Effect of direct-fed fibrolytic enzymes on the digestive characteristics of a forage-based diet fed to beef steers.

Abstract

A study was conducted to examine the method of delivery of a solution containing cellulases and xylanases on the digestion of a forage-based diet. Five ruminally cannulated beef steers (536 kg BW) were randomly assigned to a control (CON) or one of four enzyme treatments in a 5 x 5 Latin square experiment. Steers were fed a 70:30 (DM basis) grass hay:barley diet. Enzyme-treated rations contained a solution of fibrolytic enzymes at the rate of 1.65 mL/kg of forage DM. Enzyme application treatments were 1) enzyme to forage 24 h before feeding (F-24), 2) enzyme to forage 0 h before feeding (F-0), 3) enzyme to barley 0 h before feeding (B-0), and 4) enzyme infused ruminally 2 h after feeding (RI). Dry matter and NDF intakes were not different (P > .10) across treatments. Ruminal pH was lower and total VFA concentration at 16 h after-feeding was greater (P < .10) for steers fed enzyme treatments compared with CON. Rate of NDF disappearance was greater (P < .05) for enzyme-treated than for untreated grass substrate. Ruminal infusion of enzymes compared with F-24 and F-0 produced lower disappearance of DM at 8 and 32 h (P < .10), NDF at 32 h (P < .10), and DM and NDF at 96 h (P < .05). Rate of DM disappearance of enzyme-treated grass hay was greater (P < .10) for steers fed B-0 than for those fed F-24 and F-0 and for CON than for F-24 and F-0. Total tract digestibility of DM, NDF, and ADF was greater (P < .10) for F-24 and F-0 than for CON. Forage transit time was shorter (P < .10) for B-0 than for F-24 and F-0; however, all other contrasts for particulate passage did not differ (P > .10). Results from this study indicate that direct application of enzymes to forages is capable of improving forage digestion.

Digestibilidad in situ de dietas con harina de nopal deshidratado conteniendo un preparado de enzimas fibrolíticas exógenas

“…En la literatura, se menciona que la actividad enzimática y la digestibilidad dependen del tipo y origen de la propia enzima, del sustrato en que actúe (Nsereko et al, 2000;Ramírez Cancino et al, 2005), y del pH, reportándose que la máxima actividad de xilanasas y celulasas se observa a un pH de 6 a 6,5 , aunque pH bajos pueden no afectar su actividad (Rode et al, 1999), y la digestibilidad puede ser reflejo del sinergismo entre las enzimas exógenas y los tipos de microorganismos ruminales presentes Ramírez Cancino et al, 2005). Cuadro 1.…”

“…Otros autores han encontrado que la adición de enzimas fibrolíticas, en diferentes forrajes, tiene un efecto similar al observado en el presente estudio, al elevarse la concentración total de AGV, sin embargo, la concentración de AGV solo es una medida que indica el balance entre producción y absorción de los mismos (Lewis et al, 1996;Pinos-Rodríguez et al, 2002a); asimismo se ha reportado que la concentración de N-NH 3 , en forrajes adicionados con Fibrozyme, se mantiene constante hasta por 24 horas (Pinos-Rodríguez et al, 2002b).…”

“…Las enzimas fibrolíticas exógenas pueden ser empleadas como aditivos en la alimentación de los rumiantes, ya que se ha observado que pueden mejorar la digestibilidad de las dietas, particularmente en la degradabilidad de la materia seca y de las paredes celulares de diferentes forrajes (Beauchemin et al, 1995;Feng et al, 1996;Lewis et al, 1996).…”

Influence of fibrolytic enzymes on growth performance and digestion in steers grazing stargrass and supplemented with fermented sugarcane

“…There is evidence (Dean et al 2005;Krueger and Adesogan 2008) that fibrolytic enzymes enhance forestomach digestion and fermentation of fiber in tropical grasses. The improvement of cell wall digestion by enzymes could explain the increment of DMI (Lewis et al 1996) and then enhance growth performance traits.…”

Cinética ruminal da degradação de nutrientes da silagem de milho em ambiente ruminal inoculado com diferentes aditivos

“…A utilização destes suplementos microbianos dietéticos promove melhoria no desempenho produtivo, possivelmente em razão de seus efeitos nos processos digestivos, da degradação da parede celular, da manutenção de níveis adequados de amônia no rúmen e da estabilização do pH ruminal (Huhtanen & Khalili, 1991;Yoon & Stern, 1995;Doreau & Jouany, 1998). Supõe-se ainda que a manipulação de enzimas fibrolíticas aumente a taxa e a extensão da digestão de forragem pelos ruminantes (Forsberg, 1995;Lewis et al, 1996).…”