Parâmetros cinéticos da fermentação ruminal “in vitro” de dietas com enzimas exógenas

• Autor(a) principal: Freiria, Lucien Bissi da
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/223
• topic: Amilolítica; Degradabilidade; Fibrolítica; Proteolítica; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA; Amylolytic; Degradability; Fibrolytic; Proteolytic

Three experiments were conducted, in Laboratório of Nutrição Animal in the Universidade Federal de Mato Grosso, to evaluate doses and combinations three exogenous enzymes (fibrolytic, amylolytic and proteolytic), on gas production, kinetic parameters and profile of fermentation using the technique of in vitro fermentation simulating feedlot and forage diet. In the experiment 1, this study evaluated the effects of three exogenous enzyme preparations (fibrolytic activity (FIB) 0, 0.6, 1.2, 1.8, and 2.4 mg/mL liquid incubated; amylolytic activity (AMZ) 0, 0.05, 0.10, 0.15, 0,20 mg/mL liquid incubated; and proteolytic activity (PRO) 0, 0.05, 0.10, 0.15 e 0.20 mg/mL) on the accumulated gas production, kinetic parameters, and fermentation profile using the technique of in vitro fermentation, using as substrate a feedlot diet. Ruminal liquid was obtained from two rumen-cannulated Santa Inês sheep which had been fed a diet with roughage:concentrate ratio of 20:80. The accumulated gas production (GP) was obtained during 96h of incubation, measured at 18 different times. After incubation, the study determined the pH, dry matter degradability (DMD, mg/g DM), organic matter in vitro digestibility (OMD, g/g DM incubated at 24h), metabolizable energy (ME, MJ/kg DM), partitioning factor (PF96, mg DMD:mL gás), gas yield (GY24, mL gas/g DMD), short chain fatty acids (SCFA, mmol/g DM) and microbial protein production (MCP, mg/g DM). For kinetic parameters, doses of FIB and AMZ reduced (P<0.05) Latency, and PG increased (P<0.05) at all times FIB and AMZ only in the early times. In the fermentation profile only the FIB increased (P<0.05) DMD, OMD, ME, GY24 and SCFA. The inclusion of PRO did not promote changes in the evaluated parameters. The inclusion of PRO did not promote improvements in the evaluated parameters. However, it is necessary additional searches to recommend the use of exogenous enzymes in feed for ruminants. In the experiment 2, to evaluate the same three increasing doses of exogenous enzymes, on the accumulated gas production, kinetic parameters, and fermentation profile using the technique of gas production in vitro in the Brachiaria brizantha cv. Marandu. After incubation determined the pH, asymptotic gas production (mL/g DM), fractional degradation rate ( h-1), lag time (h), OMD, EM, and the disappearance of the insoluble neutral detergent fiber (NDFD, mg/g DM). The levels of FIB and AMZ increase (P<0.05) the asymptotic gas production, with reductions in the fractional degradation rate and lag time. On the other hand, PRO enzyme did not change the asymptotic gas production, but there was a quadratic effect (P<0.05) for fractional degradation rate and lag time. Regarding the profile of fermentation, it was found that only the FIB dose increased (P<0.05) OMD, NDFD and ME. The inclusion of fibrolytic enzymes has the potential to optimize the use of forage in ruminant feed. However, it is necessary additional searches to recommend the use of exogenous enzymes in feed for ruminants. In the experiment 3, this study evaluated the effects eight combinations of three exogenous enzymes (fibrolytic activity (FIB) 2.4 mg/mL liquid incubated; amylolytic activity (AMZ) 0.10mg/mL liquid incubated; and proteolytic activity (PRO) 00.10mg/mL liquid incubated, with the combinations CON; FIB+AMZ+PRO; FIB+AMZ, FIB +PRO, AMZ+PRO, FIB, AMZ, PRO) on the accumulated gas production, kinetic parameters, and fermentation profile simulating feedlot diet and the forage. In diets feedlot and forage, the participation of fibrolytic enzymes promoted improvements in PG, kinetic parameters and profile of the fermentation, with or without the combination of other enzymes. Thus, the addition of fibrolytic enzymes (2.4 mg/ml incubated liquid) has the potential to optimize the use of diet as well as containment systems for use in ruminant feed fodder, so that a combination of exogenous enzymes proved intrusive for two production systems.