drugs than those in the control strategy (41.6 ± 4.7 vs. 23.8 ± 4.0%). Health-screening strategy did not affect survival or total milk yield up to 22 wk postpartum, but cows in the automated device strategy had reduced risk of pregnancy after the first 2 services (54.5 ± 3.0 vs. 46.2 ± 3.2%). Cows diagnosed with a clinical disease without AMD alerts had reduced risk of removal from the herd by 150 DIM (5.7 ± 2.0 vs. 19.0 ± 3.3%), greater risk of pregnancy after the first 2 services (49.6 ± 4.5 vs. 33.6 ± 3.9%), and greater milk by 22 wk postpartum (6.7 ± 0.2 vs. 5.3 ± 0.2 × 10 kg) than cows diagnosed with a clinical disease that had an AMD alert. Adding AMD-generated health alerts to the health screening of postpartum cows in a herd with an existing screening program did not improve survival, milk yield, or reproductive success. In addition, AMD alerts in cows diagnosed with a clinical disease may be indicative of the future success of such cows.
自动化监测设备（AMD）变得更加实惠，因此在奶牛生产者中越来越受欢迎。我们假设，将 AMD 生成的健康警报添加到健康筛查计划中可以提高奶牛的存活率、产奶量和繁殖成功率。此外，我们假设，被诊断患有临床疾病且有 AMD 警报的奶牛，其淘汰率、产奶量较低，且怀孕的风险降低，而非 AMD 警报的奶牛则没有。荷斯坦奶牛（初产=282 头，经产=328 头）在-60±3 d（d0=产犊）时被招募，当时它们被安装了 AMD 并随机分配到 2 种健康筛查策略之一：（1）对照组：不向农场人员提供 AMD 警报；（2）自动化设备组：向农场人员提供 AMD 警报。研究人员每天两次确定哪些奶牛有 AMD 警报（健康指数≤79、反刍<200 min/d 或当前反刍与前 3 天平均值的差值<0），并将信息提供给农场人员。农场人员在产犊后第 3、5 和 9 天（DIM）以及连续几天产奶量下降≥25%时检查奶牛。我们在发病率方面未检测到健康筛查策略之间的差异（对照组=49.7±3.3%，自动化设备组=52.8±3.2%），但健康筛查策略与胎次之间的交互作用似乎与每头奶牛的临床疾病数量有关（初产：对照组=0.46±0.06，自动化设备组=0.65±0.07 例/头；经产：0.88±0.08，自动化设备组=0.86±0.08 例/头）。参加自动化设备策略的奶牛更有可能接受支持性治疗（64.4±3.1%对 55.0±3.2%），而自动化设备策略中的初产奶牛更有可能接受抗炎药物治疗，而不是对照组（41.6±4.7%对 23.8±4.0%）。健康筛查策略不影响产后 22 周的存活率或总产奶量，但在第 1 次和第 2 次服务后，自动化设备策略中的奶牛怀孕的风险降低（54.5±3.0%对 46.2±3.2%）。在没有 AMD 警报的情况下被诊断为临床疾病的奶牛，在 150 DIM 时被淘汰的风险降低了 15%（5.7±2.0%对 19.0±3.3%），在第 1 次和第 2 次服务后怀孕的风险更高（49.6±4.5%对 33.6±3.9%），产后 22 周产奶量更高（6.7±0.2 对 5.3±0.2×10 kg），而被诊断为患有临床疾病且有 AMD 警报的奶牛则没有。在一个已有筛查计划的牛群中，将 AMD 生成的健康警报添加到产后奶牛的健康筛查中，并没有提高奶牛的存活率、产奶量或繁殖成功率。此外，在被诊断患有临床疾病的奶牛中，AMD 警报可能预示着这些奶牛未来的成功。
