Effects of early feed restriction in broilers. I. Growth performance and carcass composition.

The effect of severe nutrient restriction at an early age was investigated in male and female broilers. At day 5 (females) or day 6 (males) post-hatching, chicks on limited intake were provided only enough feed (starter diet) to meet daily maintenance energy requirements only. Restriction was carried out for either 6 or 12 days, after which refeeding was on an ad libitum basis. Ad libitum fed controls were included. Minimal weight gain was noted during the period of restriction. Two weeks following refeeding, weight gains in the treated chicks exceeded that of controls. Final body weights (8 weeks) of 6-day-restricted chicks was slightly greater than controls, whereas 12-day-restricted chicks were significantly lower. Limiting nutrient intake at an early age resulted in better feed efficiency accompanied by less carcass fat and smaller abdominal fat pads. A similar, though not as dramatic effect was observed in female broilers. Results of early feed restriction on broiler growth patterns suggest that significant improvements in feed efficiency can be attained along with a reduction in total body fat.