Late-gestation ear-surface temperatures and subsequent postpartum health, activity, milk yield, and reproductive performance of dairy cows

• Published in: Theriogenology 2022-03, Vol.181, p.170-179
• Main Author: Stevenson, J.S.
• Format: Article
• Language: English
• Subjects: Animals; Cattle; Dairy cow; Ear-surface temperature; Female; Health; Lactation; Milk; Postpartum Period; Pregnancy; Reproduction; Retrospective Studies; Temperature
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2022.01.022

A retrospective study was conducted to determine if postpartum health, milk yield, and reproductive traits in addition to peripartum daily physical activities (resting, eating, active time, and rumination) differ in dairy cows having greater or lesser ear-surface temperatures during late gestation (Days 230–239) compared with contemporary herd mates within season. Herd records collected from Holstein heifers (n = 348) and dry cows (n = 503; second through seventh lactations) were fitted with SensOor ear tags to collect hourly ear-surface temperatures. Mean temperatures were calculated from 240 hourly measures during Days 230–239 of gestation and cows within season were grouped into two median temperature groups. On Days 230–239 of gestation during May through September (hotter months) cows with high (H, range of 33.67–38.89 °C, mean ± SEM = 32.9 ± 0.2 °C) or medium high (MH, 25.06–31.66 °C, 29.4 ± 0.2 °C) temperatures were grouped together (n = 209 per group). For comparable gestational days during October through April (colder months), cows with medium low (ML, 17.82–25.00 °C, 21.1 ± 0.2 °C) and low (L, −0.70 to 17.80 °C, 13.4 ± 0.2 °C) temperatures were grouped together (n = 216 per group). Prepartum traits including mean ear temperature, gestation length, days in milk at dry-off, days in close-up pen, previous 305-d milk yield, proportion of heifer calves born, and cow PTA for milk differed (P