Glutamine and pyruvate as metabolic substrates in seminal diluents for preserving the fertility of chilled equine semen.
Stallion, cryotolerance, fertility, sperm metabolism
Refrigeration of equine semen is a widely used tool in assisted reproduction; however, the progressive reduction in fertility during storage still represents a significant technical challenge. Therefore, this study aimed to develop a diluent supplemented with glutamine and pyruvate for equine semen refrigeration, with an emphasis on increasing the fertility potential of refrigerated equine semen. The formulation was structured to combine membrane protection, metabolic support, and control of oxidative stress, factors directly related to maintaining the fertilizing capacity of spermatozoa.The diluent's efficiency was evaluated through the analysis of classic and functional sperm parameters, including sperm kinetics, after different refrigeration periods. The results demonstrated that supplementation with energy and bioactive substrates favored the maintenance of metabolic activity, reflecting in greater functional stability and preservation of characteristics directly associated with fertility. Therefore, it is concluded that the developed diluent has potential for increasing the longevity and maintaining the fertilizing capacity of refrigerated equine semen, constituting a promising alternative for improving fertility rates in artificial insemination programs and for advancing reproductive biotechnologies in equine breeding.