Effects of a high-protein, low-energy diet in finishing lambs: 1. Feed intake, estimated nutrient uptake, and levels of plasma metabolites and metabolic hormones

被引:10
作者
Pittroff, W. [1 ]
Keisler, D. H.
Blackburn, H. D.
机构
[1] Univ Calif Davis, Dept Anim Sci, Davis, CA 95616 USA
[2] Univ Missouri, Dept Anim Sci, Columbia, MO USA
[3] USDA ARS, Ft Collins, CO 80522 USA
关键词
sheep; protein-energy ratio; body composition; catabolism; leptin;
D O I
10.1016/j.livprodsci.2005.11.018
中图分类号
S8 [畜牧、 动物医学、狩猎、蚕、蜂];
学科分类号
0905 ;
摘要
Patterns of tissue mobilisation in ruminants are ill-understood. This hinders nutritional management to mitigate the effects of energy deprivation on protein mass, and nutritional regimens designed to change body composition. An experiment was conducted to comprehensively evaluate the effects of a low-energy high-protein diet in growing lambs. Three diets (CON = concentrate diet ad libitum, STR = straw ad libitum, SFM = straw ad libitum plus 150 g/d fish meal) were fed to growing white-face lambs. Analysis of feed intake and metabolite data provided evidence that greater available N did not have a synergistic effect on intake of low quality forage. Metabolite and hormone profiles of lambs in negative energy balance, supplemented with duodenally available protein, revealed that SFM animals did not respond with an accelerated rate of fat mobilization or maintain protein mass due to available N. This was particularly evident from the leptin profiles, which indicated higher circulating leptin levels for SFM compared to STR animals. Further, the data revealed that in sheep fed below requirements for maintenance, leptin levels did not correspond with acute ME intake, whereas the opposite was true for well-fed animals. Conversely, the response of the GH/IGF-1 axis to high protein-energy ratio (PER) diets was indicative of effects not explained by the difference in energy provided by the two experimental diets. These results contrast with observations from intra-gastric infusion experiments testing similar PERs and previous conventional feeding trials and provide evidence of. (1) specific differences associated with PER in lambs fed via intra-gastric infusion vs. a conventional feeding approach, and (2) lack of usefulness of high PER diets in the post hoc modification of body composition of growing lambs. While positive N balance is known to occur in ruminants in negative energy balance, the determinants of relative proportions of muscle and adipose tissue catabolised under energy deprivation remain unknown. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:262 / 277
页数:16
相关论文
共 36 条
[1]  
[Anonymous], 1985, NUTR REQ SHEEP, VSixth
[2]  
AOAC, 1984, OFF METH AN
[3]  
*ARC, 1984, NUTR REQ RUM LIV S, V1
[4]  
Breier B. H., 1995, Ruminant physiology: digestion, metabolism, growth and reproduction. Proceedings, 8th International Symposium on Ruminant Physiology., P451
[5]  
Chowdhury S.A., 1990, P NUTR SOC, V49, p208A
[6]   Protein energy relationships with particular references to energy undernutrition: A review [J].
Chowdhury, SA ;
Orskov, ER .
SMALL RUMINANT RESEARCH, 1997, 26 (1-2) :1-7
[7]   Plasma leptin determination in ruminants: effect of nutritional status and body fatness on plasma leptin concentration assessed by a specific RIA in sheep [J].
Delavaud, C ;
Bocquier, F ;
Chilliard, Y ;
Keisler, DH ;
Gertler, A ;
Kann, G .
JOURNAL OF ENDOCRINOLOGY, 2000, 165 (02) :519-526
[8]   Development of a specific radioimmunoassay to measure physiological changes of circulating leptin in cattle and sheep [J].
Ehrhardt, RA ;
Slepetis, RM ;
Siegal-Willott, J ;
Van Amburgh, ME ;
Bell, AW ;
Boisclair, YR .
JOURNAL OF ENDOCRINOLOGY, 2000, 166 (03) :519-528
[9]   ESTIMATION OF RATES OF OUTFLOW OF PROTEIN-SUPPLEMENT FROM THE RUMEN BY DETERMINING THE RATE OF EXCRETION OF CHROMIUM-TREATED PROTEIN SUPPLEMENTS IN FECES [J].
ELIMAM, ME ;
ORSKOV, ER .
ANIMAL PRODUCTION, 1984, 39 (AUG) :77-80
[10]   FACTORS AFFECTING THE OUTFLOW OF PROTEIN SUPPLEMENTS FROM THE RUMEN .2. THE COMPOSITION AND PARTICLE-SIZE OF THE BASAL DIET [J].
ELIMAM, ME ;
ORSKOV, ER .
ANIMAL PRODUCTION, 1984, 39 (OCT) :201-206