Alternative Feed Additive, Associated or Not with Antibiotic, in Weaned Piglets Feeding: Diarrhea Incidence, Intestinal Mucosa Morphology and Digestive Organs Weight

Phytogenic additives and acidifiers are potential substitutes for antibiotics in piglets feeding. Thus, this study evaluated an alternative feed additive (benzoic acid and the essential oils of eugenol, thymus and piperine) and colistin, in a 2 x 2 factorial arrangement, on fecal score, intestinal morphology, and relative weights of digestive organs in piglets. One hundred and eight crossbred piglets (5.3 ± 0.5 kg), 21 days old, were fed the following diets (3.40 Mcal/kg ME; 22.0% CP; and 1.45% digestible lysine): 1) control diet (CON), without inclusion of growth promoter feed additive; 2) diet with 40 ppm of colistin (COL); 3) diet with 0.3% of alternative additive (AA); 4) diet with 0.3% of alternative additive and 40 ppm of colistin (AACOL). The piglets were housed 3 per pen, with 9 replicates per diet, in a complete randomized block design based on initial BW. Fecal scores were recorded in the first 14 days of the trial, as follows: 1 – normal feces; 2 – doughy feces; and 3 – diarrheal feces. At the 14^th day of the trial, 9 animals per diet were euthanized, their digestive organs were weighed, and tissues samples from proximal duodenum and jejunum were collected to evaluate villi height and width, crypt depth, and goblet cell count. Data was analyzed by ANOVA using the GLM procedure. The alternative feed additive inclusion in piglets diets tended (P = 0.06) to increase (46%) normal feces frequency, decreased (P < 0.05) goblet cells count (104.3 vs. 118.1) in the jejunum, and decreased (P < 0.05) small intestine (4.60% vs. 4.93%) and colon (1.41% vs. 1.65%) relative weights, compared to pigs not fed with the alternative additive. The use of colistin increased (P < 0.05) villi width (356.1 μm vs. 351.4 μm), and goblet cells count in the jejunum (115.1 vs. 107.2). Alternative additive and colistin interacted (P < 0.05) for crypt depth in jejunum. Piglets fed diet COL showed lower (P < 0.05) crypt depth than animals fed diets CON and AACOL. Piglets fed diet AA presented similar (P > 0.05) crypt depth compared to animals fed diets CON and AACOL. The tendency for greater normal feces frequency, the fewer goblet cells count, and the lower relative weights of small intestine and colon of piglets fed diets containing the alternative additive, compared to pigs fed CON diet, indicate that intestinal health may have been promoted by the alternative additive.