Abstract

The concentrations of cholesterol and triglyceride in blood plasma were compared in two genetically distinct herds of Angus cattle. Any concentration differences between the herds should indicate a realised genetic response to selection for yearling weight. Seventy-four yearling Angus cattle from the Waikite weight selection and control herds were blood sampled after a 24-h fast in July, September and November 1993 (heifers twice, bulls three times; n=178 samples). Plasma cholesterol concentrations averaged 2.73 and 2.91 (s.e.d. 0.08) mmol/l in the two herds, respectively (P<0.05), and triglyceride concentrations averaged 0.296 and 0.316 (s.e.d. 0.015) mmol/l, respectively. There was a 30kg (14%) difference in yearling live weight between the two herds (P.001). Both metabolites showed moderate between-animal repeatabilities, 0.52+0.11 and 0.37+0.16 respectively, and there was a positive phenotypic correlation of 0.40 between cholesterol and triglyceride concentrations within herds. These results show that a 14% higher weight-for-age as a result of selection was associated with a 6% lower plasma cholesterol concentration. This was consistent with our previously observed cholesterol difference in cooked beef from the same herds.

NJ, Petrie, KJ Stafford, DJ Mellor, RA Bruce, and RN Ward

Proceedings of the New Zealand Society of Animal Production, Volume 55, , 58-60, 1995