PRODUCTION EFFICIENCY OF DWARF HYBRID LAYER UNDER SUMMER HEAT

The CBD hybrid dwarf pullers showed less decline in egg production (fr om 83.3 to 50.9%) against purebred PBD (from 87.7 to 34.2%) with the r ise of summer temperature from 25.50 degrees to 43.10 degrees C, proba bly due to little change in feed consumed. The CBD maintained feed con sumption within a narrow range of 66.3 to 71.5 g against PBD Of 69.9 t o 86.7 g/day under summer heat. The food consumption mainly depended o n dietary energy (R(2) = 99.98%) content. The predictability for egg p roduction was high fo, PBD (R(2) = 77.74%) than for CBD (R(2) = 22.54% ). It was significantly influenced by body weight and dietary protein consumption. The egg weight and body weight ratio was close to 1: 21.2 for both the genotypes. However, body weight alone explained 63.95% p henotypic variability for egg weight in CBD, but little dependence was observed for heavier PBD genotype. The production efficiency index (P EI) was superior in crossbred dwarf hybrid due to more egg production but equivalent in egg weight to purebred dwarfs.