Effect of fish-meal supplementation and β-agonist administration on adipose tissue metabolism in steers given silage

Dawson, J. M.; Essex, C. P.; Walsh, Ann; Beever, D. E.; Gill, M.; Buttery, P. J.

doi:10.1017/s1357729800042727

Cited by 2 publications

(2 citation statements)

References 28 publications

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“…The software was used to measure the diameters of 50 individual intact adipocytes, and, as adipocytes were assumed to be spherical, the diameter was used to determine the volume of the cells. The number of adipocytes per gram of adipose tissue was calculated from the mean adipocyte volume, total lipid per gram, and an assumed lipid density of 0.915 g/mL (Taylor et al, 1973;Dawson et al, 1993).…”

Section: Determination Of Adipocyte Volume and Adipocyte Numbermentioning

confidence: 99%

Differing effects of forage and concentrate diets on the oleic acid and conjugated linoleic acid content of sheep tissues: The role of stearoyl-CoA desaturase1,2

Daniel

Wynn

Salter

et al. 2004

Journal of Animal Science

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124

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Feeding sheep concentrate-based diets increases the oleic acid content of their tissues, whereas the cis-9, trans-11 conjugated linoleic acid (CLA) content is increased by feeding forage diets. Both these metabolic transformations could be attributable to increased activity of stearoyl-CoA desaturase (SCD). Therefore, the effect of forage or concentrate feeding regimens on the fatty acid composition of sheep tissues were investigated to determine whether any changes are related to an alteration of SCD mRNA levels. Twenty-four ewe lambs were randomly allotted to one of three dietary treatment groups: 1) dehydrated grass pellets, 2) concentrate diet fed to achieve a growth rate similar to that of the dehydrated grass pellets, and 3) the same concentrate diet approaching ad libitum intake. As expected, animals fed ad libitum concentrates grew at a greater (P = 0.001) rate (280 g/d) than those fed either of the other two diets (180 g/d), which were similar. In samples of liver and the three adipose tissue depots studied, the concentration of oleic acid from sheep fed either level of the concentrate diet was greater (P < 0.001) than from animals fed forage. This was associated with an increase (P < 0.05) in the ratio of SCD to acetyl-CoA carboxylase mRNA in adipose tissue and liver. Compared with concentrate-fed, the forage-fed lambs had increased (P < 0.05) levels of the cis-9, trans-11 isomer of CLA and C18:1, trans-11 in all their tissues, although the levels of SCD mRNA were lower. It therefore seems that the increased oleic acid content of sheep tissues in response to concentrate-rich diets is associated with an increase in SCD gene expression. By contrast, the increased concentration of CLA in animals fed forage-based diets is associated with an increase in substrate (C18:1 trans-11) availability.

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Section: Determination Of Adipocyte Volume and Adipocyte Numbermentioning

confidence: 99%

Differing effects of forage and concentrate diets on the oleic acid and conjugated linoleic acid content of sheep tissues: The role of stearoyl-CoA desaturase1,2

Daniel

Wynn

Salter

et al. 2004

Journal of Animal Science

Self Cite

124

View full text Add to dashboard Cite

show abstract

“…Plasma IGF-1 concentrations were determined in the same samples by radioimmunoassay after acid-ethanol extraction (Pel1 & Bates, 1992). Plasma insulin concentrations were measured by radioimmunoassay kit (Medgenix Ltd, High Wycombe, Bucks., UK) while glucose and urea-N concentrations were determined colorimetrically as described previously (Dawson et al 1993~). As heparin interferes with the determination of non-esterified fatty acid (NEFA) concentrations, these measurements were made on plasma samples taken during the palmitate infusions using the Wako Feed intake ( x maintenance) Fig.…”

Section: Measurement Of Plasma [13c]leucine Enrichment L-mentioning

confidence: 99%

The interaction between nutritional status and growth hormone in young cattle: differential responsiveness of fat and protein metabolism

et al. 1998

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The effect of dietary intake level on in vivo plasma leucine and plasma palmitate flux rates and on the response to a bolus injection of bovine growth hormone (GH) was investigated in six young steers. Animals were fed on a pelleted diet of dried grass-barley (0.7 : 0.3, w/w) in quantities sufficient to supply 0.8, 1.2, 1.6, 2.0, 2.4 or 2.65 x maintenance energy requirement, offered in hourly portions. Continuous intravenous infusions of [ l-'3C]leucine or [ l-'3C]palmitate were used to determine the flux of amino acid and fatty acid through the plasma pool before, immediately (1-3 h) after and 22-24 h after a subcutaneous injection of bovine GH (0.55 mg/kg body weight). Hourly blood samples were taken for 27 h to monitor the temporal responses of circulating hormones and metabolites following GH administration. The animal on the lowest plane of nutrition had elevated plasma GH and reduced insulin-like growth factor-1 concentrations compared with those fed on higher intake levels. Plasma leucine flux and leucine concentration increased with intake while palmitate flux and plasma non-esterified fatty acid (NEFA) concentrations were inversely related to intake. Leucine flux rate decreased in the animals fed on the two highest intake levels in response to GH 22-24 h after administration, but plasma leucine concentrations were reduced in all animals at this time. Only the animal fed on the lowest intake level showed an immediate response to GH (within 3 h of administration) with increased palmitate flux and plasma NEFA concentrations but a lipolytic response was apparent in other animals 22-24 h post-administration although the magnitude of the response was markedly reduced at high intakes. We conclude that lipid and protein metabolism are differentially responsive to GH and nutritional status.Growth hormone: Palmitate: Leucine: CattleThe partitioning of nutrients between lean and fat deposition is an area of great current interest in farm livestock production. Nutritional status has a marked influence on nutrient utilization and body composition which is at least partly modulated through changes in the endocrine status of the animal. The role of growth hormone (GH) in the control of animal growth is well documented. It has somatogenic or metabolic effects on a multitude of tissues and is a homeorhetic regulator of the postabsorptive use of nutrients. Its use in animal production has focused on its influence in effecting changes in the partitioning of nutrients between muscle and fat in response to exogenous administration resulting in improved lean : fat ratios. The anabolic effects of GH on muscle are believed to be largely mediated by insulin-like growth factor-1 (IGF-1) which stimulates protein synthesis (Douglas et al. 1991) while the effects of GH on adipose tissue are thought to be mediated directly by binding to GH receptors on the adipocyte membrane. The magnitude of the response to exogenous GH administration is variable and at least partly attributable to nutritional status. An interaction between nutriti...

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Effect of fish-meal supplementation and β-agonist administration on adipose tissue metabolism in steers given silage

Cited by 2 publications

References 28 publications

Differing effects of forage and concentrate diets on the oleic acid and conjugated linoleic acid content of sheep tissues: The role of stearoyl-CoA desaturase1,2

Differing effects of forage and concentrate diets on the oleic acid and conjugated linoleic acid content of sheep tissues: The role of stearoyl-CoA desaturase1,2

The interaction between nutritional status and growth hormone in young cattle: differential responsiveness of fat and protein metabolism

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