RESUMO
Taurine bulls are highly susceptible to heat stress, leading to increased oxidative stress (OS) and impaired sperm viability. Polyunsaturated fatty acids (PUFAs) supplementation can be an alternative to improve semen quality, which also results in more sperm susceptibility to lipid peroxidation. Moreover, this deleterious effect can be exacerbated in animals affected by heat stress. Vitamin E is a key antioxidant that counteracts lipid peroxidation of sperm membrane caused by OS. Thus, combining PUFAs with vitamin E may improve sperm quality. In this context, this study aimed to evaluate the effect of interaction between PUFAs and vitamin E on sperm quality in Bos taurus bulls under testicular heat stress. Sixteen taurine bulls under testicular heat stress were randomly assigned in four groups: Control, Vitamin E, PUFA, and PUFA + Vitamin E. All groups lasted for 60 days. Samples were cryopreserved/thawed and analyzed for motility variables (CASA), membrane and acrosome integrity, mitochondrial activity, susceptibility to oxidative stress, DNA integrity, and sperm-binding capacity. Results showed that vitamin E had a beneficial effect on some sperm characteristics, whereas PUFA supplementation had an adverse effect when the two treatments were evaluated separately. Finally, the association between PUFAs and vitamin E did not improve sperm quality.