Fibrolytic enzyme and ammonia application effects on the nutritive value, intake, and digestion kinetics of bermudagrass hay in beef cattle

Abstract

The objectives were to compare the effect of exogenous fibrolytic enzyme (Biocellulase A20) or anhydrous ammonia (4% DM) treatment on the nutritive value, voluntary intake, and digestion kinetics of bermudagrass (Cynodon dactylon cultivar Coastal) hay harvested after 2 maturities (5- and 13-wk regrowths). Six individually housed, ruminally cannulated Brangus steers (BW 325 ± 10 kg) were used in an experiment with a 6 × 6 Latin square design with a 3 (additives) × 2 (maturities) factorial arrangement of treatments. Each period consisted of 14 d of adaptation and 7, 4, 1, 1, and 4 d for measuring in vivo digestibility, in situ degradability, no measurements, rumen liquid fermentation and passage indices, and rate of solid passage, respectively. Steers were fed hay for ad libitum intake and supplemented with sugarcane molasses and distillers grain (supplement total of 2.88 kg DM/d). Enzyme did not affect the nutritional composition of hay but ammonia treatment decreased hay NDF, hemicellulose, and ADL concentrations and increased the CP concentration particularly for the mature lignified 13-wk hay. The enzyme increased NDF and hemicellulose digestibility of the 5-wk hay but decreased those of the 13-wk hay. Ammoniation decreased intake of hay but increased digestibility of DM, OM, NDF, hemicellulose, ADF, and cellulose and increased the ruminal in situ soluble and potentially digestible fractions and the rate of DM degradation of the 13-wk hay. Also, ammoniation increased the concentrations of ruminal NH3, total VFA, acetate, and butyrate but enzyme treatment did not. Neither enzyme addition nor ammoniation affected rate of liquid and solid passage. In conclusion, ammoniation decreased the concentration of most fiber fractions, decreased the intake of hays, and increased their CP concentration, in vivo digestibility, and in situ degradability at both maturities whereas enzyme application increased fiber digestibility of the 5-wk hay but decreased it in the case of the 13-wk hay.

Screening exogenous fibrolytic enzyme preparations for improved in vitro digestibility of bermudagrass haylage

“…Our study, therefore, supports the notion that effective EFE products affect the HEM fraction more than other fiber fractions in BH (Romero et al, 2013). Relative to EFE 11C, which also was very effective at increasing NDFD, EFE 2A had 14.3 times more XY III, 14.3 times more β-xylosidase, 7.7 times more EN III, and 1.9 times more polysaccharide monooxygenase, though the differences were less than those between 2A and 9C (Table 9).…”

“…Compared with the control, treatment with 6 EFE increased DMD (53.8 to 54.9 vs. 52.0%; P < 0.05), 9 increased NDFD (37.8 to 40.4 vs. 35.6%; P < 0.05), 9 increased HEMD (35.3 to 38.0 vs. 33.0%; P < 0.05), and 5 increased ADFD (41.3 to 42.7 vs. 38.7%; P < 0.05). The EFE-mediated increases in NDFD of BH agree with previous results of EFE on bermudagrass silage (Dean et al, 2005) and hay Romero et al, 2013). Enzymes seemed to be more effective at improving the digestibility of the HEM fraction than the ADF fraction.…”

Laboratory silo type and inoculation effects on nutritional composition, fermentation, and bacterial and fungal communities of oat silage

“…The fungal source of the enzymes contained in the inoculant was not disclosed (Zahiroddini et al, 2006). We hypothesize that relative immaturity of the oats used in this study (heading stage, before seed starch deposition) resulted in a NDF more susceptible to enzymatic hydrolysis, as less mature forage is more amenable to fibrolytic enzyme action (Romero et al, 2013).…”

The use of fibrolytic enzymes on the performance, metabolism and feeding behavior of feedlot cattle fed diets which differ in terms of level and source of roughage

“…Applying EFE to the diets did not alter ruminal pH as reported by others (Balci et al, 2007;Romero et al, 2013;He et al, 2015). also reported no difference on pH and total VFA concentration, but butyrate concentration was higher for barley diet supplemented with EFE and it was lower for sorghum diet supplemented with EFE.…”

“…Also, no ruminal NH3-N alteration for EFE treated diets was observed by some authors (Álvarez et al, 2009;Romero et al, 2013). He et al (2014) noticed that when dietary EFE increased ruminal NH3-N concentration decreased, and there were no differences for total VFA or molar proportions of individual VFA.…”