Authors: MONA MOHAMED MOHAMED YASSEEN ELGHANDOUR, AHMED EID KHOLIF, OFELIA MÁRQUEZ-MOLINA, JOSÉ FERNANDO VÁZQUEZ-ARMIJO, ANIL KUMAR PUNIYA, ABDELFATTAH ZEIDAN MOHAMED SALEM
Abstract: This study assessed the effects of cellulase, xylanase, and their mixture (1:1, v/v) on in vitro rumen fermentation of five mixed rations with different maize silage (F) to concentrate (C) ratios (0F:100C, 25F:75C, 50F:50C, 75F:25C, 100F:0C). Samples were incubated using rumen inoculum from Brown Swiss cows fed ad libitum a total mixed ration of concentrate and alfalfa hay (1:1). Gas production (GP) was recorded after 2, 4, 6, 8, 10, 12, 24, 36, 48, and 72 h of incubation. Interaction effects (P < 0.0001) were observed between type of ration and enzyme for discrete lag time prior to GP. Ration type affected asymptotic GP (linear and quadratic, P < 0.0001) and in vitro GP at 24 h onward. Moreover, rations affected pH (linear and quadratic, P < 0.0001), dry matter degradability (quadratic, P = 0.05), metabolizable energy (linear, P = 0.038), short-chain fatty acids (linear, P = 0.0005), gas yield from truly digested dry matter at 24 h (linear, P = 0.0026), and microbial crude protein yield (linear, P = 0.0264). The most effective rations for in vitro GP during different times differed between different measured parameters. Enzyme administration was more effective when the ratio of maize silage was increased.
Keywords: Cellulase, fibrolytic enzymes, maize silage:concentrate ratio, xylanase
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