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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

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