Hostname: page-component-7c8c6479df-7qhmt Total loading time: 0 Render date: 2024-03-28T10:10:37.632Z Has data issue: false hasContentIssue false

Milk protein precursors in lactating goats

Published online by Cambridge University Press:  24 November 2017

B J. Bequette
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
C. Backwell
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
G.E. Lobley
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
J.C. MacRae
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
Get access

Extract

With the failure of current nutritional schemes for dairy ruminants to predict yields of milk and milk components, and perceptions of milk's nutritional value following recommendations to reduce dietary fat intake, an integrated approach to feeding and metabolism needs to be developed. Such a system must therefore be ‘metabolite’ based.

An ability to predict changes in milk constituent output in response to alterations in nutrition requires, in the first instance, the identification of specific precursors for milk component synthesis in the lactating mammary gland. Arteriovenous differences across the mammary gland indicate that blood free amino acids (AA) are either taken-up by the gland in excess, equal to, or in insufficient amounts compared to their output in milk (1). Isotope labelling experiments have indicated that, in addition to AA free in blood, the mammary gland utilises a substantial amount of AA derived from constitutive mammary gland protein breakdown (2). The present experiment was designed to investigate the AA precursors and kinetics of milk protein synthesis and to confirm and extend the latter observations.

Type
Ruminant Nutrition
Copyright
Copyright © The British Society of Animal Production 1992

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

(1) Metcalf, J.A., Beever, D.E., Sutton, J.D. and Humphries, D.J. (1992) Protein utilisation by the mammary gland in lactating dairy cows. BSAP, Winter Meetings (previous paper).Google Scholar
(2) Oddy, V.H., Lindsay, D.B. and Fleet, I.R. (1988) Protein synthesis and degradation in the mammary gland of lactating goats. J. Dairy Res. 55, 143154.Google Scholar
(3) AFRC (1984). In: Report of the Protein Group of the Agricultural Research Council Working Party on the Nutrient Requirements of Ruminants - Supplementary Report to Chapter 4 (ARC 1980); Famham Common: Commonwealth Agricultural Bureaux.Google Scholar