Condensed Tannins in Drinking Water for Broilers and Their Effects on Intestinal Micrometry, Performance, and Fatty Acid Profile in Meat.

The study evaluated the effects of including condensed tannins (CT) from Acacia mearnsii bark in the drinking water of broilers on performance, intestinal health, and meat quality. A total of 240 male Cobb 500 chickens were distributed into three treatments: negative control (NC, without tannin), NC + 500 g/m3 of condensed tannin (CT50), and NC + 700 g/m3 of tannin (CT70), with the doses defined based on a pilot study. The experiment showed that CT50 presented better initial performance (d1-21), with greater weight gain and better productive efficiency index (PEI). But when evaluating the initial and growth phases simultaneously (d1-35), we found that birds from CT50 had better feed conversion and PEI compared to NC. When considering the total experimental period (d1-42), there was no effect of the treatment on performance. In the intestine and meat, lower levels of reactive oxygen species and lipid peroxidation were observed in CT50 and CT70 compared to NC, combined with higher levels of non-protein thiols. The CT70 treatment favored meat quality, reducing saturated fatty acids and increasing the concentration of unsaturated fatty acids, ω6, and the UFA/SFA ratio. There were no significant changes in the depth of the intestinal crypts, but the greater height of villi and number of enterocytes in the groups that consumed tannins are indicative of improved intestinal health. The thickness of the intestinal wall was lower in the chickens that consumed the condensed tannin compared to the NC. Lower concentrations of total proteins, albumin, and globulin in the serum were observed in the CT70 when compared to the NC. It is concluded that the use of tannins in the drinking water can be a viable strategy to improve the performance in the initial phase (d1-21) and meat quality of chickens.