Effect of preputial washing and antibiotic treatment on bacterial load and preservability of frozen bovine semen*

Abstract

Preputial cavity is a main source of microbial contamination in semen. The semen samples were collected from 24 bovine bulls and extended with egg yolk citnite and treated with various combinations of antibiotics at different dose level. The different combinations were streptomycin + benzyl penicillin, streptomycin + benzyl penicillin + gentamicin, streptomycin + benzyl penicillin + ampicillin. Preputial washing was given by the antibiotic solution containing procaine penicillin. Without preputial washing, ejaculate from the same bull was taken as control. The effect of cryopreservation had a significant (P<0.01) influence on individual motility of spermatozoa, non-eosinophilic count, sperm abnormalities, acrosomal integrity and on total bacterial count. The treatment with different combinations of antibiotic on bacterial count was highly significant (P<0.01). Preputial washing significantly (P<0.01) reduced the total bacterial count. The effect of different combinations of antibiotic treatment on individual motility of spermatozoa, non-eosinophilic count, abnormal spermatozoa and acrosomal integrity of sperm cells was non-significant. The maximum reduction of bacterial count was observed by streptomycin + penicillin. + gentamicin combination and followed by other combinations. The preputial washing coupled with streptomycin + penicillin + gentamicin fortification was the most efficient treatment for reducing bacterial load to 'a greater extent without affecting semen quality and preservability.