Effect of feed restriction on growth and sexual development in the domestic fowl: effect on growth, development of ovary and oviduct, and mortality rate
1990
Ratana Chotesangasa (Kasetsart Univ., Bangkok (Thailand). Faculty of Agriculture. Dept. of Animal Science)
Effect of two feed restriction programs, in which the chickens were fed for 8 hours a day (8h-fed group) and for eighty-five percent of the amount consumed by full-fed chickens (85 percent-fed group), and conventional free feeding program (ad libitum group) on growth, The two feed restriction programs applied from 12w onwards caused a delay in growth. Body weight of the 8h-fed group was lower than that of the ad libitum group at 16w. (1271g VS. 1384g. whereas that of the 85 percent-fed group was lower at both 16w (1293g VS. 1384g and 20w (1479g VS. 1550g. Changing a half each of the 8h-fed and 85 percent-fed groups to full feeding, and a half of the ad libitum group to 85 percent feeding, at 40w, resulted in no different body weight at 72w in any but the 85 percent-fed group. The 85 percent-fed turned full-fed bird was heavier than the remained 85 percent-fed bird (1861g VS. 1689g. The difference of feed conversion rate was observed only at the age interval of 12-16w. They were 12.9, 9.1, and 7.1 for the 8h-fed, 85 percent-fed, and ad libitum chickens, respectively. Development of ovary and oviduct was generally depressed by the 85 percent feeding program, though the difference (P0.05) was observed only at the age of 40w. Average numbers of small and medium follicles of the three different feeding programs were not different. Only the number of large follicle was negatively affected by the 85 percent feeding program. At 40w, the average number of large follicle per ovary observed in the 85 percent -fed group was lower than found in the 8h-fed and ad libitum groups. The number was, however, increased to equolity with those of the other two groups after turning to full feeding.
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