Some effects of hot conditions on Brahman or Sahiwal crossbred calves

C.W. Holmes, T.P. Hughes, C.G. King, P.E.L. Sauwa and P.S.A. Auko

Department of Animal Science, Massey University, Palmerston North

Proceedings of the New Zealand Society of Animal Production. 1983, 43: 175-178

In Experiment 1, there was no difference between B x, and F calves in energy metabolism measured at about 15°C, and heat production of calves of both breeds was increased under hot conditions. At 34°C the B x calves had lower rectal temperatures and lower respiratory rates than F calves; at this high temperature, B x calves ate more and grew faster than F calves only if given a highly digestible diet (72%) but not if given a diet of lower digestibility (63%).

The B x calves also had lower rectal temperatures and respiratory rates and faster rates of sweating than F calves when exposed to a hot environment with a source of radiant heat.

When exposed to 34°C in Experiment 2, the S x calves had lower rectal temperatures and respiratory rates than the F calves; the S x calves also had slightly higher growth rates and feed intakes at this temperature.

Keywords: NZSAPAB;