Two experiments were conducted using four strains of Leghorn pullets, namely Babcock,
DeKalb, H & N, and Shaver. Pullets were grown on conventional or low protein diets
fortified with additional amino acids. At 18 wk of age, 64 pullets from each strain
and diet treatment were transferred to individual laying cages, using eight replicate
groups of four adjacently caged birds. In a second experiment, pullets from the four
strains were selected based on body weight at 18 wk of age (approximately 1,270 vs
1,650 g). Each weight group and strain was again represented by eight replicate groups
of four birds. In Experiment 1, there were no strain or rearing diet effects on egg
production (P > 0.05). Rearing diet had little long-term effect on any adult characteristics.
There were significant (P < 0.01) strain effects on body weight, feed intake, and
egg weight, although these were independent of rearing diet. In Experiment 2, regardless
of bird strain, the pullets with smaller body weight matured more slowly (P < 0.01)
and produced less total egg mass to 70 wk age (P < 0.05). These smaller birds ate
less feed and produced smaller eggs (P < 0.01). There were strain effects, independent
of 18-wk body weight, for egg weight and eggshell quality (P < 0.01). It is concluded
that minor strain differences exist with respect to response to juvenile nutrition,
although such effects are only evident in early lay. All strains of bird remain small,
18-wk body weight is reduced, and these birds subsequently eat less feed and produce
smaller eggs.