Influence of dietary supplementation with Acacia karroo on experimental haemonchosis in indigenous Xhosa lop-eared goats of South Africa

Abstract

The effect of dietary supplementation with fresh Acacia karroo on experimental haemonchosis was determined in 4-month-old castrated Xhosa lop-eared kids. The goats were randomly allotted into four treatment groups: non infected, non supplemented (NINS); infected, non supplemented (INS); infected, supplemented (IS) and non infected, supplemented (NIS). Each treatment group contained six goats. Each goat in the infected groups was exposed to a single dose of 6000 freshly cultured L3 Haemonchus contortus larvae. The kids in the supplemented groups received 182g/day (on DM basis) of fresh A. karroo leaves, constituting 50% of their diet. Blood samples were collected every two weeks to determine haematology and serum enzyme concentrations. At the end of the experiment at day 60, all the kids were humanely slaughtered to determine the worm burdens. A significant decrease in faecal larval counts (FLC) was observed in the IS group as infection progressed while it continually increased in the INS group after Week 4 of infection. At necropsy, the INS group had significantly (P<0.05) higher worm counts than the IS group (225.5±43.75 versus 25±43.75). Highest packed cell volume (PCV) values were observed in kids in the NIS group. The INS goats had the lowest PCV values. Mean FAMACHA scores for the IS and INS groups were higher (P<0.05) than that of the NINS. Alkaline phosphatase levels (ALP) in the INS group increased as the infection progressed. On the contrary, in all other groups, ALP levels decreased up to Week 4 post infection. Supplemented goats had a significantly (P<0.05) lower mean serum glutamic pyruvic transaminase (SGPT) and serum glutamic oxaloacetic transaminase (SGOT) values than the non-supplemented group. Results from the current study suggested that consumption of fresh A. karroo leaves reduced infection level and subsequently the leakage of enzymes into blood. It can be concluded that consumption of fresh A. karroo leaves reduced the establishment of H. contortus in Xhosa lop-eared goats.