Nutritional, physiological and metabolic effects of rapeseed meal simple phenolics in broiler chicken

Sinapine (SNP) and sinapic acid (SA) are the predominant simple phenolic compounds found in rapeseed meal (RSM). Comprehensive studies were conducted to delineate the effects of feeding these compounds to broiler chickens and to study their metabolism in vivo. Purified SNP was extracted and isolated from RSM and its identification and purity established using mass spectrometry. Purified SA (98%) was obtained from a commercial source.; Broiler chicks (n = 120) were assigned to diets containing graded levels of SNP (0.150, 0.225, 0.300%) in purified (SNP bisulfate trihydrate), semi-purified (ethanol extract) or native (rapeseed meal) forms and compared to a corn-soybean meal based control diet. SNP form or level did not affect feed intake and other performance characteristics from 0 to 18 d of age. Diet AME responded in a quadratic manner to increasing levels of purified and semi-purified SNP. A similar response was seen for fecal protein digestibility for the semi-purified SNP. Dietary treatment had minor effects on proportional tissue and digestive tract measurements but all diets containing SNP had lower empty cecal weights and feeding RSM resulted in larger livers. Ileal and fecal SNP digestibility ranged from 27 to 46% and 54 to 75% respectively. The results indicate that SNP at levels approximating those found in diets containing up to 30% RSM did not have toxic or anti-nutritional effects in broiler chickens.; Purified SA was added to a corn-soybean meal based diet at levels of 0, 0.05, 0.10, 0.15 and 0.20 and 0, 0.025, 0.050 and 0.100% in two experiments, and fed to broiler chicks from 0 to 18 d of age. In general, dietary SA did not affect performance characteristics or the size of internal organs and digestive tracts. An exception was that the 0.025% SA level in the second experiment increased feed intake and growth rate. Treatment did not affect serum creatine kinase or lactate dehydrogenase activity. Regression analysis indicated a nearly significant linear increase in AME and decrease in ileal protein digestibility with increasing SA level. Dietary SA digestibility was above 97% in the ileum and ranged from 64 to 79% in feces. The data demonstrated that the dietary levels of SA used in this experiment did not cause apparent anti-nutritional effects in broiler chickens and may cause beneficial effects at low levels of inclusion.; The bacterial profile of the ileum and ceca was assessed in all three of the above experiments by measuring volatile fatty acid (VFA) content. Both SNP and SA increased VFA production in the ileum. In contrast, cecal VFA content was not affected by dietary SNP and was dramatically reduced by SA. Further microbial analysis by percentage-guanine-plus-cytosine disclosed that dietary SA may cause a shift in the populations of cecal bacteria without changing the total number of cecal bacteria. The data indicate that RSM simple phenolics affect gut microbial ecology and that SA has antibacterial activity in vivo. (Abstract shortened by UMI.)...