Do fibrolytic, proteolytic and amylolytic enzymes influence the in vitro fermentation characteristics of forage?

Abstract

The effects of increasing doses of three exogenous enzymes preparations with fibrolytic activity (FIB -0, 0.6, 1.2, 1.8, and 2.4 mg mL -1 liquid volume incubated), amylolytic activity (AMZ -0, 0.05, 0.10, 0.15, and 0.20 mg mL -1 liquid volume incubated), and proteolytic activity (PRO -0, 0.05, 0.10, 0.15, and 0.20 mg mL -1 liquid volume incubated ) on gas production (GP), kinetic parameters, and fermentation profile of Brachiaria brizantha cv. Marandu were evaluated using the in vitro gas production technique. Ruminal liquid was obtained from two rumen-cannulated Santa Inês sheep maintained on pasture. Accumulated gas production was measured during 96 hours of incubation, measured at 18 different time points. The determined parameters were pH, asymptotic gas production (mL g -1 ), rate of gas production (h -1 ), lag time (h), organic matter digestibility (OMD, g g -1 DM), metabolizable energy (ME, MJ kg -1 DM), and neutral detergent fiber digestibility (NDFD, mg g -1 DM). Increasing the FIB dose linearly increased (P < 0.05) the asymptotic gas production. However, the rate of gas production and the lag time showed linear decreases (P < 0.05). Addition of FIB also linearly increased (P < 0.05) the GP at all incubation times, as well as the OMD, NDFD and ME. Addition of AMZ linearly increased (P < 0.05) the asymptotic gas production, but GP linear increased (P < 0.05) only at the 6-hour and 12-hour time points. The rate of gas production and the lag time decreased linearly (P < 0.05) in response to increasing AMZ addition. Inclusion of PRO did not affect (P > 0.05) asymptotic gas production, but there was quadratic effect (P < 0.05) on the rate of gas production, the lag time, and the GP at the 6-hour and 12-hour time points. The OMD, NDFD and ME were not affected by PRO addition. Thus, fibrolytic, amylolytic and proteolytic enzymes are effective in reducing the lag time and increasing the in vitro gas production from Brachiaria Brizantha cv. Marandu forage, and fibrolytic enzymes improve the in vitro fermentation profile. Key words: Digestibility. Gas production. Rumen liquor. ResumoAvaliou-se os efeitos de doses crescentes de três enzimas exógenas: fibrolíticas (FIB), 0; 0,6; 1,2; 1,8 e 2,4 mg mL -1 volume de líquido incubado; amilolíticas (AMZ), 0; 0,05; 0,10; 0,15 e 0,20 mg mL -1 volume de líquido incubado, proteolíticas (PRO), 0; 0,05; 0,10; 0,15 e 0,20 mg mL -1 volume de líquido incubado, sobre a produção de gases (PG), parâmetros cinéticos e perfil da fermentação da Brachiaria brizantha cv. Marandu usando a técnica in vitro de produção de gases. O líquido ruminal foi obtido de dois ovinos Santa Inês canulados no rúmen, mantidos em regime de pastejo. A produção de gases acumulada foi obtida durante 96h00 de incubação, mensurada em 18 tempos. Ao final da incubação foram determinados o pH, produção de gás assintótica (mL g -1 ), taxa de degradação fracional (h -1 ), lag time (h), digestibilidade da matéria orgânica (DMO, g/g MS incubada por 24h00), energia metabolizável (EM, MJ kg -1 MS) e a digestibi...

Exogenous enzymes in sheep diet: nutritional and physiological parameters

“…The highest intake of dry matter was found for treatments with inclusion of Amaize ® (amylolytic) and Fibrozyme ® (fibrolytic) compared to diets without enzymes or with an enzyme complex. This is because, according to Freiria et al (2018), by providing fibrolytic and amylolytic enzymes separately, these in the ruminal environment have the ability to provide a higher energy content to microorganisms, promoting an increase in the number, for example, of fibrolytic and non-fibrolytic bacteria, and thus increasing the colonization and digestion capacity of fiber (e.g. cellulose) and non-fiber (e.g.…”