Digestibilidade de grãos de canola tratados em autoclave e/ou com tanino condensado

Summary Background: plant proteins are susceptible to rapid degradation in the rumen therefore it is important to explore the best way to improve protein utilization. Objective: to evaluate the effect of heat treatment and/ or condensed tannins on ruminal degradability and in vitro digestibility of crude protein (CP) and dry matter (DM) of canola seeds. Methods: in situ and in vitro DM and CP digestibility of canola seeds treated with water (control; CCL), heat in autoclave (CLE), condensed tannin (CTN), and condensed tannin followed by autoclaving (CTA) were evaluated. Results: the DM effective degradability values (EDDM) by CCL, CLE, CTN, and CTA were 66.8%, 73.6%, 58.5%, and 77.5%, respectively. Effective degradability of crude protein (EDCP) by CCL, CLE, CTN, and CTA at a 5%/h passage rate (k) was 75.2, 77.2, 60.2, and 80.5%, respectively. Addition of condensed tannin and/or autoclaving reduced both DM and CP digestibility. Conclusions: treatment with condensed tannins protected canola seeds DM and CP from ruminal degradability, while treatment with heat or tannins combined with heat showed the opposite effect, increasing degradability of those fractions. Addition of condensed tannins and/or autoclaving decreased in vitro DM and CP digestibility.