EVALUATION OF 3-BREED COMPOSITES ALONGSIDE ANGUS CONTROLS FOR GROWTH,REPRODUCTION, MATERNAL, AND CARCASS TRAITS

Angus cows at two locations were used to generate purebred controls an d three three-breed crosses, as a result of inter-mating two-breed (ha lfbred Angus) crosses. The three-breed crosses were: 25% Simmental, 25 % Friesian, 50% Angus (SiFA) from reciprocal matings between SiA and F A crosses; 25% Maine Anjou, 25% Jersey, 50% Angus (MaJA) from reciproc al matings between MaA and JA crosses; and 25% Blonde d'Aquitaine, 25% Jersey, 50% Angus (BaJA) both from matings between JA bulls and BaA c ows, and from matings between BaJ bulls and A cows. Breed crosses for this experiment were selected as potentially contributing to productiv e crossbred cows, based on the early years of two-breed cross data. Af ter producing the first generation (F1) of three-breed crosses, each c ross was subsequently interbred to produce F2 and F3 calves (202 sire groups overall). There were overlapping generations and contemporary c ontrols, to compare crosses for growth, reproduction, maternal and car cass traits. The three three-breed crosses had greater yearling weight s as F1s than contemporary A animals, by an average of 7.5%. Calf surv ival of the breed-types and generations was similar to A, except for S iFA F1 calves which experienced more difficulty and 17% greater birth weights than A calves. Three-breed cross cows were, on average, 7% hea vier than A cows as F1s and their calves were 11% heavier at weaning t han A calves. On average, the F1 cows showed a 12% advantage over A in calves weaned per cow joined, 24% in productivity, and 16% in product ivity adjusted for cow weight (efficiency ratio). For carcass data (Ba JA and A only), the BaJA calves were heavier and leaner than A control s. The breed types varied in their advantages in efficiency ratio, rel ative to A, and this appeared to depend on the pathway and dam genotyp e used to breed them. The efficiency ratio of contemporary two-breed c rosses was similar to that of the three-breed crosses on average. The best breed types were two-breed crosses, so the three-breed crosses we re likely to be less favoured by the farmer.