Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-26T23:17:58.189Z Has data issue: false hasContentIssue false

An empirical model for the lactation curve of white British dairy goats

Published online by Cambridge University Press:  02 September 2010

J. C. Williams
Affiliation:
Department of Agriculture, University of Reading, Reading RG6 2AT
Get access

Abstract

A survey of dairy herds was undertaken to establish an empirical model for the goat lactation curve. The adopted model will be used to predict milk output from commercially kept dairy goats. It is also desirable for the model parameters to be easily interpretable in terms of shape and scale of the curve.

Records for 152 goat lactations from a Research Institute and 255 lactations in five commercial herds were analysed. Three groups of equations were fitted to individual goats from the Research Institute herd. The most suitable model was selected after study of residuals and consideration of the model parameters.

The adopted model was of the form: y = A exp(B(1 + n '/2)n' + Cn ‘2 – 1·01‘sol;'n) where y = daily yield in kg; n = day of lactation (post parturition); and n' = (n - 150)/100.

This model was then validated with lactation data from the five commercial herds. There was no evidence to reject the adopted model.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1993

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

Cobby, J. M. and Le Du, Y. L. P. 1978. On fitting curves to lactation data. Animal Production 26: 127133.Google Scholar
Dudouet, E. 1982. [Theoretical lactation curve of the goat and its applications.] Le Point Veterinaire 14: (68), 5361.Google Scholar
Gipson, T. A. 1989. Lactation curves in dairy goats. Ph.D. thesis, University of Illinois, Urbana, USA.CrossRefGoogle Scholar
Gipson, T. A. and Grossman, M. 1989. Diphasic analysis of lactation curves in dairy goats, journal of Dairy Science 72: 10351044.CrossRefGoogle ScholarPubMed
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: 133136.Google Scholar
Grossman, M. and Koops, W. J. 1988. Multiphasic analysis of lactation curves in dairy cattle. Journal of Dairy Science 71: 15981608.CrossRefGoogle Scholar
Ministry of Agriculture, Fisheries and Food. 1989. June 1989 agricultural census returns for England and United Kingdom. Government Statistical Service. Stats 155/89. Her Majesty's Stationery Office, London.Google Scholar
Morant, S. V. and Gnanasakthy, A. 1990. A new approach to the mathematical formulation of lactation curves. Animal Production 49:151162.Google Scholar
Neal, H. D. StC. and Thornley, J. H. M. 1983. The lactation curve in cattle: a mathematical model of the mammary gland. Journal of Agricultural Science, Cambridge 101: 389400.CrossRefGoogle Scholar
Queensborough, R. A. 1988. Lactation curves of the British Saanen goat. B.Sc. dissertation, University of Nottingham.Google Scholar
Statistical Analysis Systems Institute. 1985. SAS users guide: statistics. Version 5 edition. SAS Institute Inc., Cary, NC.Google Scholar
Wood, P. D. P. 1967. Algebraic model of the lactation curve n i cattle. Nature, London 216:164165.CrossRefGoogle Scholar
Wood, P. D. P. 1977. The biometry of lactation. Journal of Agricultural Science, Cambridge 88: 333339.CrossRefGoogle Scholar