The Effect of Cow Size, Milk Yield and Cow Fatness on the Carcass Characteristics and Meat Quality of Their Progeny

Abstract

Cattle were produced from a foundation herd having a wide range in mature size and milk yield. All heifers were bred to Angus sires to minimize calving problems. All cows were bred to a Simmental sire for second and third calves. Calves (heifers and steers) were weaned at about 6 mo of age and fed a diet largely based on corn silage. Cattle by Angus sires were slaughtered at 10mm backfat thickness evaluated ultrasonically and those by Simmental sires at 7mm. One side of each carcass was separated into fat, lean and bone. The m. longissimus dorsi from the 9–10–11th rib region was removed, vacuum packaged and stored at —29°C for later quality determinations. A 100kg increase in cow weight alone gave calves that were 28kg heavier at slaughter, 14kg more lean tissue, 1.8kg more fat and 3.4kg more carcass bone. Dam's milk yield had no significant effect on carcass tissue yield. A 1mm increase in fatness of dam at calving decreased progeny carcass lean yield by 2.6kg, fat by 0.4kg and bone by 0.8kg. All the cow factors measured (cow size, milk yield, cow fatness) had no significant effect on taste panel scores for flavour, juiciness, tenderness or overall acceptability. There were also no differences between steers and heifers for taste panel scores. It was concluded that cow factors have little overall effect on the final meat quality of their calves when comparisons are made at similar carcass fatness.