Characterization of insulin and growth hormone receptors in bovine tissues

Binding of (\u27125)I bovine insulin and (\u27125)I bovine growth hormone (bGH) to mononuclear cells isolated from blood and plasma membranes isolated from liver, kidney and fat was characterized in both rats and cattle. In both rats and cattle, insulin and GH receptors exhibited specificity and high affinity (Ka(,1) 5 to 10 x 10(\u278) M(\u27-1) and Ka(,2) 2 to 20 x 10(\u277) M(\u27-1)). Bovine mononuclear cells had approximately 3,700 high affinity and 15,000 low affinity sites for insulin per cell. All bovine tissue membranes examined exhibited similar insulin binding characteristics, but maximum binding percentage was 1/3 that of rat tissues. Membranes isolated from rat liver and adipose tissue bound similar amounts of insulin, while membranes from kidney bound only 1/10 of that by liver and adipose. GH did not bind specifically to cattle mononuclear cells. GH binding to liver membranes of rats and cattle was similar. Rat kidney membranes specifically bound GH, but specific binding of bGH could not be demonstrated in bovine kidney. This study indicates bovine insulin and GH receptors are physically similar to those in rats, but major organ differences exist, especially in the kidney. Binding of insulin and bGH was also characterized in tissues from large and small framed cattle to determine if modulation of receptors plays a role in regulating hormone action. Mononuclear cells isolated from small framed cattle had lower binding capacity than did cells isolated from large framed cattle, but this difference was small compared with the higher concentrations of plasma insulin observed in the small cattle. These differences in insulin receptors on mononuclear cells were not associated with parallel changes in liver and kidney membrane receptors. There was no difference in amount of bGH bound to liver membranes of large and small framed cattle. These studies suggest insulin and bGH receptors play a relatively minor role in modifying hormone action in cattle growth and metabolism

Method of raising meat producing animals to increase lean tissue development

A method is provided for raising meat producing domestic animals to increase lean tissue development. β-hydroxcy-β-methylbutyric acid or an edible salt thereof (HMB) is administered to the animals in an effective amount for a sufficient length of time to obtain a substantial increase in lean tissue weight. Feed compositions for use in practicing the method are also provided. The method and feed compositions are particularly adapted for use with ruminants, including beef cattle and lambs, since HMB is not subject to appreciable rumen destruction. The method can also be practiced with other domestic animals, including chickens, and turkeys

Method of enhancing immune response of mammals

β-methyl-βbutyrate (HMB) has been found to be markedly more effective for activating the immune function of T lymphocytes of mammals than α-ketoisocaproate (KIC). For activation of the T lymphocytes, β-methyl-butyric acid or an edible water-soluble salt thereof is administered to the mammal by a route through which the HMB enters the blood of the mammal. The amount administered is sufficient for effective enhancement of the blastogenesis of their T lymphocytes. The method is adapted for use with domestic mammals, including particularly cattle, sheep, and swine. HMB can also be used with humans as an immune system stimulant.</p

Method of feeding ketoisocaproate to lactating domestic mammals

Lactating domestic mammals are fed ketoisocaproate (KIC) with a diet containing limited leucine to improve the quantity and quality of the milk produced. This feeding method is particularly applicable to dairy cattle but also can advantageously be used with nursing domestic animals including cattle, sheep, goats, horses, and swine

Feed compositions for domestics animals containing hydroxymethylbutyrate

Feed compositions are provided for raising meat-producing ruminants and polutry. β-hydroxcy-β-methylbutyric acid or an edible salt thereof (HMB) is incorporated in the ruminant or poultry feeds to obtain a substantial increase in meat and/or to improve the quality of the lean meat

Method of feeding ketoisocaproate to cattle and sheep

Cattle and sheep are fed ketoisocaproate (KIC) with a diet of limited leucine content for enhancement of growth and feed efficiency. The method is especially applicable to beef cattle and sheep being raised for meat production, but it can also be used with veal calves and mature sheep being fed for wool production

Rumensin: A New Feed Additive for Feedlot Cattle

Because feed comprises over 80% of the cost of producing fat cattle, considerable research has been directed towards improving utilization of the energy in feeds by ruminants. Attempts to get more energy from cattle feeds have included grinding, pelleting, steam flaking, feeding ensiled high moisture grains and feeding high concentrate rations

Method for measuring muscle mass

A method for determining muscle mass in a human subject useful for monitoring athletic conditioning, weight loss programs, nutritional deficiencies, and disease states which cause muscle wasting is provided comprising administration of a bolus dose of a metabolic marker for 3-methylhistidine, the use of a three-compartment model to describe data from blood samples collected periodically thereafter, and calculation of muscle mass as a function of specific values generated by the model