Influence of glutamine and glutamate supplementation in the blood levels of horses

ABSTRACT

Background: The most abundant free amino acid in mammals is glutamine (GLN). Little research has focused on GLNsupplementation for horses, but GLN levels in this species are known to decline after exercise and during lactation. Underphysiological conditions, the body produces Gln in sufficient quantities for general metabolism, and a small part of thisamino acid comes from dietary protein. Little research has so far focused on equine dietary supplementation with freeglutamine or combined with other amino acids during catabolic states or in highly stressful situations. This research wasconducted to evaluate the effects of equine dietary supplementation using a combination of glutamine and glutamate.Materials, Methods & Results: The study involved four Arabian mares, not in training (~380 kg; ~12 years old) and fourtreatments (control, and inclusions of 1, 2 and 4% of GLN+GLU) in a Latin square model. A 7-day washout period wasestablished between each phase. Fifty percent of the mares’ maintenance energy requirements came from concentrate and50% from hay and grazing. The other 50% came from Tifton hay (Cynodon dactylon), which was supplied ad libitum.After 7 weeks of nutritional supplementation (once a day, in the morning). In the experimental model, the mares weredistributed in a Latin square design comprised of four treatments control (without inclusion) and inclusions of 1%, 2%and 4% of supplement (AminoGut®, Ajinomoto do Brazil), and four animals. Blood was collected in five stages (fasting,and 60, 120, 240 and 360 min after feeding) in each treatment. The blood samples were analyzed to determine GLN, GLU,urea, creatinine, uric acid, total plasma protein, hematocrit and glucose levels. Glutamine and Glutamate concentrationswere analyzed using the enzymatic spectrophotometric method. The results were analyzed statistically using one- andtwo-way ANOVA and Tukey’s test with P set at 5%...