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Research (Published online: 23-07-2016)

14. Testicular pathology, gonadal and epididymal sperm reserves of Yankasa rams infected with experimental Trypanosoma brucei brucei and Trypanosoma evansi - Yunusa A. Wada, Sonnie J. Oniye, Peter I. Rekwot and Oluyinka O. Okubanjo

Veterinary World, 9(7): 759-765



   doi: 10.14202/vetworld.2016.759-765



Yunusa A. Wada: Department of Biological Sciences, Faculty of Science, Ahmadu Bello University, Zaria, Nigeria;

Sonnie J. Oniye: Department of Biological Sciences, Faculty of Science, Ahmadu Bello University, Zaria, Nigeria;

Peter I. Rekwot: National Animal Production Research Institute, Ahmadu Bello University, P.M.B. 1096 Shika, Zaria, Nigeria;

Oluyinka O. Okubanjo: Department of Veterinary Parasitology and Entomology, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria;


Received: 17-12-2015, Accepted: 09-06-2016, Published: 23-07-2016


Corresponding author: Yunusa A. Wada, e-mail:

Citation: Wada YA, Oniye SJ, Rekwot PI, Okubanjo OO (2016) Testicular pathology, gonadal and epididymal sperm reserves of Yankasa rams infected with experimental Trypanosoma brucei brucei and Trypanosoma evansi, Veterinary World, 9(7): 759-765.

Aim: The study was conducted to evaluate the pathological effects of trypanosomosis on the testes, gonadal, and epididymal sperm reserves of Yankasa rams for 98 days.

Materials and Methods: A total of 16 Yankasa rams, aged between 24 and 30 months and weighed between 22 and 25 kg, were acclimatized for a period of 2-months in a clean fly proof house and were adequately fed and given water ad-libitum. Of the 16 rams, 12 that were clinically fit for the experiment at the end of the acclimatization period were randomly divided into four groups: Groups I, II, III, and IV, each having 3 rams. Groups I and II were each challenged singly with experimental Trypanosoma brucei brucei (Federer strain) and Trypanosoma evansi (Sokoto strain), respectively, while Group III was challenged with mixed T. brucei brucei and T. evansi parasites (50% of each species in the infective inoculum) and Group IV was left as an uninfected control. Each infected ram received 2 mL of the infected blood containing 2×106 trypomastigotes via the jugular vein, while the control group received 2 mL each, normal saline.

Results: All the infected rams developed clinical signs typical of trypanosomosis at varying pre-patent periods. The gross lesions observed in the infected rams in Group II were moderate and more severe in those of Groups I and III. Histological sections of the testes of infected rams (Groups I, II, and III) showed moderate (T. evansi-infected group) to severe (mixed and T. brucei brucei-infected groups) testicular degenerations with reduction in number of spermatogenic cell layers, degenerated seminiferous tubules, congested interlobular spaces, loss of tissue architecture with significant (p<0.01) depletion, and loss of gonadal and epididymal sperm reserves in Groups I and III in comparison to Group II and the control Group IV. No observable clinical signs and histopathological lesions were found in those rams of the control Group IV.

Conclusion: The study concluded that trypanosomosis due to experimental T. brucei brucei or T. evansi or mixed infections (of both parasites) caused testicular damage, decreased epididymal and gonadal sperm reserves and an important cause of infertility in Yankasa rams.

Keywords: gonadal sperm reserve, mixed infection, testicular degeneration, Trypanosoma brucei brucei, Trypanosoma evansi, Yankasa ram.

1. Soudre, A., Ouedraogo-Kone, S., Wurzinger, M., Muller, S., Hanotte, O., Ouedraogo, A.G. and Solkner, J. (2013) Trypanosomosis: A priority disease in tsetse challenged areas of Burkina Faso. Trop. Anim. Health Prod., 45(2): 497-503.
2. Batista, J.S., Rodrigues, C.M.F., Olinda, R.G., Silva, T.M., Vale, R.G., Câmara, A.C., Reboucas, R.E., Bezerra, F.S., García, H.A. and Teixeira, M.M.G. (2012). Highly debilitating natural Trypanosoma vivax infections in Brazilian calves: Epidemiology, pathology and probable transplacental transmission. Parasitol. Res., 110: 73-80.
3. Silva, T.M., Olinda, R.G., Rodrigues, C.M., Camara, A.C., Lopes, F.C., Coelho, W.A., Ribeiro, M.F., Freitas, C., Teixeira, M.M. and Batista, J.S. (2013) Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes. Vet. Res., 44(1): 1-5.
PMid:23289625 PMCid:PMC3598889
4. Mbaya, A.W., Nwosu, C.O. and Kumshe, H.A. (2011) Genital lesions in male red fronted gazelles (Gazella rufifrons) experimentally infected with Trypanosoma brucei and the effect of melarsamine hydrochloride (Cymelarsan®) and diminazene aceturate (Berenil®) in their treatment. Theriogenology, 16: 721-728.
5. Okubanjo, O.O., Sekoni, V.O., Ajanusi, O.J., Nok, A.J. and Adeyeye, A.A. (2014) Testicular and epididymal pathology in Yankasa rams experimentally infected with Trypanosoma congolense. Asian Pac. J. Trop. Dis., 4(3): 185-189.
6. Bezerre, F.S.B., Garcia, H.A., Alves, H.M., Oliveira, I.R.S., Silva, A.E., Teixeira, M.M.G. and Batista, J.S. (2008) Trypanosoma vivax in testicular and epidydimal tissues of experimentally infected sheep. Pesq. Vet. Bras., 28: 575-582.
7. Ikede, B.O. and Akpavie, S.O. (1982) Delay in resolution of trypanosome induced genital lesions in male rabbit infected with Trypanosoma brucei and treated with Diminazene aceturate. Res. Vet. Sci., 32: 374-376.
8. Omeke, B.C. and Igboeli, G. (2000) Disruption of spermatogenesis in boars sub-clinically infected with Trypanosoma brucei. Anim. Reprod. Sci., 63: 197-204.
9. Sekoni, V.O., Rekwot, P.I. and Bawa, E.K. (2004) The effect of trypanosomosis on sperm morphology in Zebu x Friesian crossbred bulls. Trop. Anim. Health Prod., 36: 55-64.
10. Sekoni, V.O. (1992) Effect of Trypanosoma vivax infection on semen characteristics of Yankasa rams. Br. Vet. J., 148: 501-506.
11. Wilson, R.T. and Durkin, J.W. (1984) Age at permanent incisor eruption in indigenous goats and sheep in semi-arid Africa. Small Ruminant and Camel Group, Group Document No. SR C3. International Livestock Centre for Africa, Addis Ababa. p451-455.
12. Woo, P.T.K. (1969) The haematocrit centrifuge technique for the detection of trypanosomes in blood. Can. J. Zool., 47: 921-923.
13. Biryomumaisho, S., Rwakishaya, E.K., Melville, S.E., Cailleau, A. and Lubega, G.W. (2013) Livestock trypanosomosis in Uganda: Parasite heterogeneity and anaemia status of naturally infected cattle, goats and pigs. Parasitol. Res., 112(4): 1443-1450.
14. Hoare, C.A. (1972) Trypanosomes of Mammals: A Zoological Monograph. Blackwell Scientific Publications, Oxford and Edinburgh. p1-3.
15. Herbert, W.J. and Lumsden, W.H.R. (1976) Trypanosoma brucei: A rapid "matching" method for estimation of the host parasitaemia. Exp. Parasitol., 40(3): 427-431.
16. Rekwot, P.I., Oyedipe, E.O. and Ehoche, G.W. (1994) The effects of feed restriction and realimentation on the growth and reproductive function of Bokoloji bulls. Theriogenology, 42: 287-295.
17. Ogunlade, J.T., Ewuola, E.O., Gbore, F.A., Bandyopadhyay, R., Niezen, J. and Egbunike, G.N. (2006) Testicular and epididymal sperm reserves of rabbits fed fumonisin contaminated diets. World Appl. Sci. J., 1(1): 35-38.
18. Coles, E.H. (1986) Veterinary Clinical Pathology. 4th ed. WB. Sounders Company, Philadelphia, London, Toronto, Mexico City Rio de Janeiro, Sydney, Tokyo Hong Kong. p486.
19. Luna, L.G. (1968) Manual of Histologic Staining Methods of the Armed Forces Institute of Pathology. 3rd ed. McGraw-Hill Book Company, New York.
20. Sekoni, V.O., Njoku, C.O., Kumi-Diaka, J. and Saror, D.I. (1990) Pathological changes in male genitals of cattle infected with Trypanosoma vivax and Trypanosoma congolense. Br. Vet. J., 146: 175-180.
21. Steel, R.G. and Torrie, J.H. (1980) Principles and Procedures of Statistics: An Approach. 2nd ed. McGraw-Hill Book Co. Inc., New York.
22. Adamu, S., Fatihu, M.Y., Useh, N.M., Mamman, M., Sekoni, V.O. and Esievo, K.A.N. (2007) Sequential testicular and epididymal damage in Zebu bulls experimentally infected with Trypanosoma vivax. Vet. Parasitol., 43: 29-34.
23. Anosa, V.O. and Isoun T.T. (1980) Further observations of the testicular pathology in Trypanosoma vivax infection in sheep and goats. Res. Vet. Sci., 28: 151-160.