Abstract

To determine the incidence of high ultimate pH (pHu) across farms 967 cattle were involved in a survey which showed 3% of Angus, 21% of Simmental cross and 60% of the Friesians steers had an pHu above the acceptable maximum of 5.8. In further work, muscle (longissimus dorsi) biopsies samples were taken from 60 two-year-old Angus, Simmental cross and Friesian steers (n = 20 per breed) in late November and assayed for glycogen concentration and enzyme concentrations that indicated muscle fibre type. Behaviour measurements were made on all animals before slaughter. Individual measurements of carcass characteristics were made 22-24 hours after slaughter, including carcass weight, pHu, meat colour score, and fat depth (GR). Only one carcass had a pHu above 5.8 and there was no pHu difference between breeds (5.53, 5.55, and 5.58 for Angus, Simmental cross, and Friesian, respectively). There was no difference between breeds in the glycogen concentration in the muscle, although there were differences in enzyme concentrations that suggested differences between breeds in the proportion of the three muscle fibre types. Flight distance were small (4-7 m) but longer for Friesian than Simmental cross steers. There were no relationships between meat pHu and flight distance, glycogen concentration or muscle enzyme concentrations. Breed did not appear to effect pHu or muscle glycogen concentration.

RW, Webby, AD Fisher, MG Lambert, and P Turner

Proceedings of the New Zealand Society of Animal Production, Volume 59, , 287-290, 1999