Growth rate and oestrous behaviour of Friesian, Hereford x Friesian, Simmental x Friesian and Angus heifers

D.C. Dalton, K.E. Jury and D.R.H. Hall

Whatawhata Hill Country Research Station, Hamilton

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Proceedings of the New Zealand Society of Animal Production. 1975, 35: 129-136

Friesian (F x F), Hereford x Friesian (H x F) and Simmental x Friesian (S x F) heifer calves were bred and reared on 21 farms up to weaning at 4 months of age. They were then grazed together at one location, where growth and oestrous data were recorded until joining with entire bulls at 14 months of age.

The F x F heifers showed superior growth, followed by the S x F and H x F heifers. The percentage of animals exhibiting first oestrus by 14 months of age was 85, 60 and 44 for the F x F, H x F and S x F, respectively. Angus (A x A) heifers which joined the trial after single suckling to 6 months of age showed lower post-weaning growth than the other breeds.

Between breeds, there were no differences in age and weight at first oestrus of heifers which cycled, but those heifers which did not cycle were 23 kg lighter and 7 days younger than those showing oestrus.

Significant sire differences within breeds were found in the weight-for-age of their progeny, indicating potential for improvement through selection.

The pre-weaning environment exerted a highly significant effect on subsequent growth of the heifers with no compensatory growth shown by poorly reared calves.

Keywords: NZSAPAB;

Last Updated 24-08-2000