Impacto da inclusão de taninos e tratamento térmico do farelo de soja sobre sua fermentação e digestão in vitro

• Ano de defesa: 2021
• Autor(a) principal: Christmann, Christina Manfio
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; Zootecnia; UFSM; Programa de Pós-Graduação em Zootecnia; Centro de Ciências Rurais
• Palavras-chave em Português: Acacia mearnsii; Aditivo; Fermentação ruminal; Amônia; Ruminantes; Taninos; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA
• Link de acesso: http://repositorio.ufsm.br/handle/1/22661

In ruminant nutrition, the use of protein sources with low ruminal degradability is one of the ways to increase the efficiency of the use of dietary nitrogen and the supply of metabolizable protein to the animal. Among the promising strategies to reduce ruminal protein degradation of the foods usually used, are the thermal processing of food and the use of vegetable tannin extracts. This study aimed to evaluate the effect of inclusion levels of Acácia mearnsii tannin extract (SETA S/A, Estância Velha/RS) in soybean meal associated with different heat treatments on fermentation and in vitro digestion parameters. Three levels of inclusion of the tannin extract (0, 2.5 or 5.0% of dry matter) were tested in the soybean meal, three processing temperatures (environment (Control), 110°C or 120°C) and three times of heat treatment (without thermal treatment (Control), 15 or 30 minutes), in a 3×3×3 factorial design, with the moisture content of the mixture fixed at 20%. The material was incubated in vitro and the parameters analyzed were gas production and ammoniacal N concentration at 24, 36 and 48 hours of incubation. Additionally, the samples were incubated in situ for 16 hours and then the residue was subjected to in vitro hydrolysis with proteases in order to measure the ruminal degradability (DR), intestinal digestibility (DI) and total digestibility (DT) of the compounds nitrogenous. Three tests were carried out for each variable, each test being considered a replicate. There was no significant interaction between tannins and temperature for the variables. After 48 hours of in vitro fermentation, gas production was on average 2.8 and 7.0% lower by the inclusion of 2.5 and 5.0% of tannin extract, respectively. The heat treatment at 110ºC resulted in gas production 3.5% higher compared to room temperature or 120ºC, while the time of exposure to the heat treatment did not significantly affect the volume of gases. Ammonia release in the incubation medium was reduced 22% by the addition of 5% tannin extract and 8% by heat treatment at 120ºC. The heat treatment time or the treatment at 110ºC, as well as the addition of 2.5% tannin extract in soybean meal, did not affect the ammonia release in the incubation medium. The ruminal degradability of soybean meal was not affected by the addition of tannins or by the heat treatment time, but reduced 15% by the treatment at 120ºC. As for PNDR intestinal digestibility, the inclusion of tannins affected negatively, reducing it. There was no effect of time or temperature. The total N digestibility was affected only by the inclusion of tannins, decreasing it. Treatment with 5% tannin at 120ºC for 30 minutes has greater effect on reducing gas production and ammonia concentration, resulting in lower DR and minimal impact on DI and DT.