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A note on the use of a categorical variable to explain seasonality deviation from the lactation curve

Published online by Cambridge University Press:  02 September 2010

E. A. Goodall
Affiliation:
Department of Agriculture for Northern Ireland, Newforge Lane, Belfast BT9 5PX
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Abstract

The addition of a categorical variable to the lactation model of Wood (1967) has been shown to be useful in the explanation of seasonality of milk production using data from an experimental herd. The technique is further investigated using monthly milk-yield data from 43 commercial herds in Northern Ireland in the years 1978 to 1982. Coefficients, d, of the categorical variable were estimated for each month of calving. The maximum value of d was 0·256 for the month of October and the minimum value was 0·022 for the month of March.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1986

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References

REFERENCES

Goodall, E. A. 1983. An analysis of seasonality of milk production. Anim. Prod. 36: 6972.Google Scholar
Goodall, E. A. and Sprevak, D. 1985. A Bayesian estimation of the lactation curve of the dairy cow. Anim. Prod. 40: 189193.Google Scholar
Wood, P. D. P. 1967. Algebraic model of the lactation curve in cattle. Nature, Land. 216: 164165.CrossRefGoogle Scholar
Wood, P. D. P. 1981. A note on regional variations in the seasonality of milk production in dairy cattle. Anim. Prod. 32: 105108.Google Scholar