Long-Term Comparisons of Eight-Week Body Weight for a Randombred Line of Chickens Reared at Two Locations

For 36 generations, 8-wk body weight was measured in Athens-Canadian Randombred males and females reared at the Southern Regional Poultry Genetics Laboratory (SRPGL) and at Virginia Polytechnic Institute and State University. Regressions of this trait on generations ranged from -.7 g for females reared in Virginia to -2.6 g for males reared at the SRPGL. Chickens were consistently heavier at the SRPGL, where a broiler diet was fed, than at Virginia, where the diet was considerably lower in protein and energy. Highly significant (P < or = .01) location by generation interactions reflected fluctuations at one location that were independent of those at the other location. Correlations between body weight at the two locations increased when chicks were vaccinated for Marek's disease.