Growth hormone (GH), secreted by the anterior pituitary gland, is crucial in the regulation of ruminant growth and development, milk production, and energy metabolism in ruminants. Controlling GH secretion is, therefore, an essential factor in enhancing productivity. We examined D-aspartate (D-Asp) as a factor that stimulates the secretion of GH in ruminants. We used wethers to evaluate GH secretion in response to D-Asp using an intravenous infusion test and experiments with pituitary tissue sections. The results demonstrated that intravenous infusion of D-Asp for 20 min enhanced blood GH concentrations in a dose-dependent manner. Moreover, D-Asp induced-GH secretion by acting directly on the pituitary gland; however, this effect was marginal. GH secretion in response to D-Asp treatment could, therefore, be mediated by the direct and indirect effects on the pituitary gland. Our study suggests that D-Asp could be a potential GH secretagogue in ruminants.

Read the full article in the Journal of Animal Science.