The Open UniversitySkip to content
 

Pre-pubertal measurements of the somatotrophic axis as predictors of milk production in Holstein-Friesian dairy cows

Taylor, V. J.; Beever, D. E.; Bryant, M. J. and Wathes, D. C. (2006). Pre-pubertal measurements of the somatotrophic axis as predictors of milk production in Holstein-Friesian dairy cows. Domestic Animal Endocrinology, 31(1) pp. 1–18.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1016/j.domaniend.2005.08.002
Google Scholar: Look up in Google Scholar

Abstract

This study investigated possible relationships between measurements of the somatotrophic axis in pre-pubertal dairy calves and subsequent milk yields. Endogenous growth hormone (GH) release was measured through a fed and fasted period in fifty 6-month-old Holstein-Friesian heifers and they were then challenged with growth hormone-releasing factor (GRF) to assess their GH release pattern. Insulin-like growth factor-I (IGF-I), insulin and glucose concentrations were measured in relation to time of feeding. Cows were subsequently monitored through their first three lactations to record peak and 305-day milk yields. In the first lactation, milk energy output for the first 120 days of lactation was also calculated. The mean 305-day milk yield increased from 7417 +/- 191 kg in the first lactation (n = 37) to 8749 +/- 252 kg in the third (n = 25). There were no significant relationships between any measures of GH secretion and peak or 305-day yield in any lactation. A highly significant positive relationship was established between the GH peak measured 10 min post-GRF challenge and 120-day milk energy values in the first lactation. This relationship was, however, only present in the subpopulation of 12 cows culled after one or two lactations and was absent in the 25 animals remaining for the third lactation. There were no significant relationships between pre-pubertal IGF-I and fed or fasted insulin or glucose concentrations and any subsequent measurement of yield. The usefulness of GH secretagogue challenges in calves as a predictive test for future milk production is thus limited but may have some bearing on nutrient partitioning and longevity. (c) 2005 Elsevier Inc. All rights reserved.

Item Type: Journal Article
ISSN: 0739-7240
Keywords: growth hormone secretion; factor-I; domestic animals; nutritional regulation; metablolic challenges; bovine somatotropin; energy balance; mammary tissue; IGF-I; insulin
Academic Unit/Department: Science > Life, Health and Chemical Sciences
Interdisciplinary Research Centre: Biomedical Research Network (BRN)
Item ID: 6710
Depositing User: Astrid Peterkin
Date Deposited: 14 Feb 2007
Last Modified: 10 Mar 2014 09:31
URI: http://oro.open.ac.uk/id/eprint/6710
Share this page:

Altmetrics

Scopus Citations

Actions (login may be required)

View Item
Report issue / request change

Policies | Disclaimer

© The Open University   + 44 (0)870 333 4340   general-enquiries@open.ac.uk