Animal Science Abstract
Effects of age on plasma metabolites and hormones in finishing Belgian Blue double-muscled cull females
J. -F. Cabaraux1,A, I. Dufrasne2, L. Istasse1 and J. -L. Hornick1
AE-mail: jfcabaraux@ulg.ac.be
1Nutrition Unit, B43, Department of Animal Production, Faculty of Veterinary Medicine, University of Liège, Sart-Tilman, 4000 Liège, Belgium2Experimental Station, B39, Department of Animal Production, Faculty of Veterinary Medicine, University of Liège, Sart-Tilman, 4000 Liège, Belgium
Abstract
Two groups of 12 Belgian Blue double-muscled cull females were used successively in a 2-year repeated experiment and divided into three groups according to age, allowing four animals per group each year. The aim of the trial was to relate, during the finishing period, the metabolic and endocrine parameters with age. Females were fattened with a diet based on maize silage and were blood sampled on several occasions. The average daily gain (ADG) decreased with the age of the cows. Plasma glucose and triglycerides decreased also with age while the youngest females showed lower concentrations of urea than those older. The composition of plasma non-esterified fatty acids also differed considerably between groups. The hormones that best related with ADG were IGF-1 and insulin. Plasma concentrations of thyroid hormones were lower in the oldest animals. No difference between groups was found for GH. Heifers presented lower concentrations of GH and IGF-1 than those reported elsewhere in fattening bulls of the same breed. It may be concluded that in Belgian Blue double-muscled females, glucose, IGF-1 and insulin are good indicators of the growth potential. Young adult cows presented intermediate characteristics of metabolic and endocrine status that were close either to younger or to older cows.
| Search for papers on a specific subject | |
|---|---|
 |
|