Maturity and Its Relationship to Muscle Characteristics of Cattle

Abstract
Biopsies were taken periodically from the biceps femoris muscle of 29 calves to study the effects of breed, sex and diet on muscle development during growth. The biopsy samples were frozen in liquid nitrogen, sectioned and stained for NADH-tetrazolium reductase. Photomicrographs of sections were projected onto a grid at a total magnification of × 500. Muscle fibers were classified as red, white, or intermediate and cross-sectional areas were recorded. Fiber type ratios were not affected by diet, sex or age from 40 kg to slaughter weight (340 to 570 kg). However, at a constant body weight larger framed cattle and steers had smaller muscle fibers and less intramuscular fat cell development than smaller framed cattle and heifers, respectively. Copyright © 1980. American Society of Animal Science . Copyright 1980 by American Society of Animal Science.