Early and temporary quantitative food restriction of broiler chickens. 2. Effects on allometric growth and growth hormone secretion

1. An experiment was conducted with male broiler chickens to investigate th e effect of different early food restriction programmes on proportional wei ghts and allometric growth coefficients of carcase parts and on pulsatile g rowth hormone secretion. 2. At 4 d of age the animals were restricted to 80% or 90% of the ad libitu m intake for 4 d or 80% for 8 d. When the restriction was finished, all bir ds received ad libitum food again. 3. On d 1, 8, 11, 14, 21, 28, 35 and 42, from each group 8 birds were weigh ted, stunned and killed and the weights of the stomachs, liver, heart, ster num, right thigh, right drumstick, breast and abdominal fat pad were determ ined. On d 29, 30, 31, 32 serial blood samples of 2 birds from each group w ere taken to determine the plasma growth hormone (GH) content. 4. Only the most severe restriction resulted in a tendency for the stomachs to mature earlier and the thighs to mature Inter. No other significant eff ect on the allometric coefficients could by observed. 5. It is concluded that during the restriction the birds give priority to t he development of the supply organs such as Che stomach, which are more imp ortant during early development, at the expense of the demand tissues like breast and thigh. 6. No significant differences concerning the GH secretory parameters could he observed.