![]() |
|
|
Roman L. Hruska U.S. Meat Animal Research Center, U.S. Department of Agriculture, Agricultural Research Service, P.O. Box 166, Clay Center, NE 68933
Male (61) and female (53) Sprague-Dawley rats (31 d of age, 85 g) were used to evaluate the influence of plane of nutrition on body composition, internal organ size and energy utilization. Six male and nine female rats were sacrificed initially. The remaining animals were randomly assigned, within sex, and fed to gain either 105 g (H) or 40 g (M) or lose 25 g (L) during a 21-d period. Nine rats each from the H and M groups and six from the L group were then sacrificed. The remaining rats from the H (27) and M (27) groups were fed to gain at the H, M or L rate and rats from the L (12) group were fed to gain at the H or M level during a second 21-d period. All rats were sacrificed at the end of the second period. Body composition and weights of internal organs were determined and relationships between energy intake and energy gain were evaluated. Results indicated that at the end of period 2, body composition at equal age and body weight was influenced by nutritional treatment. At equal body weight, body protein weights were lower (P < 0.05) and body fat, liver and gut weights higher (P < 0.05) for rats on higher planes of nutrition. Feed required for maintenance of rats during period 2 tended to be lower and efficiencies of gain tended to be higher for rats fed the low level than for those fed the high level during period 1. Rats fed the medium level during period 1 had similar maintenance requirements but higher efficiencies of gain during period 2 than rats fed the high level during period 1. These results suggest that previous nutrition influenced energy utilization through adaptation of high energy expending internal organs as well as through alterations in body composition and composition of body weight gain.
KEY WORDS: rats nutrition level energy utilization body composition body organs
1 Present address: Agriculture Experiment Station, College of Agriculture, University of Nevada-Reno, Reno, NV 89557.
Manuscript received 11 June 1986. Revision accepted 25 June 1986.
This article has been cited by other articles:
![]() |
B. J. Renquist, T. E. Adams, B. M. Adams, and C. C. Calvert Dietary restriction reduces the rate of estradiol clearance in sheep (Ovis aries) J Anim Sci, May 1, 2008; 86(5): 1124 - 1131. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. G. Jenkins and C. L. Ferrell Daily dry matter intake to sustain body weight of mature, nonlactating, nonpregnant cows J Anim Sci, July 1, 2007; 85(7): 1787 - 1792. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. J. Ramsey and K. Hagopian Energy Expenditure and Restriction of Energy Intake: Could Energy Restriction Alter Energy Expenditure in Companion Animals? J. Nutr., July 1, 2006; 136(7): 1958S - 1966S. [Abstract] [Full Text] [PDF] |
||||