Hematological and biochemical values in Brazilian four-beat gaited horses

Horse selection is still associated with gait type, and this aspect is important for four-beat gaited horses, a large group that is distributed around the globe with more than 140 breeds. However, there is little information about their hematological and biochemical profiles, and such information will contribute to improving their exercise and nutritional evaluation programs. The aim of this study was to determine the hematological and biochemical values of athletic Campolina (CAMP) and Mangalarga Marchador (MM) horses performing two different types of gait. Overall, 100 adult horses (53 males and 47 females) with ages between 5 and 15 years and body weights between 350 and 550 kg were evaluated. The horses were grouped as follows: 25 Campolina marcha batida (CAMP-batida), 25 Campolina marcha picada (CAMP-picada), 25 Mangalarga Marchador marcha batida (MM-batida), and 25 Mangalarga Marchador marcha picada (MM-picada). They were fed fresh elephant grass (Pennisetum purpureum Schum; ~15–20 kg/day) and commercial concentrate (5–7 kg/day) as well as commercial mineral salt and water ad libitum. They were trained three times a week (~40–50 min/day), and ~60% of the sessions involved speeds ranging from 3.0 to 4.0 m/s. The results of hematological and biochemical tests were analyzed with ANOVA and Tukey’s test (P ≤ 5%). The results showed no differences in the hematological values that were found between the CAMP and MM horses, even when they were grouped by gait. In contrast, differences in the biochemical values were observed between the groups for triglycerides, cholesterol, non-esterified fatty acids, total plasma protein, urea, creatinine, uric acid, alanine aminotransferase, and creatine kinase (P < 0.05). The highest values were recorded in the following groups: CAMP-batida (triglycerides ~33.77 mg/dL, urea ~35.88 mg/dL, and uric acid ~2.11 mg/dL), CAMP-picada (creatinine ~1.44 mg/dL), and MM-batida (cholesterol ~95.77 mg/dL, non-esterified fatty acid ~0.35 mmol/L, total plasma protein ~10.00 mg/dL, ALT ~11.30 U/L, and CK ~198.80 U/L). In conclusion, despite having different gaits, there were no differences in hematological parameters between Campolina and Mangalarga Marchador horses; however, biochemical values associated with fat and protein metabolism were significantly different between the groups.