Effect of organic acids and essential oils on performance, intestinal health and digestive enzyme activities of weaned pigs

This experiment was conducted to evaluate the effects of organic acid (OA) and essential oil (EO) used individually or combination on performance, fecal microbiota, intestinal morphology and digestive enzymes of weaned pigs. A total of 210 weaned piglets [Duroc x (Landrace x Yorkshire)] with initial body weight (8.64 +/- 0,33 kg) were randomly allocated to 1 of 5 treatments with 7 replicate pens (3 barrows and 3 gilts per pen) per treatment according to sex and weight in randomized complete block design. The treatments consist of NC (negative control, corn-soybean meal basal diet), PC (positive control, NC + 15 mg/kg Colistin sulfate, 2 mg/kg Nosiheptide and 50 mg/kg Olaquindox), OA (NC + 1.5 g/kg OA), EO diet (NC + 30 mg/kg EO), OA + EO diet (NC + 1.5 g/kg OA + 30 mg/kg EO). The experiment lasted 28 d (d 0-14 as for early period and d 14-28 as for later period). From d 0 to 14, EO had greater (P < 0.05) average daily gain (ADG) compared with NC, EO and OA + EO had a trend to improve ADG compared with PC. From d 14 to 28, OA improved (P < 0.05) ADG compared with NC and OA + EO had a trend to improve ADG compared with PC. From d 0 to 28, supplementation of OA or EO individually increased (P < 0.05) ADG compared with NC and OA + EO had a trend to increase ADG compared with PC. EO improved apparent digestibility of dry matter, calcium, phosphorus, crude protein and gross energy (P < 0.05). OA improved digestibility of calcium, phosphorus and crude protein (P < 0.05). Compared with NC, OA tended to decrease (P < 0.10) fecal score from d 0 to 7. OA, BO and OA + EO had greater Lactobacilli counts of feces (P < 0.05) than PC. OA and EO increased villous height of duodenum and OA increased villous height of jejunum (P < 0.05). OA increased butyric acid concentration of cecum and valeric acid concentration of colon (P < 0.05). Trypsin and chymotrypsin activities of jejunum were improved (P < 0.05) by EO supplementation. Overall, OA and EO had no interactive effects, but it improved performance by the different positive effects on intestinal health and digestive enzymes of weaned pigs.