The role of water intake on sexual dimorphism for early growth of broilers.

Two experiments were conducted to investigate feed intake and body weight of males restricted to the water intake of ad libitum females immediately after hatch. Ad libitum males were heavier and consumed more feed than ad libitum females, with differences becoming significant after Day 10. Body weight and feed intake of water-restricted males and females were essentially identical, suggesting that when males and females receive the same amount of water, they also consume similar amounts of feed. Ad libitum males tended to have higher feed efficiencies than females, whereas water-restricted males and females had similar feed efficiencies. These data indicate that unless males are able to consume more water than females, there is an absence of development of sexual dimorphism in body weight during early life.