Comparing the responses of grain-fed feedlot cattle under moderate heat load and during subsequent recovery with those of feed-restricted thermoneutral counterparts: blood cells and inflammatory markers

• DOI: 10.1007/s00484-023-02584-3
• Publication Date: 2023-12-13T18:02:09Z
• Authors: G. Wijffels; M. L. Sullivan; S. Stockwell; S. Briscoe; R. Pearson; Y. Li; A. M. Macs; V. Sejian; R. McCulloch; J. C. W. Olm; J. Cawdell-Smith; J. B. Gaughan
• Keywords: Feedlot; Haptoglobin

Abstract Given the climate projections for livestock rearing regions globally, understanding inflammatory status of under various heat loads will be informative to animal welfare and management. A survey plasma markers was conducted, blood leucocyte counts followed investigate capacity ~ 500 kg grain fed Black Angus steer respond recover from a moderate load challenge. Two sequential cohorts 12 steers were housed in climate-controlled rooms (CCR) 18 days. thermally challenged (TC) group ( n = 2 × 6) experienced five consecutive periods: PreChallenge, Challenge, Recovery within CCR, 40 days outdoor pens (PENS Late PENS). PreChallenge (5 days) (7 delivered thermoneutral conditions, whereas Challenge TC diurnal temperature range 28–35 °C. feed-restricted (FRTN) treatment run concurrently differentiate between responses reduced feed intake alone stress. Blood neutrophil particularly sensitive with higher numbers during Challlenge PENs. The concentrations TNFα IL-1β depressed compared FRTN counterparts remained so after Challenge. Linear relationships IL-1β, IL-10, haptoglobin rumen or dry matter detected altered absent group. findings suggest significant impacts on feedlot cattle.