Effects of Mixture of Organic Acids and Medium Chain Fatty Acids on Growth Performance, Diarrhea Incidence and Fecal Microbial Flora in Weaning Pigs Orally Challenged with Enterotoxigenic Escherichia coli K88

The experiment was conducted to evaluate the effects of mixture of organic acids (OAs) and medium chain fatty acids (MCFAs) on the growth performance, fecal microbial flora and diarrhea score in weaning pigs challenged with enterotoxigenic Escherichia coli K88. A total of 30 weaning pigs (28 ± 1 d of old, 6.24 ± 0.36 kg) were randomly divided into 1 of 3 dietary treatments on the basis of initial body weight (BW) and sex (5 replicate pens per treatment with 1 barrow and 1 gilt per pen). The dietary treatments were: (1) CON, basal diet; (2) CON + 0.2% mixture of OAs and MCFAs (MOM2); 3) CON + 0.4% mixture of OAs and MCFAs (MOM4). The mixture of OAs and MCFAs used in the experiment was provided by a commercial company (Morningbio Co., Ltd., Cheonan, South Korea). The active ingredients were 17% fumaric acid, 13% citric acid, 10% malic acid and 1.2% MCFAs (capric and caprylic acid). During d 8 to 10, pigs were orally challenged with 5 mL enterotoxigenic Escherichia coli K88 (10⁹ CFU/mL). Individual BW and feed consumption on the pen basis were recorded at the beginning, d 7, d 14 and d 21 to obtain average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F), respectively. Throughout the experiment, compared with CON treatment, MOM2 and MOM4 groups had increased (P < 0.05) ADG, ADFI and G:F with the exception of G:F during d 8 to 14. During pre- and post-challenge (d 8 to 14), the diarrhea score was lower (P < 0.05) in MOM2 (3.25 and 3.61, respectively) and MOM4 (3.25 and 3.68, respectively) treatments than that in CON (3.50 and 4.29, respectively) treatment. However, diarrhea score did not differ between dietary treatments between d 15 and 21 (P > 0.05). Fecal Escherichia coli concentration was decreased (P < 0.05) in pigs fed MOM2 (7.25 log10 CFU/g) and MOM4 (7.27 log10 CFU/g) diets when compared with those fed CON (7.42 log10 CFU/g) diet. Results indicated that dietary supplementation with the blend of OAs and MCFAs at the levels of 0.2% or 0.4% improved growth performance and reduced diarrhea as indicated by reduced diarrhea score and reduced fecal Escherichia coli in weaning piglets that orally challenged with enterotoxigenic Escherichia coli K88.