Sexual Dimorphism in Broilers Following Periods of Equal Water and Feed Intake

Abstract

A study involving three experiments was conducted to investigate patterns of feed and water intake following an initial period in which both sexes received the same water or feed allowance. Restriction of water to an equal intake level in males and females from 0 to 10 days resulted in similar feed intake patterns and similar body weights for both sexes. Following exposure to ad libitum water, males immediately consumed 7 to 11% more water than females, while the accompanying change in feed intake was smaller in magnitude (1 to 6%). Restriction of feed to equal intake levels in both sexes from 0 to 12 days resulted in males and females consuming similar amounts of water. Body weights of males were slightly greater than female weights due to differences in feed efficiency. Following placement under ad libitum feed, males consumed more feed than females (8 to 9%). However, the divergence in feed intake following feed restriction between sexes was more gradual than the divergence in water intake following water restriction. These data indicate that feed and water intake patterns of males and females are controlled by inherent mechanisms independent of differences in body weight or maintenance requirements.

Estimation of the genetic parameters of sexual dimorphism of body weight in 'label' chickens and Muscovy ducks

“…At a given age, they are more mature than males [12,18] Buvanendran [5] in a meat-type chicken line and 0.69 at 40 weeks by Singh et al [32] in a layer-type chicken line. Using REML in layer-type chicken lines, Hagger [14] and Tixier-Boichard et al [35] [20], Marks [21,22]) and the hormonal regulation of growth [4,29,37] contribute to the existence of sexual dimorphism. The correlation between the ratio of male to female body weight and sexual dimorphism was very high in chickens (0.98) which suggested concomitant evolution of both traits.…”

Effects of an In Ovo Injection of an Anti-Androgen on Embryonic and Posthatching Growth of Broiler Chicks

“…Munro and Kosin (1940), Zawalsky (1962), and Whiting and Pesti (1983) found male chicks to be heavier than females at 1 d of age, but Jull and Quinn (1925), Marks (1985Marks ( , 1986Marks ( , 1987, and Burke (1992) did not. In the latter study, two experiments were conducted with eggs from the same commercial broiler cross.…”

“…In both studies, sex differences in live chick weight were not significant but in one of them the difference in yolk-free chick weight approached (P = 0.07) significance. Marks (1987) compared the early growth of males and females of the same strain cross used by Burke (1992) and found males to be significantly heavier than females at 14 d, in one experiment, at 6 d in another, and not to have reached significance at 14 d in a third. Bielfelt and Shultz (1989) found no sex differences in live weight of day-old poults or in their yolk-free BW.…”