Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-27T21:51:49.622Z Has data issue: false hasContentIssue false
  • English
  • Français

A new approach to the mathematical formulation of lactation curves

Published online by Cambridge University Press:  02 September 2010

S. V. Morant  and
A. Gnanasakthy
S. V. Morant
Affiliation:
Milk Marketing Board, Thames Ditton, Surrey
A. Gnanasakthy
Affiliation:
Milk Marketing Board, Thames Ditton, Surrey
Get access

Abstract

Six alternative lactation curves were derived by considering the proportional rates of change in milk yield during lactation. Experimental data showed that rates of change do not necessarily fall to a constant value in mid and late lactation. This accounts for the systematic lack of fit reported by several authors using the derivative of the incomplete gamma function, whose second derivative has a horizontal asymptote. Curves whose derivatives are not restricted in this way described patterns of milk yield in first to third lactation animals more closely. Some statistical properties of their parameters have been examined. The curve loge (y) = a - bt'(1 + kt') + ct'2 + d/t, where t is days since calving, t' = t – 150, A: is a constnat and a, b, c and d are parameters to be estimated, is recommended. This curve was also fitted to yields of milk fat, protein and lactose.

Type
Papers
Information
Animal Production , Volume 49 , Issue 2 , October 1989 , pp. 151 - 162
Copyright
Copyright © British Society of Animal Science 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Cobby, J. M. and Le Du, Y. L. P. 1978. On fitting curves to lactation data. Animal Production 26: 127–133.Google Scholar
Dhanoa, M. S. 1981. A note on an alternative form of the lactation model of Wood. Animal Production 32: 349–351.Google Scholar
Ducker, M. J., Haggett, R. A., Fisher, W. J., Morant, S. V. and Bloomfield, G. A. 1985. 1. The effect of feeding in late pregnancy and around the time of insemination on the reproductive performance of first lactation dairy heifers. Animal Production 41: 1–12.Google Scholar
Goodall, E. A. and Sprevak, D. 1984. A note on a stochastic model to describe the milk yield of a dairy cow. Animal Production 38: 133–136.Google Scholar
Rowlands, G. J., Lucey, S. and Russell, A. M. 1982. A comparison of different models of the lactation curve in dairy cattle. Animal Production 35: 135–144.Google Scholar
Wood, P. D. P. 1967. Algebraic model of the lactation curve in cattle. Nature, London 216: 164–165.CrossRefGoogle Scholar