EFFECTS OF POSTPARTUM TRYPANOSOMA-VIVAX INFECTION ON FEED-INTAKE, LIVEWEIGHT CHANGES, MILK-YIELD AND COMPOSITION IN WEST-AFRICAN DWARF EWESAND ASSOCIATED LAMB GROWTH-RATES

The effects of trypanosomiasis on digestible organic matter intake, mi lk yield and composition, dam liveweight changes during lactation and lamb growth rates were investigated at Ibadan, Nigeria 1991/92, using 20 West African Dwarf sheep nursing single lambs. Although digestibili ty coefficients were neither affected by infection nor by level of fee d intake, organic matter intake during early and late lactation was si gnificantly lower in infected dams. Nitrogen retained in late lactatio n was lower in infected animals due to reduced feed intake. Mean daily milk yields were not affected by the infection during early lactation ; however, during the second half of lactation, average daily milk yie lds were significantly lower in infected animals than in uninfected co ntrols. Variations in milk component concentrations between experiment al groups did not attain statistical significance throughout lactation . While control ewes on a high plane of nutrition (CH) gained 12.1 g/d ay, infected ewes (IH) and uninfected control ewes on a medium plane o f nutrition (CM) lost 45 and 5.4 g/day respectively during lactation. Liveweight gain in the lambs was not affected by infection in the dams . This study demonstrated reduction in feed intake, late lactation mil k yield and dam liveweight gain with no adverse effect on digestibilit y coefficients, milk composition, early lactation milk yield and lamb weight gain during T. vivax infection of lactating ewes.