Effect of urea-treated rice straw, mixed with faba bean straw, on nutrient digestibility, blood metabolites and performance of growing lambs

The present study aimed to use poor quality roughages, such as rice and faba bean straw, treated with or without urea, and their impacts on digestibility, rumen fermentation, some blood parameters, and growth performance of lambs. Twenty crossbred male lambs ( 1 / 4 Finland ×¾ Ossimi, 25±1.13kg live body weight) were chosen and divided into four groups. All lambs were fed rations of concentrated feed mixture at 2% of live weight with the following roughages ad libitum : URS (control group, untreated rice straw), TRS (urea-treated rice straw), FBS (faba bean straw), and TRS+FBS (mixture of TRS and FBS, 1:1). Nutrient digestibility and feeding values improved ( P 0.05) among evaluated groups except for NH 3 -N, the highest concentration ( P