A Comparison of the Productivity of Suckler Cows of Different Breed Composition

Abstract

Growth rate and carcass value are important determinants of profitability, with carcasses of good conformation (muscularity) commanding the highest prices on the premium export markets (mainland EU). Therefore, the objective in suckling is that the progeny are of high growth potential and produce carcasses of good conformation. Breed is the major factor influencing conformation, with the late-maturing continental breeds superior to the early-maturing British breeds (Hereford and Aberdeen Angus) and vastly superior to the Friesian/Holstein. The continental breeds also have greater growth potential than the other breeds. The type of carcasses required are similar to those produced from the suckler herd in France where over 80% of cows are purebred Charolais, Limousin or Blonde d'Aquitaine. However, experimental data have shown that the heterosis (hybrid vigour) resulting from use of a crossbred as opposed to purebred cows increases the weight of calf weaned per cow bred by 14%, with a further 8% arising from using a third breed of sire on a crossbred cow. Because of the emphasis on conformation, producers are retaining replacements from within the herds with a tendency towards purebreds rather than crossbreds. It is thus important to examine the relative productivity of various crossbred and purebred cows to provide clear guidelines on the most desirable breeding programme for the suckler herd. The project involved 5 cow breed types (0.5, 0.75 and 1.0 Limousin genes, Simmental x (Limousin x Friesian) and purebred Charolais) with a common sire used on all cows. Progeny were taken to slaughter. The usefulness of ultrasonic scanning and visual muscular scoring in predicting carcass conformation, fat and composition was also examined.