Epidemiological study on abomasal nematodes in slaughtered small ruminants raised in the guinea savannah zone of Nigeria
Gastrointestinal nematodes are one of the major causes of productivity losses in small ruminants in sub-Saharan Africa. A study was carried out to evaluate the prevalence, worm burden of abomasal nematodes and associated faecal egg counts (FEC) of small ruminants slaughtered from November, 2011 to October, 2012. Two genera of adult abomasal nematodes recovered were Haemonchus spp. and Trichostrongylus spp. Goats had the prevalence of 78.5% and 17.5% for Haemonchus spp and Trichostrongylus spp., respectively while sheep had prevalence of 85% and 31% for Haemonchus spp. and Trichostrongylus spp. A significant difference (p<.005) was observed between host species (goats and sheep), age and sex of animal. There was a seasonal arrest of Haemonchus spp. which was greater during the late dry season than other seasons. Faecal examination revealed Strongyle egg (71% in sheep and 62% in goats) being the most prevalent followed by Strongyloides (8% in sheep and 8.2% in goats) and Trichuris (4% in sheep and 6% in goats) eggs. The mean FEC in sheep for Strongyloides, Strongyle and Trichuris were 4208±343.1, 2966±435.7 and 90±23.80, respectively. The mean FEC in goats for Strongyloides, Strongyle and Trichuris were 2630±138.8, 1301±189.9 and 138.8± 30.39, respectively. The prevalence of worm and FEC showed a definite seasonal sequence that corresponded with the regional relative humidity and rainfall pattern. This knowledge is important for the control of nematode infection in small ruminants in Nigeria.
Keywords: Abomasum, Nematodes, Season, Small Ruminants, Worm burden