Additive genetic and heterosis effects in crosses among cattle breeds of British, European and Zebu origin.

摘要: Breed and heterosis effects for maternal calf components weaning traits were measured in the progeny of Angus (A), Brahman (B) Charolais (C) sires mated to A, B, C reciprocal AB, AC BC dams. Additive breed component weight -3.0 +/- 3.2, -26.6 3.1 29.6 3.3 kg B C, respectively. Corresponding -1.7 2.4, 7.8 2.3 -6.1 2.6 kilograms. Heterosis on 21.2 3.6 1.4 3.7 16.5 3.4 crosses, while levels 28.9 2.7 3.2 18.7 2.9 The corresponding estimates condition scores tended parallel those weight. Approximate relative production efficiency rates computed different mating groups as (calf divided by cow weight) x rate. These values .34 purebred matings, .36 dams raising F1 calves, .40 cows backcross calves .43 three crossbred calves.