Effect of urea treatment on the nutritive value of local sorghum and millet straw: a comparative study on growing performance of Djallonke rams

Two tons of and chopped millet and sorghum straws have been treated with an urea solution at 5% (100 kg of straw, sprinkled with 50 lt. of solution). Treated straws were used as basic diet (900 g day) associated to 100 g of cotton cake for 24 growing Djallonke rams in comparison to non treated straws. Four groups of animals were fed for 98 days with: urea treated sorghum (UTSS), not treated sorghum straw (NTSS), treated millet (UTMS), non treated millet straw (NTMS). Treated straws presented an increase of NDF of about 9%, of total nitrogen from 2 to 3 times while digestibility of dry matter increased respectively by 8,8% and 23,0% respectively in treated sorghum and millet. Also dry matter intake increased by 4,5% and 15,5% for treated sorghum and millet respectively compared to non treated. Mean weekly weight gain were significantly higher (P<0.05) for UTSS e UTMS compared to NTSS e NTMS. While the weekly weight gain, did not differed between UTSS vs. UTMS and NTSS vs. NTMS. At the end of the trial the UTSS and UTMS group presented a weight gain of about 40% and 38.7%, of their initial weight; while the gain for both NTSS and NTMS was respectively of 31.1% and 29.5%.