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

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.

[1]  A. Fredeen,et al.  Effect of enzyme additives on quality of alfalfa/grass silage and dairy cow performance , 1993 .

[2]  C. W. Hunt,et al.  Effect of enzyme preparations on in situ and in vitro degradation and in vivo digestive characteristics of mature cool-season grass forage in beef steers. , 1996, Journal of animal science.

[3]  G. Varga,et al.  Rate and Extent of Neutral Detergent Fiber Degradation of Feedstuffs in Situ , 1983 .

[4]  J. Matis,et al.  Compartment models for estimating attributes of digesta flow in cattle , 1988, British Journal of Nutrition.

[5]  S. Spoelstra,et al.  The effects of ensiling whole crop maize with a multi-enzyme preparation on the chemical composition of the resulting silages. , 1992 .

[6]  P. V. Soest,et al.  Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. , 1991, Journal of dairy science.

[7]  E. Emery,et al.  Volatile Fatty Acid Analyses of Blood and Rumen Fluid by Gas Chromatography , 1961 .

[8]  M. R. Stokes.  Effects of an enzyme mixture, an inoculant, and their interaction on silage fermentation and dairy production. , 1992, Journal of dairy science.

[9]  E. Ørskov,et al.  Manipulation of rumen fluid pH and its influence on cellulolysis in sacco, dry matter degradation and the rumen microflora of sheep offered either hay or concentrate , 1983 .

[10]  L. Satter,et al.  Effect of ammonia concentration on rumen microbial protein production in vitro , 1974, British Journal of Nutrition.

[11]  W. Flatt,et al.  the Evaluation of Feeds through Digestibility Experiments , 1975 .

[12]  G. Hartnell,et al.  Extent of particulate marker (samarium, lanthanum and cerium) movement from one digesta particle to another. , 1979, Journal of animal science.

[13]  C. W. Hunt,et al.  Effect of dietary level of barley-based supplements and ruminal buffer on digestion and growth by beef cattle. , 1990, Journal of animal science.

[14]  J. Choung,et al.  The effect of the addition of cell‐wall degrading enzymes at ensiling on the response to postruminal supplementation of protein in dairy cows receiving a silage‐based diet , 1992 .

[15]  J. A. Beers,et al.  Effects of addition of cell wall degrading enzymes on the chemical composition and the in sacco degradation of grass silage , 1989 .