Nutritional and physiological effects of rapeseed meal sinapine in broiler chickens and its metabolism in the digestive tract

Research was completed to investigate the impact of dietary rapeseed meal (RSM) sinapine (SNP) on broiler chickens. The control treatment was based on a corn/soybean meal diet, as were six additional treatments which contained three levels of SNP bisulphate or semi-purified SNP in the form of an ethanol extract concentrate. The last three treatments were corn-based but soybean meal was replaced by graded levels of RSM at 15, 22.5 and 30% of the diet and thereby added SNP in its native form. SNP bisulphate and SNP ethanol extract did not affect feed intake and performance of broiler chickens. SNP bisulphate increased diet AME (apparent metabolisable energy) (P (less than) 0.01) while SNP ethanol extract increased diet AME and faecal protein digestibility (P (less than) 0.01 and 0.05 respectively) in comparison with the control diet. Dietary treatment caused minor effects on tissue measurements. All the diets containing SNP reduced the empty weight of caeca (P (less than) 0.05 or 0.01), suggesting that the hind gut might be an important metabolic site for SNP. The ileal digestibility of SNP was 35-42, 27-38 and 30-46% for SNP bisulphate, SNP ethanol extract and RSM SNP respectively, while faecal digestibility values were 68-72, 65-75 and 54-63% for the same treatment groups. A major metabolic pathway of SNP via hydrolysis into sinapic acid and choline in the digestive tract was identified