An experiment was conducted to evaluate the effects of including canola meal (CM) in diets for weaning pigs challenged with a F18 strain of E. coli on growth performance and gut health. A total of 36 individually housed weaned pigs [initial body weight (BW) = 6.22 kg] were randomly allotted to 1 of the 3 diets (12 pigs/diets). The 3 diets were corn-soybean meal (SBM)-based basal diet (control diet) and the basal diet with 0.3% zinc oxide, 0.2% chlortetracycline, and 0.2% tiamulin (antibiotic diet), or with 20% canola meal (CM diet). The diets were fed in 2 phases; Phase 1: d 0 to 7, and Phase 2: d 7 to 20. All pigs were given an oral dose of 2 × 10 9 CFU of F18 strain of E. coli on d 7. Fecal score was assessed daily throughout the trial. Dietary antibiotics increased (P < 0.05) overall ADG and ADFI compared by 48% and 47%, respectively. Dietary CM increased (P < 0.05) overall ADG and ADFI by 22% and 23%, respectively; but the ADG and ADFI values for CM-containing diet did not reach those for the antibiotics-containing diet. Dietary antibiotics reduced (P < 0.05) fecal score; however, dietary CM unaffected fecal score. Dietary antibiotics decreased (P < 0.05) liver weight per unit live BW by 16% at d 20; whereas dietary CM did not affect liver weight per unit live BW (29.2 vs. 28.6). Also, dietary antibiotics increased (P < 0.05) serum triiodothyronine and tetraiodothyronine levels for d 14; whereas dietary CM did not affect the serum level of these hormones. Dietary antibiotics reduced (P < 0.05) the number white blood cells and neutrophils by 38% and 43% at d 20, respectively; whereas dietary CM tended to reduce (P = 0.09) the number white blood cells by 19% at d 20. The number white blood cells for CM diet tended to be greater (P < 0.10) than that for antibiotics diet. The dietary antibiotics decreased (P < 0.05) the concentration of individual volatile fatty acids and hence of total volatile fatty acid in cecum by 61% at d 20; whereas dietary CM decreased (P < 0.05) cecal butyric acid concentration by 61% and tended to reduce (P < 0.10) total volatile fatty acid concentration by 30% at d 20. In conclusion, the dietary inclusion of 20% canola meal improved ADG and tended to reduce white blood cell counts. Thus, inclusion of CM in antibiotics-free corn-SBM-based diets for weaned pigs that are challenged with F18 strain of E. coli can result in their improved performance partly through a reduction of the inflammatory response.

Effects of dietary canola meal (CM) on growth performance, fecal score, and blood parameters of E. coli-challenged nursery pigs were investigated. Thirty-six pigs (initial body weight = 6.22 kg) weaned at 21 d of age were housed individually and fed 3 diets (12 replicates/diet) in randomized complete block design. The diets were corn-soybean meal-based diet without or with antibiotics (0.2% chlortetracycline and 0.2% tiamulin) or with CM (20%). The diets were fed in 2 phases; Phase 1: d 0 to 7, and Phase 2: d 7 to 21. Pigs were orally challenged with F18 strain of E. coli on d 7. Feed intake and body weight were measured on d 7, 14, and 21. Blood samples for measuring thyroid hormones were collected from each pig on d 7, 14, and 21. Blood samples for measuring white blood cells, immunoglobulins, and cytokine were collected on d 21. Fecal score was assessed daily. Dietary antibiotics increased (P < 0.05) ADG by 50%. Dietary SECM also increased (P < 0.05) ADG by 23%. Week 1 fecal score was unaffected by diet. However, during weeks 2 and 3, fecal score for diet with antibiotics was less (P < 0.05) than that for basal diet or diet with CM, which did not differ in fecal score. During weeks 1 and 2, serum tetraiodothyronine level for diet with antibiotics was less (P < 0.05) than that for basal diet or diet with CM, which did not differ in serum tetraiodothyronine level; week 3 serum tetraiodothyronine level was unaffected by diet. White blood cell count was reduced (P < 0.05) by dietary antibiotics, and tended to be reduced (P = 0.087) by dietary CM. In conclusion, dietary CM increased ADG and tended to reduce white blood cell count. Thus, dietary CM at 20% may improve the performance of pigs challenged with E. coli F18 partly by decreasing immune response.