Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 3, 1997
Publication Date: N/A
We have repeatedly shown that low-protein diets increase lipogenesis and decrease feed intake. Even though low protein diets are high in carbohydrates, carbohydrates are secondary to protein level during suboptim protein nutrition. Metabolic responses are under the control of protein under these conditions. The purpose of this experiment was to study dietar rprotein's role in metabolic adaptations in birds given T3 at 28 d of age. Male, Indian River broilers were fed diets containing either 120 or 300 g crude protein/kg from 7 to 28 d. One-half of each group was given that die supplemented with 1 mg/ kg T3. Birds were sampled at 0, 2, 5, 7, 9 and 12 following the switch. Measurements taken included in vitro lipogenesis (IVL), growth and feed consumption, hepatic enzyme activities and plasma thyroid hormones and metabolites. Pancreatic norepinephrine was measured t determine if the central nervous system regulated metabolic changes. As expected, IVL was greater at 28 d in birds fed the lower level of protein. When T3 was added to either diet, IVL decreased by 50% after 5 d. Plasma I level of crude protein. Plasma T3 increased and T4 decreased 3 d following the addition of T3 to diets containing either level of crude protein. Pancreatic amylase was greater and norepinephrine less in birds fed the higher level of crude protein, lending some support for neural control of pancreatic activities. Most metabolic changes in response to feeding T3 occurred within 2 to 5 d, suggesting that changes in intermediary metabolis preceded morphological changes.