Cattle Twins: The maternal environment and animal production

P.J. Brumby

Ruakura Animal Research Station, Hamilton

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Proceedings of the New Zealand Society of Animal Production. 1960, 20: 95-107

Using data derived from field records, estimates of the contribution of the maternal environment (m2) to the variation in lactation records indicated that approximately 10 per cent. of the total within-herd variation in milk and butterfat yield could be attributed to this source of variation.

The low environmental variance encountered in monozygous twin records is discussed in relation to this result. It is pointed out that even with the variance, (m²), added to the variance within monozygous pairs, the total is still markedly less than that derived from half-sib data.

It is postulated that the low within set variance in monozygous pairs originates because the genotype will, in part, determine the environmental variance associated with it.

The contribution of the maternal environment to growth is noted and illustrated by reference to mice growth data.

The nature of the possible differences in the maternal environment is noted and results quoted indicating a possible cytoplasmic influence on growth in mice.

The importance of the variation found in the maternal environment is discussed in relation to selection experiments, and the value of the technique of ova transplantation in interpreting genetic problems is stressed.

Keywords: NZSAPAB;

Last Updated 24-08-2000