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Algebraic models of the lactation curves for milk, fat and protein production, with estimates of seasonal variation

Published online by Cambridge University Press:  02 September 2010

P. D. P. Wood
P. D. P. Wood
Affiliation:
Milk Marketing Board, Thames Ditton, Surrey
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Summary

The lactation curves of whole milk production and of compositional quality measures may be represented by one of a family of curves

where the coefficients a, b and c define the curve of production of a character y at week n.

An analysis of protein results from over 600 000 cows, and of fat results from nearly 3000 cows gave shape coefficients (b, c) for fat percentage (-0·1316, 0·0154) and for protein percentage (-0·1223, 0·0109) showing that the lowest percentage of each occurred during weeks 8 and 11 of lactation respectively.

Seasonal variations were calculated to show an expected deficiency of 0·93% fat in the spring and 0·75% protein in winter, which could be attributed to environmental influences associated with varying feeding standards.

Type
Research Article
Information
Animal Production , Volume 22 , Issue 1 , February 1976 , pp. 35 - 40
Copyright
Copyright © British Society of Animal Science 1976

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References

Broster, W. H., Broster, V. J., Smith, T. and Siviter, J. W. 1975. Experiments on the nutrition of the dairy heifer. J. agric. Sci., Camb. 84: 173–186.CrossRefGoogle Scholar
Milk Marketing Board. 1972a. The use of herd management control. Rep. Breed. Prod. Org. Milk Mktg Bd, No. 22, pp. 35–37.Google Scholar
Milk Marketing Board. 1972b. The practical application of the lactation curve equation. Rep. Breed. Prod. Org. Milk Mktg Bd, No. 22, pp. 83–93.Google Scholar
Wood, P. D. P. 1967. Algebraic model of the lactation curve in cattle. Nature, Lond. 216: 164–165.CrossRefGoogle Scholar
Wood, P. D. P. 1968. Factors affecting persistency of lactation in cattle. Nature, Lond. 218: 894.CrossRefGoogle Scholar
Wood, P. D. P. 1969. Factors affecting the shape of the lactation curve in cattle. Anim. Prod. 11: 307–316.Google Scholar
Wood, P. D. P. 1970. A note on the repeatability of parameters of the lactation curve in cattle. Anim. Prod. 12: 535–538.Google Scholar
Wood, P. D. P. 1972. A note on seasonal fluctuations in milk production. Anim. Prod. 15: 89–92.Google Scholar