Correlates of Resistance to Gastro-Intestinal Parasites Infection in South African Communal Indigenous Goat Populations

Abstract

The study was conducted to investigate the correlates of resistance to Gastro-Intestinal Parasites (GIPs) infection in South African communal indigenous goat. A total of 288 goats were randomly sampled for fecal and blood collection. Infection intensity was estimated through determining the fecal egg per gram using a modified McMaster technique. Packed Cell Volume (PCV), Hemoglobin (Hgb) and Mean Corpuscular Hemoglobin (MCH) were determined through Auto-Haematology-Analyser BC-2800Vet®. Goat diagnosed free from GIP egg during coprologic evaluation were classified as uninfected, those whose Fecal Egg Count (FEC) were less than 800 as Low Fecal Count (LFEC) phenotype, those with FEC between 800 and 1200 as Intermediate Fecal Egg Count (IFEC) and those that were higher than 1200 as High Fecal Egg Count (HFEC) phenotype. Data were subjected to one-way ANOVA analyses, for dual co-infection, not all comparisons were possible. Pearson’s moment correlation test was computed to determine the relationship between variables. The HFEC phenotyped goats were highly (p<0.05) infected by GIPs followed by intermediate and lastly by LFEC phenotype. Higher (p<0.05) Hgb (10.26 g/dL), PCV (28.51%) and MCH (6.12 pg) were observed in uninfected goats compared to IFEC and HFEC phenotypes. A significant effect of infection status on Hgb and PCV was observed, however, MCH was not influenced (p>0.05). There was a negative relationship (p<0.05) between the Hgb and overall FEC, strongyles and Trichuris spp. intensity. Negative relationship (p<0.05) between PCV and overall FEC and all the GIPs except for Moniezia spp. intensity was evident. The MCH depicted a negative relationship (p<0.05) with Eimeria and Trichuris spp. intensity. The interactions between concomitant GIPs complicates the clinical outcome of infected goats and should be taken into consideration in any study that investigates disease under field conditions. The FECs, Hgb, PCV and MCH are correlates and potential selection criteria of GIP resistant goats.