Influence of birth date and dam's age on early growth in beef cattle

R.L. Baker, A.H. Carter, E.H. Cox and H.A. Templer

Ruakura Agricultural Research Centre, Hamilton

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Proceedings of the New Zealand Society of Animal Production. 1974, 34: 115-130

This paper reports age of dam, sex and regression-on-age effects for calf liveweight data from birth to 12 months of age or older from two experimental beef breeding locations. The magnitudes of all effects varied significantly both over years and between locations. Age-of-dam effects declined with calf age but remained important through to 18 to 20 months. Age-regression coefficients were consistently higher for males than females. The results are discussed in relation to current methods of correcting weaning and yearling weights for age of dam and birth date used by the NZ National beef Recording Scheme (BeefPlan). It is concluded that present methods require re-examination, and in particular that correction factors should be calculated separately for each herd-year wherever adequate data are available.

Keywords: NZSAPAB;

Last Updated 24-08-2000