Antioxidant and haematological biomarkers in different groups of horses supplemented with polyunsaturated oil and vitamin E.

Oxidative stress has been correlated with pathologies that impair the performance of athlete horses. The aim of this study was to assess the effects of supplementation with a mixture of polyunsaturated oil and vitamin E on the antioxidant and haematological biomarkers of horses. Horses under maintenance care (n = 6) and horses in training (n = 10) received 100 and 300 ml of the oil mixture respectively. Supplementation was provided for a period of 8 weeks, together with isocaloric inclusion. Blood samples were collected at three time periods (pretest, after 4 weeks and after 8 weeks) to analyse the following: the red blood cell count (RBCc); haemoglobin (Hb); haematocrit (HT); leucocytes; lymphocytes; platelets; the mean corpuscular volume (MCV); the mean corpuscular haemoglobin concentration (MCHC); the standard deviation of the red blood cell distribution width (RDW-SD); the coefficient of variation of the red blood cell distribution width (RDW-CV); glutathione peroxidase (GPx); superoxide dismutase (SOD); uric acid (UrAc); total plasma proteins (TPP); and creatine kinase (CK). After the 8 weeks of supplementation, animals under maintenance care exhibited significant increases in SOD, UrAc, the white blood cell count (WBCc), the RDW-SD and the RDW-CV (p < 0.05). The animals in training exhibited increases in GPx, SOD and UrAc (p < 0.05). In conclusion, supplementation with polyunsaturated oil and vitamin E increases blood antioxidants among animals under maintenance and in training, with different trends, while contributing to the fight against oxidative stress in each group analysed.

Metabolic changes in four beat gaited horses after field marcha simulation.

REASONS FOR PERFORMING STUDY: Mangalarga-Marchador is a popular 4-gaited Brazilian horse breed; however, there is little information about their metabolic and physiological response to exercise. OBJECTIVES: To measure physiological and metabolic responses of the Mangalarga-Marchador to a simulated marcha field test and to compare these responses between 2 types of marcha gaits (picada and batida). METHODS: Thirteen horses were used in the study and randomly assigned to either the picada or batida gait for the simulated marcha field test (speed ∼ 3.2 m/s; 30 min; load ∼ 80 kg). MEASUREMENTS: Included body composition, heart rate (HR), respiratory rate (RR), glucose (GLUC), lactate (LACT), packed cell volume (PCV), total plasma protein (TPP), albumin, urea, creatinine, total and HDL cholesterol, triglycerides, creatine kinase, alanine, glutamate and glutamine (GLN). Measurements were obtained pretest (control/fasting), immediately after simulation (T(0)), and 15 (T(15)), 30 (T(30)) and 240 (T(240)) min after the simulation. Lactate (LACT) was measured at T(0), T(15) and T(30). Data were analysed using ANOVA, Tukey's test and t tests with significance set at P < 0.05. RESULTS: Significant acute changes were observed in HR, RR, [GLUC], [LACT], [TPP], PCV and [GLN] (P<0.05) relative to control. Heart rate fell below 60 beats/min at T(15) and RR recovered to pretest values by T(240). Significant increases in [GLUC], [LACT], PCV and [TPP] and a decrease in [GLN] were observed at T(0). Treatment and interaction effects were also observed between marcha types and time of sampling for HR, RF, PCV, and [LACT] (P < 0.05). These parameters were large in picada. CONCLUSION: The simulation of field-test produced changes in some physiological and blood parameters in marcha horses, with some degree of dehydration during recovery period. Also, it was demonstrated that picada horses spend more energy when compared with batida horses at the the same speed. POTENTIAL RELEVANCE: Batida horses spend less energy when compared with picada horses, which will need special attention in their training and nutritional management.