HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gibson, J. P. Search for Related Content PubMed Articles by Gibson, J. P.

Selection on the Major Components of Milk: Alternative Methods of Deriving Economic Weights

Centre for Genetic Improvement of Livestock, Department of Animal and Poultry Science, University of Guelph, Ontario, N1G 2W1, Canada

ABSTRACT

Selection indexes for milk components in the published literature have been derived from economic weights that suffered from several inadequacies: 1) they failed to include the majority of costs, 2) they were based on payment systems without first demonstrating long-term stability, 3) they employed average, not marginal, costs and returns, and 4) they used no rescaling to allow for alternative methods of increasing outputs. Alternative methods of deriving economic weights are presented for both a free market and a protected market. The various methods are used to derive economic weights for the major components of milk (fat, protein, and lactose) in the Canadian dairy industry. Different methods produce widely different absolute and relative economic weights. The inclusion of all costs and rescaling to fixed output appear to be important. If an existing protected market for dairy products has long-term stability, the relationship between production and returns is discontinuous. This is because once the internal market is satisfied, excess production is sold to external markets at a markedly lower, sometimes negative price. In this case the use of marginal as opposed to average costs and returns is important, particularly for fat and protein. The information gained in a rational approach to defining economic weights could be used in defining future payment systems that would promote breeding objectives at the farm level, which would be sensible for the industry as a whole.

This article has been cited by other articles:

				G. E. Shook Major advances in determining appropriate selection goals. J Dairy Sci, April 1, 2006; 89(4): 1349 - 1361. [Abstract] [Full Text] [PDF]