INTRODUCTION: The Brazilian pig farming is extremely expressive both in the nationally and internationally scope, since Brazil is among the five principal producers in pig meat around the world. Inside the production chain, the weaning is considered one of the critical moments due the high level of stress that the animals are subject to. The changing of the environment, separation from the mother, adaptation to the new diet and living with different animals are some of the factors that predispose the stress. Also in that phase, the intestinal epithelium and microbiota suffer a series of alterations during the adaptation to the new diet. Both factors combined results in a decline of animal immunity and, by consequence, trigger the enteric diseases, highlighting the diarrhea caused by endotoxins of E. coli, which is considered the most common in newly weaned piglets. In order to minimize the impacts of this phase, productions usually use growth promoters antibiotics, however, there are many consequences described by its indiscriminate use, such as bacterial resistance. With the intention to avoid these issues and to make productions more efficient, many alternatives have been studied, among these, there is homeopathy. OBJECIVES: Therefore, on this present study, the objective was to evaluate the impact of the homeopathic additive added to the diet of newly weaned piglets on the microbiological profile of feces and cecal contents, also, to determine the resistance profile of E. coli to antimicrobials commonly used in pig productions. MATERIALS AND METHOD: The experiment was carried out at the PUCPR Swine Research Unit with 126 piglets (barrows and females). The animals were allocated according to their initial weight and sex. There were 6 treatments, with 7 repetitions, being 3 animals per experimental unit, totalizing 21 animals per treatment. The treatments studied were: T1 – Basal diet (negative control), without addition of homeopathic and antibiotic products; T2 – Basal diet with addition of antibiotic (120 mg/kg of chlorohydroxyquinoline); T3: Basal diet with addition of Homeopathic Product (addition of 4.5 kg/ton); T4: Basal diet with addition of the Homeopathic Product (addition of 6.0 kg/ton); T5: Basal diet with addition of the Homeopathic Product (addition of 7.5 kg/ton ); T6: Basal diet with addition of the Homeopathic Product (addition of 9.0 kg/ton). RESULTS: From the collected feces samples, were evaluated the population of total enterobacteriaceae, thermotolerant enterobacteriaceae and lactic acid bacteria. To determine the biochemical identification, among the thermotolerant enterobacteriaceae, 3 colonies with morphology compatible to E. coli were isolated. Subsequently, 12 different antibiotics were used to determine the susceptibility of the identified bacterias to evaluate the presence of E. coli resistance to the antibiotics. The basal diet with addition of 4.5 kg/T of the homeopathic product was the most effective to control the enteric population on animals, however, the incidence of E. coli on the collected samples were higher than 20%. Also, it was confirmed the high resistance of E. coli to different antibiotics, especially tetracycline, ampicillin and streptomycin. FINAL CONSIDERATIONS: The homeopathic product has promising results on pig farming, aiming for better intestinal health for the animals and a decrease of bacterial resistance.
