Environmental and genetic causes of variation in production traits of Damascus goats. 2. Goat productivity

Data on 1474 lactation records obtained from 1972 to 1978 were used to study environmental and genetic influences on production characters in the Damascus goat. Year and month of kidding had a significant effect on 90- and 150-day milk production after weaning, lactation length and litter weight at weaning ( P Estimates of heritability, from paternal half-sib correlations, for 90- and 150-day milk production were similar (0·29 (s.e. 0·14)). The genetic correlation between 90- and 150-day milk yield (0·92 (s.e. 0·03)) was high, indicating that part and whole lactation yields are influenced by the same genes. The phenotypic correlations among milk yield traits and lactation length were also high and positive.