Haematological responses of three Nigerian goat breeds to field acquired helminthes infection and their haemoglobin types

Abstract

Response of goats to natural helminth infection was investigated among 277 Nigerian indigenous goats belonging to three different breeds [West African dwarf (WAD), Red Sokoto (RS) and Sahel White (SW)] through the
determination of parasitological and haematological parameters. The results showed that 65% of the sampled animals were positive for one helminth or two. Mixed infection due to Haemonchus contortus and Trichostrongylus colubriformis constituted 33.33% prevalence rate, while Haemonchus contortus and Oesophagostomum columbianum mixed infection had 26.67% rate of infection among the sampled animals. However, single infection due to either of Haemonchus contortus,  Oesophagostomum columbianum, Trichostrongylus colubriformis,  Strongyloides papilosus, Cooperia punctata, Trichuris ovis,  Paramphistomum cervi and Moniezia benedini constituted 5.0%. There was no significant (p>0.05) difference in mean faecal egg count (FEC) among the breeds investigated. Similarly, correlation  coefficient between  Haemonchus worm count (HWC) and FEC showed positive correlation value which was significantly (p<0.01) higher among WAD (0.661) than SW (0.427) and RS (0.350) breeds. Three (3) different haemoglobin types (HbAA, HbAB and HbBB) were detected among the goats investigated. Goats with HbAA showed significantly (p<0.05) higher PCV compared to those with HbAB/HbBB alleles. In addition, Sahel White and Red Sokoto breeds had microcytic, hypochromic anaemia with a significantly (p<0.05) lower haematocrit values than the West African Dwarf breed. Eosinophil count of RS and SW goats did not vary significantly between the parasitized and the non-parasitized goats. However, in WAD, the eosinophil count was significantly higher (p<0.05) in parasitized than non-parasitized goats. In conclusion, the WAD breed appears to be more resistant to helminthes infections and H. contortus in particular, than RS and SW, and this may be due to high frequency of HbAA alleles in this breed. The advantage of this relative resistance could be exploited by crossbreeding WAD with other breeds.

KEYWORDS: Nigerian goats, Field helminthosis, Haematology, Faecal egg counts, Haemoglobin types.