کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2420921 | 1552481 | 2007 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Influence of exogenous fibrolytic enzyme level and incubation pH on the in vitro ruminal fermentation of alfalfa stems
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کلمات کلیدی
ADFRPTDMDNDFOMDdry matter degradationFibre - الیافacid detergent fibre - الیاف پاک کننده اسیدOrganic matter degradation - تجزیه مواد ارگانیکDegradation - تنزلGas production - تولید گازreading pressure technique - روش خواندن فشارRumen - شکمبه، سیرابیneutral detergent fibre - فیبر مواد شوینده خنثیfractional rate of gas production - مقدار کسر تولید گازhemicellulose - همی سلولز
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Influence of exogenous fibrolytic enzyme level and incubation pH on the in vitro ruminal fermentation of alfalfa stems Influence of exogenous fibrolytic enzyme level and incubation pH on the in vitro ruminal fermentation of alfalfa stems](/preview/png/2420921.png)
چکیده انگلیسی
A series of in vitro experiments was carried out to examine the impact of enzyme application rate and incubation medium pH on the rate and extent of fermentation of alfalfa stems. In Experiment 1, a commercial enzyme product (Liquicell 2500, Specialty Enzyme and Biochemicals, Fresno, CA, USA) was added to alfalfa stems at six levels: 0, 0.51, 1.02, 2.55, 5.1, and 25.5 μl/g (control and L1-L5, respectively) to forage DM in a completely randomized design, with a factorial arrangement of treatments. Rate and extent of fermentation and apparent organic matter degradation (OMD) were determined in vitro, using a gas production technique. Addition of enzyme linearly increased (P<0.01) gas production for up to 12 h (68.9, 70.9, 67.6, 67.9, 71.9, and 74.9 ml/g OM for control, L1-L5, respectively) and OMD for up to 19 h incubation (0.425, 0.444, 0.433, 0.446, 0.443, and 0.451 for control, L1-L5, respectively), but no increases (P>0.05) were detected thereafter. In Experiment 2, the effect of the same enzyme as used previously (added at 0.51 μl/g forage DM, directly into the incubation medium), and buffer pH were examined using the ANKOM system, in a completely randomized design. Incubation medium pH was altered using 1 M citric acid, in order to obtain target initial pH values of 6.8 (control, no citric acid added), 6.2, 5.8, and 5.4. Actual initial pH values achieved were 6.72, 6.50, 6.20, and 5.72. Lowering the pH decreased (P<0.01) dry matter disappearance (DMD) at 18 h incubation (0.339, 0.341, 0.314, and 0.291 for 6.72, 6.50, 6.20, and 5.72, respectively), whereas enzyme addition increased (P<0.05) DMD at 24 h (0.363 versus 0.387 for control and enzyme-treated, respectively). Addition of enzyme increased (P<0.05) neutral detergent fibre (NDF), acid detergent fibre (ADF), and hemicellulose (HC) degradation at pH 6.50 (0.077 versus 0.117; 0.020 versus 0.051; 0.217 versus 0.270 for control and enzyme-treated NDF, ADF and hemicellulose degradation, respectively) and 6.72 (0.091 versus 0.134; 0.041 versus 0.079; 0.205 versus 0.261 for control and enzyme-treated NDF, ADF and HC degradation, respectively). It is concluded that the positive effects of this enzyme product were independent of the pre-treatment period, but pH influenced the responses to enzyme supplementation. Under the conditions of this experiment, exogenous fibrolytic enzymes seemed to work better at close to neutrality ruminal pH conditions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Animal Feed Science and Technology - Volume 137, Issues 1â2, 1 September 2007, Pages 150-162
Journal: Animal Feed Science and Technology - Volume 137, Issues 1â2, 1 September 2007, Pages 150-162
نویسندگان
D. Colombatto, F.L. Mould, M.K. Bhat, E. Owen,