Haemonchotolerance in West African Dwarf goats: contribution to sustainable, anthelmintics-free helminth control in traditionally managed Nigerian dwarf goats.
Bottom Line: Here, we summarise the history of this breed and explain its economic importance in rural West Africa.If haemonchotolerance can be shown to be genetically controlled, it should be possible to exploit the underlying genes to improve GIN resistance among productive fibre and milk producing breeds of goats, most of which are highly susceptible to nematode infections.Either introgression of resistance alleles into susceptible breeds by conventional breeding, or transgenesis could be used to develop novel parasite-resistant, but highly productive breeds, or to improve the resistance of existing breeds, benefitting the local West African rural economy as well as global caprine livestock agriculture.
Affiliation: Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria.Show MeSH
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Mentions: The third and equally important distinguishing feature of haemonchotolerance is the particularly strong resilience of the goats, especially the strong responder (LFEC) phenotype, to GIN infections, assessed by means of growth rate (Bwt), body condition score (BC) and packed cell volume (PCV). In our experimental infections [13, 14, 16], which usually employed heavy, single, repeated infections, with or without challenge in goat kids, not even the HFEC + high worm burden (500–1070 worms), weak responder phenotypes  showed significant loss of Bwt in both humid (F1,12 = 0.92, P > 0.05) and savannah (F1,12 = 0.02, P > 0.05) WAD goats or clinical evidence of anaemia (PCV ≤ 22%) (Fig. 6). We encountered cases of overt anaemia (PCV ≤ 15%) and correspondingly poor BC scores of 2.0 or less only in a small number (<1%) of naturally infected HFEC savannah WADs . All strong responder goats in naturally acquired infections maintained normal PCV and good Bwt throughout the 6 months of observations. A strong positive correlation was found between PCV and Bwt. Both measures of infection, but particularly PCV, were negatively correlated with FEC and Wb (Fig. 7) and therefore served as additional phenotypic markers of haemonchotolerance.Figure 6.
Affiliation: Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria.