Resistance and resilience of traditionally managed West African Dwarf goats from the savanna zone of northern Nigeria to naturally acquired trypanosome and gastrointestinal nematode infections

• Published in: Journal of helminthology 2011-03, Vol.85 (1), p.80-91
• Main Authors: Behnke, J.M., Chiejina, S.N., Musongong, G.A., Nnadi, P.A., Ngongeh, L.A., Abonyi, F.O., Fakae, B.B.
• Format: Article
• Language: English
• Subjects: Animal Husbandry - methods; Animals; Biological and medical sciences; Feces - parasitology; Female; Fundamental and applied biological sciences. Psychology; Gastrointestinal Tract - immunology; Gastrointestinal Tract - parasitology; Goat Diseases - diagnosis; Goat Diseases - epidemiology; Goat Diseases - immunology; Goat Diseases - parasitology; Goats; Haemonchus; Host parasite relation; pathogenicity; Invertebrates; Male; Mammalia; Nemathelminthia. Plathelmintha; Nematoda; Nematoda - classification; Nematoda - isolation & purification; Nematode Infections - epidemiology; Nematode Infections - immunology; Nematode Infections - parasitology; Nematode Infections - veterinary; Nigeria - epidemiology; Parasite Egg Count; Strongylida - isolation & purification; Strongylida - pathogenicity; Strongylida Infections - diagnosis; Strongylida Infections - epidemiology; Strongylida Infections - parasitology; Strongylida Infections - veterinary; Trichostrongylus; Trypanosoma; Trypanosoma - classification; Trypanosoma brucei; Trypanosoma brucei brucei - isolation & purification; Trypanosomiasis - diagnosis; Trypanosomiasis - epidemiology; Trypanosomiasis - immunology; Trypanosomiasis - parasitology; Trypanosomiasis - veterinary; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution
• ISSN: 0022-149X; 1475-2697
• DOI: 10.1017/S0022149X10000295

A survey was conducted of gastrointestinal nematode infections and trypanosomosis in Nigerian West African Dwarf (WAD) goats from the savanna region of the country. Animals were screened at two markets, Gboko and Akpagher, from the beginning of April until the end of September, coinciding with the end of the dry season and the first 5 months of the wet season. Of 1054 goats that were examined, 80.5% carried gastrointestinal (GI) nematodes belonging to the genera Haemonchus (61.0%), Oesophagostomum (21.0%) and Trichostrongylus (17.9%). Faecal egg counts (FEC) increased very slowly but significantly from April to maximum levels in September, and varied marginally between the two market sources. The majority of goats (68.8 and 70.1% at the two markets) had low FEC not exceeding 50 eggs/g (epg). FEC did not differ significantly between the sexes or between age classes. Packed cell volume (PCV) also declined significantly with month of the study, but was affected by host sex (a significant month × sex interaction) being generally higher in male animals throughout the period. There was a highly significant negative correlation between log10(FEC+1) and PCV, when all other factors had been taken into account. Body condition scores (BCS) also declined with month of the study, but there was a marked difference between the two sexes, with male animals generally showing a greater stability of BCS across the months compared with females. Trypanosome infections were found in only 4% of the goats and only during the rainy season. Most infections (92.86%) were caused by Trypanosoma brucei alone although T. vivax and T. congolense were occasionally detected. Overall, the majority of goats sampled each month maintained generally good body condition (BCS 3.0–5.0), normal or slightly reduced PCV, even when concurrently infected with trypanosomes and GI nematodes. However, four concurrently infected goats showed signs of overt anaemia during periods of peak infection, during the late rainy season, with marked reductions in PCV (