Effect of feed restriction on growth and sexual development in the domestic fowl: Effect on steroid hormone levels, egg production and egg composition
1990
Ratana Chotesangasa (Kasetsart Univ., Bangkok (Thailand). Faculty of Agriculture. Dept. OF Animal Science)
Two feed restriction programs; in which the 12-week-old chickens had access to feed for 8h a day (8h-fed group), and each day for 85 percent of the calculated amount of feed consumed by the conventional full fed (85 percent-fed group). were compared with the free feeding program in which the chicken received the some diet but on an ad libitum basis (ad libitum group). Serum progesterone and estradiol levels of the three groups were generally increased with age from growing to laying period. The feed restriction did not affect the age. body weight, and egg weight at the onset of lay, it resulted in a delay on age, a heavier body weight and a larger egg size at the 50 percent egg production. The effect on hen-day egg production was obvious. From the onset of lay to 40 weeks of age, the ad libitum, 8h-fed, and 85 percent-fed chickens laid the mean number of 89.7, 61.0, and 49.9 eggs/bird, respectively The depressing effect on egg production was lifted once the restricted birds were turned to the full feeding. The mean number of eggs produced during the age of 40-72w of the 8h-fed turned full-fed, and 85 percent-fed turned full-fed groups were 143.9 and 155.2 eggs/bird, respectively compared with the 128.0 eggs/bird of the ad libitum group (P0.05). Furthermore, the 85 percent-fed turned full-fed group was able to maintain at the peak production rate of about 19-20 eggs/bird/4w for a longer duration than the ad libitum group. Neither the 8h a day feeding nor daily 85 percent feeding showed an effect on the egg weight and egg composition of the experimental chicken.
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