400 Barkey sheep from the West-Coastal desert had been exami ned for the gastro-intestinal parasites. Out of these one hundred animals with an average weight of 22 Kg., one year old and modere tly infected with gastro-intestinal nematodes had been selected. These animals were divided into four isolated groups, each of 25 sheep. Group A and B were given a concentrated daily ration. Group C and D were fed a maintenance daily ration. Group A and C were treated with parabendazole. Egg count, fecal culture and larval differentiation had been carried out before and after treat ment.
All animals kept on concentrated ration, either treated or un treated against the investigated nematodes, showed more or less a similar increase in their body weight. Animals fed on maintenance ration and treated recorded a significant increase in body weight more than their non-treated mates,
All infected animals kept on concentrated ration for 40 days, and without treatment revealed a significant increase in body weight, if compared with those treated and fed on maintenance ration.
The role played by nutrition in this study had been discussed in detail. As a conclusion, it could be advised that the proper tim of massive treatment of animals in Egypt against the gastrointestinal nematodes must be carried out during the summer time and not the winter time as it is adopted uptill now.