Effects of dietary supplementation with Erythrina americana on the seminal characteristics of rams

Abstract

Background: The use of antioxidants of natural origin is an alternative to improve the cryopreservation of sheep semen. Objective: To evaluate the effect of Erythrina americana diet supplementation in the seminal characteristics of rams. Methods: Ten rams were randomly distributed in two treatments: l) group with addition of E. americana (20% dry matter basis) in the diet (AEA, n=5), and 2) the control group without addition of E. americana (SEA, n=5). Both diets were balanced iso-proteinically and iso-energetically. The feeding period of the rams was eleven weeks. The ejaculates were obtained through an artificial vagina and were evaluated fresh (37 °C) and refrigerated (5 °C). Volume (VOL) was evaluated with a tube graduated in milliliters, sperm concentration (CON x106) with a photometer and mass motility (MM, 1-5), individual motility (IM), normality (N) and live sperm (L) by microscopic observation. Results: The fresh semen showed that the inclusion of E. americana in the diet of rams did not modify (p>0.05) the parameters of VOL, CON, MM, and N, but decreased (p<0.05) the IM and L. In refrigerated semen the variables L and N were not different (p>0.05) among the treatment groups; however, IM was improved by the AEA group (p<0.05) compared to the SEA group. Conclusion: The supplementation with E. americana in the diet of rams reduces the sperm quality in fresh semen but is beneficial in the cooling process for refrigerated semen.