Nutritional and hormonal control of muscle and peripheral tissue metabolism in farm species

Lobley, G. E.

doi:10.1016/s0301-6226(98)00186-9

Cited by 58 publications

(46 citation statements)

References 85 publications

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“…In contrast, GH stimulates triglyceride breakdown and then enhances the conversion of fatty acids to acetyl CoA and subsequent utilisation of these substrates for energy (Breier, 1999). GH also increases the accretion of protein by increasing the transfer rate of amino acids into cells to be used for protein synthesis and by decreasing the catabolism of proteins (Oddy, 1993;Lobley, 1998).…”

Section: Discussionmentioning

confidence: 99%

The effect of ingesting a saltbush and barley ration on the carcass and eating quality of sheepmeat

Pearce

Pethick

Masters

2008

Animal

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Forage halophytes such as saltbush (Atriplex spp.) are widely used to revegetate Australian saline land and can provide a medium-quality fodder source. An animal house experiment was conducted to investigate differences in the carcass and eating quality of sheep ingesting saltbush from saline land in combination with a barley supplement. Twenty-six merino hoggets (two groups of 13) were fed either a 60 : 40 dried saltbush (Atriplex nummularia): barley (S 1 B) ration or a 33 : 25 : 42 lupins : barley : oaten hay ration (C) for 10 weeks prior to commercial slaughter. After 10 weeks, all sheep were commercially slaughtered and a single loin (from 12th rib to chump) collected from each animal for taste-panel analysis. Carcass weight, total tissue depth over the 12th rib 110 mm from the midline (GR fat depth), ultimate pH and colour were determined and X-ray bone densitometry used to estimate the fat content of the carcass. Blood samples were taken to assess the hormonal response to ingesting these diets and fatty acid profiles of the subcutaneous and intramuscular fat were determined. Both groups grew at the same rate (62 g/day) and had similar hot carcass weights (P . 0.01) (17.2 6 0.3 kg for S 1 B and 17.9 6 0.3 kg for C). However, these live weights may not be high enough to be commercially viable such that saltbush and barley may only be suitable as a maintenance feed. The S 1 B-fed sheep had a significantly (P 5 0.055) lower fat and higher lean content (P , 0.05) than the C group. This is a positive finding as fat denudation is a significant cost to processors and farmers can produce sheep that are depositing less fat or more lean per unit of live-weight gain. The decreased fat and increased lean content were attributed to the higher protein : energy ratio available for production and lower circulating insulin and higher growth hormone of the S 1 B-fed sheep. The lower body-fat content and lower metabolisable energy and digestible organic matter intake did correlate with the sheep fed the S 1 B diet, having a significantly lower percentage of unsaturated fat and equal levels of saturated fat than the C treatment. Diet had no effect on the ultimate pH or colour of the meat. Treatment had no significant effect on any of the eating-quality attributes (P . 0.1). The drying of the saltbush, the shorter length of the experimental period and the low carcass fat content were believed to have contributed to this result. Further field experiments are needed to clarify the benefits to carcass and eating quality of ingesting saltbush.

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Section: Discussionmentioning

confidence: 99%

The effect of ingesting a saltbush and barley ration on the carcass and eating quality of sheepmeat

Pearce

Pethick

Masters

2008

Animal

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“…The relative proportion of each tissue to overall protein metabolism could vary with the level of intake, due to differences in AA disposal to the tissues and/or the sensitivity of the tissues to the anabolic or catabolic hormones. Muscle has been postulated to exhibit a curvilinear response to intake [16] and this would then account, in part, for the pattern of whole body protein flux. More detailed companion analysis [19] of muscle responses in the current animals did not show any curvilinear effect over the intake range for either protein synthesis or breakdown.…”

Section: Discussionmentioning

confidence: 99%

“…From various data, based on the kinetics of a limited number of amino acids (especially phenylalanine and leucine), it has been proposed [7,16] that ruminant peripheral tissue protein metabolism responds in a curvilinear manner as intake is increased between fasting and supra-maintenance levels. This was then postulated to relate to muscle tissue responsiveness to the anabolic polypeptide hormones, insulin and insulin-like-growth factor-1, with differential responses in protein synthesis and degradation when intake is altered.…”

Section: Introductionmentioning

confidence: 99%

“…This was then postulated to relate to muscle tissue responsiveness to the anabolic polypeptide hormones, insulin and insulin-like-growth factor-1, with differential responses in protein synthesis and degradation when intake is altered. Unfortunately, the individual experiments available from the literature for such an analysis only provide a limited number of intakes [16]. Furthermore, whether the same pattern of response occurs for other tissues (and thus whole body protein metabolism) has not been examined.…”

Section: Introductionmentioning

confidence: 99%

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Effect of intake on whole body plasma amino acid kinetics in sheep

Savary-Auzeloux¹,

Hoskin

Lobley³

2003

Reprod. Nutr. Dev.

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-While both the quantity and quality of food ingested are potent regulators of whole body protein metabolism in ruminants, little data are available on responses across a wide range of intakes. The current study examined the responses in whole body protein flux (PrF) to such intake changes and compared these with the responses across the hind-quarters (in a companion study). Six growing sheep (6-8 months, 30-35 kg) received each of four intakes of dried grass pellets (0.5, 1.0, 1.5 and 2.5 times maintenance energy; M) for a minimum of 7 days. At each intake, a mixture of U-13 C amino-acids (AA) was infused intravenously for 10 h. Arterial plasma and blood were obtained over the last 4 h of infusion and the concentrations and the enrichments of thirteen 13 C labelled AA were determined. The absolute values for plasma Irreversible Loss Rate (ILR) but also converted PrF varied between the AA. PrF values were lower for histidine, methionine, aspartate, glycine and proline (range 68 to 174 g·d -1 at 1.5 M) than for isoleucine, leucine, valine and glutamate (range 275 to 400 g·d -1 at 1.5 M). These discrepancies may be explained by (1) the differential AA removal by the splanchnic tissues, (2) the de novo synthesis of the non-essential AA, (3) the transfer of AA from the erythrocytes or plasma to the tissues. The first two assumptions require further investigation whereas recent work has shown a minor role for AA transfers between erythrocytes and tissues. For most AA, ILR and PrF responded linearly to intake but curvilinear responses were observed for phenylalanine, lysine, leucine, isoleucine and tyrosine. These differences were not due to hind-quarter metabolism and may involve the digestive tract and liver.intake / whole body / kinetics / ovine / amino acid Reprod. Nutr. Dev. 43 (2003) 117-129 117

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“…Amino acids have also a major effect in controlling metabolism (see Grizard et al, 1995 and1999;Lobley, 1998;Muramatsu, 1990;Nieto and Lobley, 1999;Prod'homme et al, 2004 for reviews). They are first substrates for protein synthesis and the lack of even a single essential amino acid causes a decrease in protein synthesis.…”

Section: Effect Of the Nature Of Nutrientsmentioning

confidence: 99%

Responses to nutrients in farm animals: implications for production and quality

Hocquette

Tesseraud

Cassar-Malek

et al. 2007

Animal

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It is well known that any quantitative (energy and protein levels) and qualitative (nature of the diet, nutrient dynamic) changes in the feeding of animals affect metabolism. Energy expenditure and feed efficiency at the whole-body level, nutrient partitioning between and within tissues and organs and, ultimately, tissue and organ characteristics are the major regulated traits with consequences on the quality of the meat and milk produced. Recent progress in biology has brought to light important biological mechanisms which explain these observations: for instance, regulation by the nutrients of gene expression or of key metabolic enzyme activity, interaction and sometimes cross-regulation or competition between nutrients to provide free energy (ATP) to living cells, indirect action of nutrients through a complex hormonal action, and, particularly in herbivores, interactions between trans-fatty acids produced in the rumen and tissue metabolism. One of the main targets of this nutritional regulation is a modification of tissue insulin sensitivity and hence of insulin action. In addition, the nutritional control of mitochondrial activity (and hence of nutrient catabolism) is another major mechanism by which nutrients may affect body composition and tissue characteristics. These regulations are of great importance in the most metabolically active tissues (the digestive tract and the liver) and may have undesirable (i.e. diabetes and obesity in humans) or desirable consequences (such as the production of fatty liver by ducks and geese, and the production of fatty and hence tasty meat or milk with an adapted fatty acid profile).

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Nutritional and hormonal control of muscle and peripheral tissue metabolism in farm species

Cited by 58 publications

References 85 publications

The effect of ingesting a saltbush and barley ration on the carcass and eating quality of sheepmeat

The effect of ingesting a saltbush and barley ration on the carcass and eating quality of sheepmeat

Effect of intake on whole body plasma amino acid kinetics in sheep

Responses to nutrients in farm animals: implications for production and quality

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