The effect of different levels of crude protein on the pathophysiology of Haemonchus contortus infection in 2-year-old Boer dry does under confined conditions

Abstract

The effect of dietary protein supplementation on the pathophysiology of a single Haemonchus contortus infection in 2-year-old Boer dry does under confined conditions was examined. Twenty-four does were randomly confined in individual pens and allocated into three groups balanced by their liveweight. The goats in the Control group were offered a basal diet whereas goats in Treatments 1 and 2 were fed the basal diet plus 25% and 50% dietary protein increments, respectively. Each animal was orally administrated 100 H. contortus L3 larvae/kg liveweight on Day 0 of the experiment. The goat liveweights and FAMACHA scores were recorded at weekly intervals. Packed cell volumes, eosinophil percentage, haemoglobin concentration, total serum protein, globulin, and albumin concentrations were recorded on Days 0 and 14, and then at weekly intervals during the experiments. Faecal egg counts were measured on Days 0, 21, and then at weekly intervals thereafter. Antigen-specific IgA, IgG, and IgM titres were determined from Enzyme-linked immunosorbent assays tests on Days 0, 28, and at the termination of the experiment. The results of this study showed that a single H. contortus L3 infection did not cause pathogenic effects in 2-year-old Boer dry does. Dietary protein supplementation significantly lowered faecal egg count and significantly enhanced IgG titres (P < 0.05). However, the higher protein diets did not have any significant effects on liveweight, packed cell volumes, haemoglobin concentration, biological parameters (total serum protein, albumin, and globulin concentrations), and peripheral antibodies (IgA and IgM titres) between the treatments. Further investigations are required to clarify the role of protein supplementation to control H. contortus infection in goats.