Total serum IgG concentrations were determined. Body
weight was recorded at birth and at d 15, 30, 45, and
60. Relative to CL calves, HT calves were lighter at
birth (38.3 vs. 43.1 kg), but no difference in weight
gain was observed at d 60. Additionally, HT calves had
lower apparent efficiency of IgG absorption (26.0 vs.
30.2%), but no differences were observed for total IgG
concentration. The objective of the second study was to
evaluate the isolated effect of the colostrum from HT
cows on calf immune response and growth performance.
The experimental design was identical to the first study,
but all calves were born to cows under thermoneutral