Effect of Diet Quality and Housing on Water Statusin Sudanese Desert Sheep and Goats

Two independent experiments were carried out using Sudanese Desert sheep and goats to investigate water metabolism (totalbody water, TBW and water turnover, WTO) and internal water compartments using radioactive water (tritium), under natural grazingconditions in a semi-­desert area. The second trial was carried out on confined sheep, fed high (Lucerne) and poor quality (desert grasses)diets. The body weights, rectal temperature and water parameters were monitored in both trials and species under the Sudanese summerconditions. The grazing animal’s body weights were reduced compared to confined ones. Hyperthermia was pronounced in goats (9%)compared to sheep (6%). The goat hyperthermia was associated with high water turnover, indicating the poor heat tolerance of this speciesof high evaporative cooling. The confined animals, however, maintained their body weights and did not show signs of hyperthermia. Thepoor diet (desert grasses) was associated with reduced water intake whereas the Lucerne was associated with high water turnover and highfeed intake. The extracelluar compartment (ECV) was higher with the poor diet but was lower than the grazing group. The intracellularcompartment (ICV) was higher in the Lucerne group. The study indicated that Sudanese Desert sheep are more tolerant to high temperaturesand grazing system than goats.