SEXUAL DIMORPHISM IN THE GROWTH PATTERN OF BRIOLERS UNDER DIFFERENT DIETARY AND HOUSING CONDITION

Résumé

Two hundred and seventy day old broiler chicks were randomly distributed among three dietary treatment (iso-nitrogenous high and low energy straight-run diets and a conventional broiler diet) and two housing condition (the cage and deep litter) to study the comparative growth pattern between the male and female broilers. Each treatment was replicated thrice at 15 birds per replicate. The chicks were raised for 8 weeks. There were significant interactions (p<0.05) between age, diet housing location and sex. The male broiler had significantly (p<0.05) higher body weight gains than the females especially at the finisher phase. While the females performed better on high energy diet at both phases, the males respond to low energy diet at the starter phase and high energy at the finisher, hence a narrow male: female divergence ratio at the finisher phase. Generally, location had no significant effect (p>0.05) on body weight gains (215.0g vs 214.3g/bird/wk – cage vs floor). However, males gained slightly more weight in the cage while female gained slightly more on deep litter. Both recorded higher gains on the floor at the starter phase and in the cage at the finisher period. Coefficient of variation was respectively lower for the male broilers, birds in the cage, birds at the finisher phase and lowest for birds on conventional diet. Feed consumption was significantly higher (p<0.05) for lower energy diet (68.9 vs 65.1g/birds/day) as well as by birds in the cage (69.4 vs 64.5g/birds/day) with correspondingly lower utilization rate.