Spermatic quality and plasmatic lipids in stallions supplemented with rice bran oil semirefined containing high level of gamma-oryzanol

Abstract

Gamma-oryzanol is a natural substance contained in rice bran oil that has been studied for years in humans due to its hypocholeterolemic and antioxidant properties, and in recent years in horses. Using six stallions from different breeds in a randomized experimental design, weighing 472.67±90.48 kg and aging 10±5.4 years, this study was aimed to evaluate the effects of supplementation with rice bran oil containing 1.1% of gamma-oryzanol in plasmatic lipids levels (total cholesterol, HDL-C, LDL-C, VLDL-C and triglycerides), testosterone and sperm quality. Stallions were divided in two groups, one receiving 150 mL of soybean oil, and the other 150 mL of rice bran oil twice a day, during 60 days. Blood and sperm samples were collected every 15 days of the trial period. Data obtained was processed, and means compared using F test, at 5% of confidence level. Mean values of total cholesterol, HDL-C, LDL-C, VLDL-C, triglycerides and testosterone were respectively 92.73; 61.47; 26.99; 4.28 mg/dL and 75.93 ng/dL in the soybean oil supplemented group, and 110.20; 66.73; 38.44; 5.02 mg/dL and 62.13 ng/dL in the rice bran oil one. No difference among treatments (p<0,05) were observed in sperm quality parameters volume, motility, concentration and defects. Supplementation of stallions with rice bran oil containing 1.1% of gamma-oryzanol do not promote any change in sperm quality, testosterone, HDL-C, VLDL-C or triglycerides plasmatic levels, but an increase in total cholesterol and LDL-C.