PSVIII-8 - Physiological response of broiler chickens fed cold-pressed canola cake-based diets with soluble fiber source or feed additives

Abstract: Effects of soluble fiber source or feed additive supplementation in cold-pressed canola cake (CPCC) containing diets on growth performance, organ weights, and blood thyroid hormones, and pH of digesta of broilers were investigated. A total of 96 one-day-old broilers were assigned to 6 dietary treatments, consisting of 8 cages of 2 birds each. The diets included a corn-soybean meal (SBM)-based diet and corn-SBM-CPCC 20% diets without or with barley, acidifier, encapsulated butyric acid, and probiotics. Birds were fed a commercial diet for the first week and fed experimental diets for 2 weeks. Body weight (BW) and feed intake of broilers were measured on days 7 and 21. On day 21, all birds were euthanized to collect samples of blood, organs, and digesta. Collected blood samples were analyzed for serum concentrations of triiodothyronine (T3) and tetraiodothyronine (T4), and pH of digesta in gizzard, ileum, ceca, and large intestine was measured. Broilers fed CPCC diet with butyric acid or probiotics had greater (P < 0.05) growth performance than broilers fed CPCC diet. There were no significant differences in relative weights of thyroid glands and liver to BW. Supplementation of either butyric acid or probiotics in CPCC diets reduced (P < 0.05) serum T3 concentration compared to CPCC diet by 34% and 21%, respectively. Also, supplementation of butyric acid in CPCC diet showed no difference in serum T3 concentration compared to corn-SBM diet. Dietary treatments in CPCC diets did not affect pH of digesta in gizzard and ileum, whereas supplementation of barley or acidifier decreased pH of cecal digesta compared to that of broilers fed CPCC diet by 0.5 and 0.51 pH units, respectively. Supplementation of encapsulated butyric acid in the 20% CPCC diet can improve growth performance of broilers by mitigating the toxic effects of dietary CPCC as evidenced by reduced serum T3 concentration.