The Availability of Energy and Protein, with Respect to Uric Acid, of Yellow-seeded Rapeseed Meal in Broiler Diets

Experiments were conducted to evaluate the nutritional value of yellow-seeded rapeseed meal (YRSM). In the first experiment nutrient retention was recorded by 48 Arbor Acres-broiler chickens (28-d old) to determine AMEn (nitrogen-corrected apparent metabolizable energy), coefficient of apparent protein digestibility based on ileal digesta nitrogen, excreta nitrogen and uric acid nitrogen. The second experiment was carried out with 304 Arbor Acres-broiler chickens to compare effects of SBM (soybean meal) and YRSM on performance, carcass and digestive tract status. In the control treatment, SBM was replaced by graded levels of YRSM at 15, 22.5 and 30% of diet. Digestibility of YRSM protein was significantly lower (p<0.001) than SBM protein. The protein digestibility based on ileal measurement was significantly higher (p<0.001) than protein digestibility from excreta samples. There was no significant difference (p>0.001) between ileal and excreta digestibility of protein based on uric acid. AMEn as a fraction of gross energy was 0.54 in SBM and 0.45 in YRSM. With the exception of 30% YRSM, other YRSM treatments resulted in major effects on length and weight of the gastrointestinal tract. The results of this study have shown no adverse effect on performance as well as protein digestibility and energy value in response to replacement of SBM by YRSM with the exception of 22.5 and 30% YRSM.