THE PERFORMANCE OF ONE NORMAL AND TWO DWARF MEAT MATERNAL GENOTYPES AND THEIR PROGENY AS AFFECTED BY REARING AND ADULT DIETARY TREATMENTS

Abstract

The performances of one normal and two dwarf meat maternal genotypes were compared in a factorial experiment designed to estimate the combined effects of feeding two juvenile diets (low protein (LP) high energy (HE) versus high protein (HP) low energy (LE)) from 106 to 140 days and four adult dietary treatments (LPHE, HPHE, HPLE and an HPLE excluding canola meal) fed from 141 to 420 days. The performance of the three genotypes differed significantly (P < 0.05) for egg production, egg fertility at 322 days, feed efficiency, live body weights and monetary returns less the cost of chicks and feed. One of the dwarf gentoypes exhibited the highest monetary returns. Juvenile dietary treatments had no significant (P > 0.05) effect on the traits measured except age at sexual maturity and female body weights at 154 d. Several traits were affected by the adult dietary treatments including mortality, incidence of fatty liver syndrome, hen-day egg production, feed efficiency up to 322 and 420 days and live body weights. Mortality due to fatty liver syndrome was significantly (P < 0.01) lower among hens fed the high protein, low energy diet without canola meal compared with hens fed the other three adult diets, all of which included canola meal as a feed ingredient. Key words: Dwarf, meat breeders, hens, broilers, diets, fatty liver syndrome, genotypes