کاربرد پوسته برنج به‌عنوان یک منبع فیبر نامحلول در جیره جوجه‌های گوشتی

The experiment was carried out using 200 Ross 308 broiler chickens in a completely randomized design with 5 treatment and 4 replicates. The experimental diets were consisted of a control free hulls diet and four diets containing 0.75 or 1.5 percent rice hulls with particle sizes of less than 1 mm or between 1-2 mm.  The performance traits were determined through 42 d experimental period and carcass traits were expressed as a ratio of live weight.  The digestibility coefficients of nutrients of the experimental diets were also determined. At grower phase, the diets contained 1.5% rice hulls regardless of their particle size, improved weight gain compared to the group fed the diets with 0.75% rice hulls (P<0.05). The experimental diets did not affect feed intake of broilers. The feed conversion ratio in group fed the diet contained 0.75% rice hulls with 1-2 mm particle size was lower than the group fed the diet contained 0.75% rice hulls with particle size of less than 1 mm (P<0.05). Gizzard weight in chickens fed the diet contained 1.5% rice hulls with particle size of 1-2 mm was increased and the observed difference with the group fed the diet contained 0.75% rice hulls with particle size of less than 1 mm was significant (P<0.05). The digestibility coefficients for dry matter, ash and crude fat improved in the diet contained 0.75% rice hulls with particle size of 1-2 mm and the difference with the control diet was significant (P<0.05). The results of the present study suggest that including rice hulls with 1-2 mm particle size at 0.75% of the diet could positively affect performance traits and feed cost of broiler chickens.