Influence of Glutamine and Glutamate Supplementation in the Blood Levels of Horses

Background: The most abundant free amino acid in mammals is glutamine (GLN). Little research has focused on GLN supplementation for horses, but GLN levels in this species are known to decline after exercise and during lactation. Under physiological conditions, the body produces Gln in sufficient quantities for general metabolism, and a small part of this amino acid comes from dietary protein. Little research has so far focused on equine dietary supplementation with free glutamine or combined with other amino acids during catabolic states or in highly stressful situations. This research was conducted 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 four treatments (control, and inclusions of 1, 2 and 4% of GLN+GLU) in a Latin square model. A 7-day washout period was established between each phase. Fifty percent of the mares’ maintenance energy requirements came from concentrate and 50% 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 were distributed 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 concentrations were analyzed using the enzymatic spectrophotometric method. The results were analyzed statistically using one- and two-way ANOVA and Tukey’s test with P set at 5%. The results indicated that GLN differed in both the group (P 0.05). Significant changes in GLN levels were also observed in the 4% inclusion treatment compared to all the treatments in the fasting phase and in the + 60 min and +240 min phases of the control group (P 0.05) during the period under analysis, and remained within the normal range for the species in their current stabling conditions. The mares presented no clinical problems nor did they change their feeding behavior during the supplementation period or on the days blood was collected.Discussion: Glutamine metabolism in horses has yet to be extensively studied.  However, it has been shown that, when supplied to horses in its free form, this amino acid causes Gln levels to rise rapidly within the first 90 min of the postprandial period.  This indicates that an extra amount of this amino acid may increase Gln blood levels despite intense degradation of enterocytes. This study found that supplementation with a combination of Gln+Glu can increase blood Gln levels after 6 h in the treatment involving 4% Gln+Glu included in the concentrate (P < 0.05) In conclusion, supplementation with GLN+GLU raised the mares’ GLN levels after 360 min when 4% of GLN+GLU was included in their diet. These results may be used to establish GLN supplementation models for horses.

New insight on the solidification path of an alloy 625 weld overlay

AbstractNi-based alloys are a special class of engineering material with excellent corrosion resistance in harsh environments. However, microstructural changes due to the solidification, may result in solidification cracks and reduction in the corrosion resistance. Knowing the microchemical and microstructural evolutions during the solidification of these alloys is essential for the understanding of the relationship between the metallurgical aspects and the properties. This research presents a new insight on the solidification path of alloy 625 weld metals deposited by the TIG cold wire process on the C–Mn steel plates. After the welding, samples having been extracted and evaluated by the scanning electron microscope, transmission electron microscopy and energy dispersive X-ray spectroscopy techniques. The results showed the presence of two types of secondary phases, identified as Laves phase and complex nitride/carbide particles. Due to the presence of nitrides particles, stable in the solid state during the melting of the alloy, during the solidification it is noted the occurrence of a complex nitride/carbide precipitation. This implies in a new route to explain the solidification of the aforementioned alloy

Evaluation of Mangalarga Marchador foal development in the first year of life

The purpose of this study was to examine the development pattern of Mangalarga-Marchador foals by determination of muscle development and deposition of adipose tissue associated with the evaluation of blood-based biomarkers. Thus, 72 Mangalarga Marchador foals (ages ranged from 1-12 mo) were randomly selected and divided into 12 age groups (n=6 per group), evaluated monthly. The thickness of the Longissimus dorsi (LD) and rump fat (RF) were determined through an ultrasound performed on each foal’s left side. Such parameters were used to calculate the percentage of body fat (BF), fat mass (FM), and fat-free mass (FFM). Morphometric measurements were taken on the foal’s right side using a tape measure and a hypsometer. Blood samples were collected for determinations of total proteins, albumin, triglycerides, cholesterol, urea, creatinine, and glucose. Morphometric measurements,  the thickness of the LD and RF, weight, BF, FM, and FFM showed differences between age groups (P&lt;0.001). Muscle development and fat deposition in subcutaneous tissue were greater between six and 12 months and average weight gain and FFM were proportionally greater between one and six months. We concluded that morphometric measurements increase steadily and linearly during the first 12 months of life, indicating that it is feasible to use the linear regression formula. Moreover, significant differences between age and biochemical biomarkers may be attributed to nutritional and digestive physiology adaptations during these periods.O objetivo desse estudo foi examinar o padrão de desenvolvimento de potros Mangalarga Marchador através da determinação do desenvolvimento muscular e da deposição de tecido adiposo associado com avaliação de biomarcadores sanguíneos. Assim, 72 potros Mangalarga Marchador (idades entre 1 e 12 meses) foram selecionados ao acaso e divididos em 12 grupos etários (n=6/grupo), avaliados mensalmente. A espessura do Longissimus dorsi (LD) e da cobertura de gordura da garupa (RF) foi determinada através de ultrassonografia realizada do lado esquerdo de cada animal, tais parâmetros foram usados para calcular percentagem de gordura corporal (BF), massa de gordura (FM) e massa livre de gordura (FFM). Mensurações morfométricas foram obtidas do lado direito de cada potro, usando fita métrica e hipômetro. Amostras sanguíneas foram obtidas para determinações de proteínas totais, albumina, triglicérides, colesterol, uréia, creatinina e glicose. Medidas morfométricas, espessura de LD e RF, peso corporal, BF, FM e FFM mostraram diferenças entre os grupos etários (P&lt;0,001). O desenvolvimento muscular e a deposição de gordura no tecido subcutâneo foram maiores entre 6 e 12 meses e a média de ganho de peso e de FFM foi proporcionalmente maior entre entre 1 e 6 meses . Foi possível concluir que as medidas morfométricas aumentam de forma constante e linear nos primeiros 12 meses de vida, indicando que é factível usar fórmulas de regressão linear. Ainda, diferenças significativas entre idade e biomarcadores bioquímicos podem ser atribuídos às adaptações nutricionais e digestivas durante esses períodos.

Metabolic and physiological changes during and after vaquejada exercise in horses

Physiological and metabolic evaluations of equine sports have been conducted to define parameters or biomarkers for performance evaluation, clinical diagnosis and predict fatigue and overtraining. Actually, the vaquejada is the most important equine sport in Brazil, and these horses are repeatedly submitted to shortduration physical exertion, during 2 or 3 alternate or consecutive days, requiring adequate conditioning for this equestrian modality. The objective of this study was to test the hypothesis that pulls horses and helper horses undergo physiological and metabolic changes during vaquejada races. Eighteen Quarter Horses were used, including 12 pull horses and 6 helper horses. Hemograms and the following analyses were performed: glucose, lactate, cholesterol, triglycerides, NEFA, total proteins, albumin, creatine kinase, gama glutamyl transferase and cortisol. A heart rate monitor was used to measure the heart rate, velocity and travel distance of each animal. Statistical analyses were performed using ANOVA and Tukey's tests, with P established at 5%. Pull horses had higher heart rate values, but the velocities attained by the two groups of horses were similar. There was an increase in heart rate, glucose, lactate, non-esterified fatty acids and cortisol in both pull and helper horses after racing, but these levels returned to resting values 30 minutes after the end of exercise. It was concluded that the vaquejada field test promoted significant changes in haematological, biochemical biomarkers and in the heart rate of both groups of horses