Supplemental Table 1. Effects of heat stress and dietary organic acid and pure botanical supplementation on dry matter intake of weaned Holstein calves.
Description
In a completely randomized design, 62 bull and heifer calves were assigned to one of five groups during the first week of life: thermoneutral conditions (TN-Con; n = 12, 6 heifers and 6 bulls), heat stress with no organic acids and pure botanicals (OA/PB) (HS-Con; n = 12, 6 heifers and 6 bulls), thermoneutral conditions pair-fed to HS-Con (TN-PF; n = 11, 6 heifers and 5 bulls), HS with low-dose OA/PB (75 mg/kg of body weight [BW]; AviPlus R; VetAgro S.p.A., Italy; HS-Low; n = 14; 8 heifers and 6 bulls), and HS with a high-dose of OA/PB (150 mg/kg of BW; AviPlus R; HS-High; n = 13, 7 heifers and 6 bulls). Calves unsupplemented with OA/PB received a placebo containing matching dose of triglyceride. After weaning, calves (62 ± 2 d of age) were transported to a new facility where they were acclimated for 7 d in thermoneutrality (20 ± 1.7°C; 68 ± 0.4 % relative humidity; 63 ± 2 temperature-humidity index [THI]). Thereafter, calves were exposed to environmental conditions of TN (20 ± 1.3°C; 71 ± 0.3 % relative humidity; 67 ± 2 THI) or HS (32 ± 3.3°C; 41 ± 0.4 % relative humidity; 79 ± 2 THI).