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oa In vitro effect of the adding of an exogenous enzyme blend (Natuzyme®) on rumen microbial fermentation and methane production of diets containing different NDF concentrations
- Source: QScience Connect, Volume 2014, Issue 1, Mar 2014, 3
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- 30 September 2013
- 05 December 2013
- 01 March 2014
Abstract
The objective of the present study was to evaluate the effect of an exogenous enzyme blend (Natuzyme®) on the fermentation responses of diets differing in neutral detergent fiber (NDF) concentrations, using a proposed gas production technique. Diets contained different ratios of alfalfa hay to wheat straw, to provide different NDF concentration, such as 320 (D1), 340 (D2) and 360 (D3) g/kg dry matter (DM). Two hundred fifty mg of milled and dried experimental diets in three runs and four replicates were weighed into a 125-ml serum bottle for an in vitro gas production trial. A solution of Natuzyme® was added 12 hours prior to the commencement of the incubation (96 h), to make a treatment of 1.68 (g/kg DM). Serum bottles containing substrates without enzyme were considered as the control. Gas production parameters at 96 h incubation were estimated and half time of gas production (t1/2) was calculated. Another gas test was run according to t1/2. All the incubations for each treatment were terminated at t1/2, then gas and methane volumes recorded. Apparent dry matter degradability (ADMD) was assessed by centrifugation and ‘ml methane per mg dry matter apparently degraded’ was calculated. Results showed that level of alfalfa hay incorporation and elevation of NDF concentration in the diets significantly increased the fractional constant rate. Enzyme supplementation significantly increased the ADMD of the diets at t1/2, whereas gas production and produced methane per mg of DM at t1/2 (MD) of the experimental diets, was decreased at t1/2. Increasing the NDF content of the diet showed a significant contribution in altering the fermentation parameters at t1/2. Enzyme addition is an appropriate way to control the methane emission and to improve the dry matter degradability in the ruminant gut.