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Influence of tannins extract addition on in vitro gas production of feces from beef cattle
Feces of fifteen bulls 392 ± 5.1 kg (75% Brahman breed with remainder of Brown Swiss or Charolais) fed finishing diets were used an experiment to determine the influence of tannins extract addition on in vitro gas production of feces from beef cattle. From each of three commercial feedlot pens containing 72 bulls, five bulls were randomly selected and moved to squeeze and fecal samples were taken. Feces of five bulls from a common pen were pooled and constitute the experimental unit. Pooled fecal sample were divides in three portions of proximately 200 g (wet basis), one portion was used for DM determination, and two remainder fecal samples by pen were randomly assigned to one of two treatments: 1) Feces without extra addition (Control); 2) Control plus addition of 2 g of a tannins extract/100 g of wet feces (TE). Tannins extract were proportioned as SilvaFeed Bypro® (SilvaTeam, Argentina), a premix integrated mainly for condensed tannin from quebracho tree blended with a minor proportion of hydrolysable tannins from chestnut. Aloquots of 50 g (wet basis) were placed in 600 mL flask (three by treatment), closed and connected with a plastic pipe to a 250 ml glass graduate probet inverted in a water bath. Flask were incubated at 37 °C during 24 and gas production was accounted as the amount of water displaced by gas inside of each probet, and was expressed as mL of gas by g of feces DM basis. This procedure was repeated during four consecutive days. Results were analyzed by ANOVA for a complete randomized block design where day run constitutes the block. Fecal dry mater content was 26.9% and dose of tannin extract was equivalent to 7.45% DM basis. The addition tannins extract diminished (P < 0.001) in 45% the in vitro gas production respect to Control treatment (8.92 vs. 16.24 mL/g of feces DM). It is concluded, that tannin extract addition could contributes to decreases gas production of feces from finishing beef cattle.
Keywords: Feces, Gas production, Tannins