@conference {40682,
	title = {Effects of genotype and nutrition on sheep carcass fat and eye muscle development between weaning and 14 months of age},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {55},
	year = {1995},
	month = {Jan},
	pages = {104-107},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Although several studies have implicated cortisol in the control of  body composition in sheep, the precise mechanisms are unclear. Cortisol  basal concentration and response to an ACTH challenge was studied in  Coopworth wethers selected for (Fat) or against (Lean) fatness in both the  fed and 48 hour fasted states at two stages (15 and 33 weeks). The aim was  to investigate whether fasting, age or genotype would influence cortisol  secretory parameters.   Mean basal cortisol concentration was higher for fasted than fed lambs (13.6  versus 8.9 ng/ml, p<0.001), but did not differ significantly with genotype or  overall stage of development. Maximal cortisol response to ACTH was  greater for the fat than the lean genotype, at both 15 weeks (86.3 versus 65.3  ng/ml, p<0.01) and 33 weeks (108.2 versus 91.1 ng/ml, p<0.01) of age.   Maximal cortisol response was also significantly greater with fasting and  increasing age, but the effect of fasting on cortisol increase was greater at 15  than 33 weeks of age. Clearance of cortisol was significantly slower after  fasting, but unaffected (p>0.05) by genotype and development.   Basal cortisol concentrations was not associated with differences in body  composition between the fat and lean genotypes. However the larger  maximal response in the fat genotype may indicate that the adrenal gland  plays a role in determining body composition.  },
	issn = {1176-5283},
	author = {Binnie DB and Clarke JN and Clayton JB and Mowat CM and Purchas RW}
}
