THE EFFECT OF THE QUALITY OF ROUGHAGE ON THE COURSE OF TRYPANOSOMA-VIVAX INFECTION IN WEST-AFRICAN DWARF GOATS - II - METABOLIC PROFILE, PACKED CELL-VOLUME, AND PATHOLOGY OF DISEASE

Effects of trypanosome infection and feed quality on the metabolism of trypanotolerant West African Dwarf goats were measured. Goats were al lotted to either a diet of lucerne pellets (Crude protein level = 172 g/kg DM; n = 14) or a diet of chopped grass straw (Crude protein level = 68 g/kg DM; n = 15). Five animals per feed group served as controls , and the other animals were infected with Trypanosoma vivax parasites , Before and after infection, blood samples were taken weekly, and ana lyzed for packed cell volume and parasitaemia, and for serum metabolit es and hormone concentrations. Six weeks after infection, the goats we re killed and post mortem analysis was carried out to study the pathol ogy of disease. Infected animals showed reduced feed intake, increased plasma nonesterified fatty acids concentration, and decreased serum i nsulin concentration. Liver triacylglycerol concentration was increase d in all grass straw fed animals, and some infected goats fed the luce rne feed. Infection drastically reduced serum concentration of thyroxi ne and triiodothyronine. Infection caused an increased weight of the l iver and prescapular lymph nodes in animals from both feed treatments, but lymph nodes were more enlarged in infected animals fed lucerne. P athological findings were typical for T. vivax infection in goats, irr espective of feed type. Packed cell volume was reduced by infection in both feed groups to values below 20 percentage points. Serum gamma-gl obulin concentration was increased more in infected animals, fed lucer ne than those fed grass straw. It was concluded, that by maintaining a feed with a higher protein level, the nutritional status of infected West African Dwarf goats was improved. This was reflected in the serum concentrations of some metabolites and hormones, However, in general, no indications of an interaction between infection and feed type with respect to nutritional status were found. Differences in reed quality did not change the nature and severity of pathological variables, mea sured at autopsy after 6 weeks of infection. (C) 1998 Elsevier Science B.V.