PSIX-29 Effect of quebracho (Schinopsis balansae) extract inclusion in a high roughage diet upon in situ digestion

Abstract

Abstract The objective was to determine the effect of quebracho tannin extract (QT; Schinopsis balansae) within a roughage-based diet upon dry matter and neutral detergent fiber digestibility (DMD and NDFD, respectively). The use of natural plant secondary compounds as a feed additive in animal nutrition has been studied due to their ability to modify digestive and metabolic functions in both ruminants and non-ruminants. Condensed tannin (CT) supplementation has demonstrated potential to mitigate CH4 emissions, but this commonly corresponds with reduced ruminal fiber degradation. However, prolonged supplementation of CT in a roughage-based diet is limited within the literature. Twenty rumen cannulated animals (227 ± 19 kg) were randomly assigned to four dietary treatments (n = 4): QT at 0, 1, 2, and 3% of DM (QT0, QT1, QT2, and QT3). A maintenance-fed diet containing 88% bermudagrass hay and 12% concentrate was offered at 2.1% of shrunk body weight. Steers were adapted to the base diet for 24-d then introduced to predetermined treatments for 35 d. In situ digestibility data were collected weekly over 5 wk. Digestibility estimates were determined using 48-h in situ disappearance of DM and NDF. Data were analyzed using a random coefficients model. There was no difference in DM or NDF intake for dietary treatment (P = 0.66, and P = 0.65, respectively). However, on week 2 QT2 had lower DMD (P = 0.03) and tended to decrease NDFD (P = 0.06) compared to QT1, and QT3. In contrast, there was no observed difference (P = 0.22) in DMD, and NDFD on week 1, 3, 4, 5, and when the 5-wk data were combined. The addition of QT up to 3% DM in a roughage-based diet does not sacrifice DMD and NDFD over time, but it is not clear as to why QT2 affected DMD and NDFD.