Freezing and Fertilizing Abilities of Summer Semen of Egyptian Buffalo (Bubalus bubalis) Bulls Using Moring Extract as Antibiotic or as a New Promising Extender

Abstract

Semen collection is the business for various artificial insemination organizations, hence the management of entire process of collection is quite critical. Therefore, the trend now is to design procedures or refine methodologies so as to maximize the production of good quality semen without discarding too many poor quality ejaculates. The present work aimed to study the effect of seasons (winter vs. summer) on buffalo semen characteristics, and evaluating the freezing ability and fertilizing ability of buffalo semen collected in summer and extended with ethanolic Moringa oleifera leaf extract (eMOLE) natural antibiotics and antioxidant in extender. Semen was collected twice weekly by artificial vagina from four healthy matured buffalo bulls (400-450 kg body weight 4-5 years old) during winter and summer seasons for 10 weeks in winter (Dec-February) and in summer (July-August). Ejaculates were evaluated for some semen characteristics during both seasons (1st experiment). In the 2nd experiment, only ejaculates of ≥70% as initial sperm motility were extended by citrate egg yolk (CEY), eMOLE as anti-biotics in CEY (CEYm), eMOLE and cryopreserved in liquid nitrogen (-196oC). Post-thawed semen was evaluated physically and chemically, and pregnancy rate as done as a fertility study. Results show that ejaculate volume, and percentages of live, acrosome integrity, and membrane integrity, increased (P˂0.05) in summer compared with winter. However, the effect of season on semen density, and motility and abnormal sperm percentages was not significant. Extension of semen by eMOLE resulted improving (P<0.05) percentage of sperm motility, livability, abnormality and intact acrosome in post-thawed semen. Also, enzyme activities (AST, ALT and LDH) reduced to the minimal levels in seminal plasma of post-thawed semen with eMOLE. Replacing antibiotics in CEY extender by eMOLE (4 ml/100 ml) had no significant effect on all sperm characteristics and enzyme activity. Semen extended with eMOLE showed significantly (P<0.05) higher fertility rate (83.3%) than that extended with CEY or CEYm (66.6%, P<0.05). In conclusion, buffalo semen collection during summer months (July-August) in Egypt can be used for insemination in association with better quality than that of winter semen. From the economical point of view, eMOLE is considered as a new promising extender and as an alternative for anti-biotic and efficient antioxidant in extenders of buffalo semen collected and cryopreserved during summer.