R.E. Ere - Department of Animal Science, Faculty of Agriculture, University of Benin, Nigeria
J.A. Imasuen - Department of Animal Physiology, College of Animal Science and livestock production, Federal University of Agriculture, Abeokuta, Nigeria
A.A. Ere-Richard - higher institution , Nigeria

This study investigated the additive effect of ethanolic extract of Black Pepper (Piper nigrum) on gonadosomatic index of the testes and testicular histology as well as testicular morphometry of Rabbit bucks. A total of twenty (۲۰) composite Rabbit bucks aged ۱۸ – ۲۰ weeks were used for this study in a completely Randomized design. Experimental animals were divided into ۵ groups represented as A, B, C, D, and E consisting of ۴ bucks each and replicated four (۴) times with a buck per replicate. The first group A (Control) was given pelleted feed that did not contain extract of black pepper. The second, third, fourth and fifth groups (B, C, D, E) had in their diet (pelleted feed) inclusion levels of black pepper extract at ۱۰۰mg/kg feed, ۱۵۰mg/kg feed, ۲۰۰mg/kg feed (optimum) and ۲۵۰mg/kg feed (above optimum). The treatment (test diet) was administered for ۹۰ days. Ethanolic extract of Black pepper inclusion at optimum and above optimum showed statistical evidence of higher values for optimum and lower values for above optimum. Testicular length of Rabbits fed at optimum and above optimum showed (۶.۹۰۰±۰.۲۰) and (۶.۰۶۷±۰.۲۰), testes weight showed (۴.۴۷±۰.۴۰) and (۱.۶۳±۰.۴۰), testes volume showed (۲.۵۳±۰.۲۳) and (۰.۹۰±۰.۲۳), epididymis length showed (۲۳.۲۳±۰.۹۷) and (۱۸.۷۳±۰.۹۷), and gonadosomatic index results showed (۰.۱۲۵۷±۰.۰۱) and (۰.۰۴۸۳±۰.۰۱). Black pepper ethanol extract enhanced testicular morphometric parameters of Rabbit bucks fed at optimum inclusion level of ۲۰۰mg/kg feed. It was also observed to be toxic to testis development at higher doses (above optimum) based on the Gonadosomatic index results, and testicular histological slides showed that inclusion levels of ethanolic extract of Black pepper above optimum levels causes destruction of seminiferous tubules and negatively affected spermatogenesis.This study investigated the additive effect of ethanolic extract of Black Pepper (Piper nigrum) on gonadosomatic index of the testes and testicular histology as well as testicular morphometry of Rabbit bucks. A total of twenty (۲۰) composite Rabbit bucks aged ۱۸ – ۲۰ weeks were used for this study in a completely Randomized design. Experimental animals were divided into ۵ groups represented as A, B, C, D, and E consisting of ۴ bucks each and replicated four (۴) times with a buck per replicate. The first group A (Control) was given pelleted feed that did not contain extract of black pepper. The second, third, fourth and fifth groups (B, C, D, E) had in their diet (pelleted feed) inclusion levels of black pepper extract at ۱۰۰mg/kg feed, ۱۵۰mg/kg feed, ۲۰۰mg/kg feed (optimum) and ۲۵۰mg/kg feed (above optimum). The treatment (test diet) was administered for ۹۰ days. Ethanolic extract of Black pepper inclusion at optimum and above optimum showed statistical evidence of higher values for optimum and lower values for above optimum. Testicular length of Rabbits fed at optimum and above optimum showed (۶.۹۰۰±۰.۲۰) and (۶.۰۶۷±۰.۲۰), testes weight showed (۴.۴۷±۰.۴۰) and (۱.۶۳±۰.۴۰), testes volume showed (۲.۵۳±۰.۲۳) and (۰.۹۰±۰.۲۳), epididymis length showed (۲۳.۲۳±۰.۹۷) and (۱۸.۷۳±۰.۹۷), and gonadosomatic index results showed (۰.۱۲۵۷±۰.۰۱) and (۰.۰۴۸۳±۰.۰۱). Black pepper ethanol extract enhanced testicular morphometric parameters of Rabbit bucks fed at optimum inclusion level of ۲۰۰mg/kg feed. It was also observed to be toxic to testis development at higher doses (above optimum) based on the Gonadosomatic index results, and testicular histological slides showed that inclusion levels of ethanolic extract of Black pepper above optimum levels causes destruction of seminiferous tubules and negatively affected spermatogenesis.

Histology, Morphometry, Piper nigrum, Rabbit, Spermatogenesis, Testes