3-methylhistidine as an Indicator for Protein Beakdown: An Experimental Model in Male Capra hircu
The role of the amino acid 3-methylhistidine as an indicator of protein breakdown and weight loss is often suggested. Despite existing information for other animal species, little is known about the actual levels of 3-methyhistidine in the serum of less studied domestic species such as the goat. We have evaluated the 3-methyhistidine serum concentrations in young Boer goat bucks subjected to two distinct feeding regimens: winter-grass hay with or without supplementation. Non-supplemented animals had a negative nitrogen balance and experienced weight loss throughout the experiment and significantly higher concentrations of 3-methyhistidine than supplemented animals that had a slight increase in live weight. This amino acid can be considered a valid indicator of protein breakdown and weight decrease in male goats. Serum 3-methylhistidine concentrations in adequately fed male goats were similar throughout the assay (20-40 μmol/l) whereas in weight-losing animals, concentrations of up to 170μmol/l can be expected.