The effects of commercial chestnut (CWE) and quebracho (QUE) extract at different inclusion levels to soybean meal (SBM) on the in vitro degradability and digestibility of dry matter (DM) and crude protein (CP) were evaluated. Samples were prepared by mixing 0 (CON), 15, 30, and 60 g/kg of CWE and QUE with SBM, soaked in water overnight at room temperature, dried, and ground. Samples were incubated in duplicate in buffered rumen fluid for 24 hr at 39°C. In vitro rumen degradability of DM and CP of tannin‐treated SBM decreased with increasing quantities of tannins, especially with CWE‐treated SBM. In vitro abomasal (pepsin‐HCl) digestibility of the DM and CP was only slightly suppressed. As a result, rumen by‐pass protein (BP‐CP) increased with increased quantities of tannins, especially with CWE‐treated SBM. In comparison with nontreated SBM, the BP‐CP digestibility did not decrease, except with the highest quantity of QUE. Treatment of the SBM with tannins, especially with CWE, increased flow of the undegraded protein to the abomasum, suggesting the better supply of the ruminant animal with amino acids.

An in vitro study was conducted to investigate the effects of soybean meal (SBM) treated with two commercially available quebracho (QUE) and chestnut wood (CWE) extracts, at three different concentrations (15, 30 and 60 g/kg SBM) on the extent and rate of gas and short-chain fatty acid (SCFA)...

The gastrointestinal tract of broilers is susceptible to oxidative stress induced by heat stress (HS) and diet, which can be mitigated by the supply of exogenous vitamins and antioxidants. The aim of this study was to compare the extent of the effects of cyclic HS, and high levels of polyunsaturated fatty acids (PUFA) (HP) on gut health. It also aimed to investigate whether additional supplementation with vitamins E, C and selenium (HA) is required to support gut health under these conditions. In the present study, 192 one-day-old male Ross 308 broilers were randomly divided into eight experimental groups. Exposure to HS and HP significantly (p < 0.001) decreased villus height and villus-to-crypt ratio in the duodenum, while no differences were observed in the jejunum and ileum. In addition, oxidative stress in the liver, indicated by increased malondialdehyde (MDA) levels, was increased in the HP groups (p < 0.0001), while the HA groups had a positive effect on lowering MDA levels. The results confirm that cyclic HS and HP induce oxidative stress that damages the structure of intestinal morphology and that supplementation with HA could be a potential approach to mitigate the negative effects of these stressors.

Optimizing dietary protein utilization is essential for improving ruminant nutrition, and tannins can reduce the ruminal degradability of soybean meal (SBM) proteins through tannin–protein complex formation, a process enhanced by water. This study evaluated three water levels (1:0.625, 1:1.25, 1:2.5 w/v) combined with chestnut or quebracho tannins at 50 and 100 g/kg on in vitro dry matter (DM) and crude protein (CP) degradability and digestibility of SBM. Increasing water levels significantly reduced crude protein degradability (p < 0.05), with the greatest decline observed for chestnut tannins at 100 g/kg, decreasing from 640 g/kg at the lowest water level to 423 g/kg at the highest. Post-ruminal crude protein digestibility increased slightly with water for this treatment (from 977 to 984 g/kg). Bypass protein content ranged from 138 g/kg (quebracho 100 g/kg, low water) to 563 g/kg (chestnut 100 g/kg, high water), with increases of 20.7% and 22.6% for chestnut tannins at 50 and 100 g/kg, respectively. Bypass protein digestibility improved by up to 4.4%. Dry-matter degradability decreased by 6.8% to 23.5% depending on treatment. These findings demonstrate that water greatly enhances tannin efficacy and highlight its potential for improving protein utilization.