Force-feeding effects on growth, carcass and blood composition in the young chick

Abstract

1. Excessive amounts of food (70% greater than ad lib . intake) introduced into the gastrointestinal tract of young chicks were efficiently digested and caused increased growth resulting mainly from lean body substance and partially from fat deposition, more efficient energy utilization than the ad lib .-fed controls, increased relative weights of the crop, proventriculus, intestine, liver and abdominal adipose tissue. Pancreas relative weight was not changed and that of the gizzard was reduced. 2. The treatment also caused changes in blood plasma composition. Free fatty acid, trigly-ceride, α 2 -, β- and γ-globulin and pre-β-lipoprotein concentrations increased. 3. Fasting for 30 h caused higher body fat losses and lower body protein losses in the force-fed chicks than in the ad lib .-fed chicks. 4. The effects of over-feeding on body and blood plasma composition and differences found in these measurements during starvation are discussed.