Splanchnic extraction of phenylalanine in mature mares was not affected by threonine supplementation.

This research aimed to determine if the splanchnic extraction of phenylalanine in horses is affected by the intake of threonine. The study found that phenylalanine kinetics did not change significantly with different dietary supplements, suggesting threonine supplementation does not affect the splanchnic extraction of phenylalanine.

Research Methodology

• The study focused on six Thoroughbred mares which were given dietary supplements of isonitrogenous amounts of either threonine or glutamate. The threonine intakes were differentiated as 119 (+Thr) and 58 (Basal) mg/kg/day.
• Each horse was subjected to each diet twice and they were studied once with an oral and once with an intravenous infusion of [1-(13)C]phenylalanine.
• A 2-hour primed, constant intravenous infusion of [(13)C]sodium bicarbonate and a 4-hour primed, constant infusion of [1-(13)C]phenylalanine, either orally or intravenously, were used for measuring the isotopic enrichments.

Outcomes

• The study discovered that phenylalanine kinetics were not impacted by any diet tested (significance value P > 0.05). This signifies that the threonine supplementation showed no significant effect on the functioning of phenylalanine.
• The splanchnic extraction of phenylalanine values were observed to be 26 ± 5% for the +Thr supplemented diet and 27 ± 3% for the Basal supplemented diet, showing not a significant variance.

Impact of the Study

• The findings of this research can be instrumental in advancing future equine indicator amino acid oxidation studies. The acquired values of phenylalanine extraction can enhance the preciseness of these forthcoming studies.