PHENOTYPIC AND GENETIC CORRELATIONS BETWEEN PRODUCTION TRAITS IN 2 WHITE LEGHORN STRAINS AND THEIR RECIPROCAL CROSSES

Genetic and phenotypic correlations between production traits like bod y weight at 20 and 40 weeks of age and at first egg, age at first egg, number of eggs produced up to 40 weeks of age and egg weight were est imated from paternal halfsib correlations in 'Meyer' and 'Forsgate' Wh ite Leghorn strains and their reciprocal crosses. Genetic and phenotyp ic correlations among body weight at different growing stages were pos itive in ail genetic groups. The birds heavier at 20 weeks on phenotyp ic level matured early and laid more number of large-sized eggs in all the genetic groups. The puller weight at.20.weeks was not significant ly correlated with age at sexual maturity and egg production on geneti c level. The correlations with egg weight were significant and positiv e in both the purebreds, both generically and phenotypically. The body weight at maturity and egg weight in all the genetic groups, both gen etically and phenotypically. Its correlation with egg number was negat ive in 'Meyer' and positive in 'Forsgate' strain. The genetic and the phenotypic correlations pf age at maturity were negative with egg prod uction and positive with egg weight. No significant generic antagonism s between egg production and egg weight, and between body weight at 40 weeks and egg production were encountered in any of the generic group s. In general all the correlations in crossbreds closely corresponded with those of their purebred parents.