Blood metabolite profiles of broodmares and foals

Serum amino acid profiles and other serum characteristics of broodmares and their foals wee studied. Compared with mares, foals had significantly higher concentrations of serum leucine, threonine, aspartic acid, asparagine, glutamic acid, glutamine, proline and tyrosine, glucose, cholesterol, creatinine and phosphorus. Foals had significantly less serum histidine, glycine, cystine, taurine, protein and urea nitrogen. Lysine and/or methionine supplementation of pregnant and lactating broodmare diets were conducted. Changes in serum amino acid profiles caused by dietary amino acid supplemented were then quantified. Changes in concentrations of 19 amino acids as well as of ammonia occurred from the first bleeding period (12 weeks prepartum) to the second bleeding period (seven weeks prepartum) in mares supplemented with methionine. When blood samples were collected at 2 h intervals post feeding, after a preliminary rise, a large decrease in serum amino acid levels occurred over a 19 h pot feeding period.