The Performance of Broiler Chicks During and Following a Severe Feed Restriction at an Early Age

Growth, feed efficiency, and abdominal fat were evaluated in broiler chicks that had been subjected to a severe feed restriction at the age of 1 week. The restriction period lasted 6 to 28 days, during which time the birds received 30 to 45 kcal/day in the different experiments. Feed restriction was followed by a period of refeeding which continued up to the age of 8 to 9 weeks. In the restricted birds, weight gain was lower during the first 2 weeks of refeeding but later exceeded that of the controls. In some cases this growth pattern resulted in an almost complete compensation for the weight gain lost during restriction. An improved feed efficiency in restricted groups was observed during refeeding, due in part to their lower body weight. Plots of cumulative feed efficiency vs. body weight indicate that with body weight over 1500 g, cumulative efficiency was improved over the controls. The extent of improvement at final weights was 2 to 3%, 2 to 4%, 5 to 9%, and 5% in the less severe restriction groups of trials 1, 2, 3, and 4, respectively. Abdominal fat at 8 weeks of age was reduced by the early, energy restriction. The possible practical benefit of an early energy restriction regimen is discussed.