Physical characteristics and microbial load of chilled Holstein bull semen diluted in propolis contained extender

الملخص EN

The current pilot study was carried out to evaluate the efficiency of supplementing bovine semen extender with propolis extract on cooled semen physical characteristics and microbial contamination.

Six Holstein Friesian bulls aged 4-6 years, and average body weights of 1041.7±58.3 Kg were used.

Eighteen ejaculates were collected from the bulls (3 ejaculates each).Thereafter, the ejaculates were pooled and diluted.

The pooled specimens were further split into the following five groups: control, 1ml/L streptomycin sulfate plus 1000000 IU penicillin, 5μL/ml propolis extract, 10μL/ml propolis extract, 20μL/ml propolis extract.

All semen groups were subjected to cooling preservation for 48h at 5°C, during which sperm physical properties were evaluated.

Formation of total colony forming unite (CFU) was also determined.

The results showed that propolis extract supplementation improved (P<0.05) all sperm physical characteristics, in a dose – depending manner, over preservation time.

Further, the control group exhibited total CFU higher (P<0.05) than all treated specimens.

These results imply the possibility of using propolis extract as a sufficient alternative to conventional synthetic antibiotics in bovine semen extenders.