Morphometric changes in the gonads of the West African dwarf bucks experimentally infected with Trypanosoma vivax and Trypanosoma brucei and response due to diminazine aceturate treatment

Abstract

Trypanosomosis, one of the major diseases affecting livestock production in Africa has been associated with reproductive disorders. The disease has not been extensively studied in goats especially the West African Dwarf (WAD) goat. The morphology of the gonads of WAD bucks experimentally infected with Trypanosoma (T.) vivax and Trypanosoma brucei and treatment with Diminazine aceturate were investigated in this study. The study lasted a period of 20 weeks, the first 3 weeks were used to acclimatize the animal to their new environment. The remaining 16 weeks were used to carry out the experiment. Two species of trypanosome were used for the experiment; T. brucei (NITR CT/28- Federe strain) and T. vivax (A field strain obtained from an abattoir). The experiment was divided into three stages tagged Pre-infection (A), infection (B) and treatment (C) while the animals were also divided into control group and infected groups- Trypanosoma brucei and Trypanosoma vivax groups. Biometric parameters that include testicular weight, height and others testicular and epididymal indices were measured according to standard techniques. Data were summarized with mean± SEM and analysed using ANOVA. There were no significant changes in body weight between the control group and treated groups with either T. brucei or T. vivax. The little reduction in scrotal circumference during infection and subsequent increase during post treatment were not significant (P > 0.05) compared to the control. The Testicular weight, testicular length and epididymal weight were not significantly affected during infection with both T. brucei and T. vivax. Tubular diameter and epithelia height of the seminiferous tubules were significantly (P≤0.05) lower in the T. brucei and T. vivax infected groups compared to the control. On the other hand, the epididymal tubular diameter and epididymal epithelia height were not significantly (P>00.05) affected by the treatment. The study showed that the fertility impairment sequel to trypanosomosis is possibly due to alteration in the biometric parameter of the testis.