Author
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Rosebrough, Robert |
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McMurtry, John |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 8/3/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: There are generally two methods for altering lipogenesis in aves: 1) fastin was designed to study short-term responses accompanying either chronic or acute bouts of fasting-refeeding. In the first experiment, 7-day old Shave broilers were fed diets containing either 120 or 300 g crude protein on either an ad libitum basis or on 7 cycles consisting of 1 day of fasting followed by 2 days of feeding. In the second experiment, 28-day old Shaver broilers were subjected to the above regimen, but only for one cycle. Bird were bled and killed on day 1, 2 & 3 of the final cycle for each of these experiments. Measurements taken at these intervals included in vitro lipogenesis (IVL), growth and feed consumption, hepatic enzyme activities a plasma triiodothyronine (T3), thyroxine (T4) and insulin-like growth factor I (IGF-I). Birds fed the lower level of crude protein ad libitum from 7 to d ate less, were smaller and less efficient in growth. De novo lipogenesis and plasma T3 were greater while IGF-I and T4 were less in birds fed the l protein diet. Birds cycled through repeated bouts of fasting-refeeding exhibited remarkable changes on each day of the cycle. The lowest rate of I was noted following a 1 day fast and the greatest after 2 day of refeeding. This pattern was noted in birds fed diets containing either 120 or 300 g crude protein/kg although the responses were exaggerated in birds fed the lower level of protein. Chickens fed a low-protein diet in conjunction wit a single bout of fasting-refeeding exhibited responses that were similar to chronic bouts of fasting-refeeding. The magnitude of fasting-refeeding responses were magnified by repeated bouts. Feeding a high level of protein moderated some of the effects of a single bout of fasting-refeeding. |
