کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2446329 | 1108445 | 2019 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
α-Amylase Activity in Rumen Fluid of Cows Producing Milk of Low and Normal Fat Content
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موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم دامی و جانورشناسی
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چکیده انگلیسی
α-Amylase activity in cell-free rumen fluid from lactating cows was measured by Phadebas amylase test. Effects of handling and storage of rumen fluid on α-amylase activity were determined. Assays of 35,000 Ã g centrifuged rumen fluid stored at â18 °C showed good reproducibility, while reproducibility of assays of samples uncentrifuged prior to freezing was poor. In frozen stored samples of rumen fluid centrifuged at 35,000 Ã g or 3,200 Ã g, α-amylase activity decreased, whereas in frozen uncentrifuged samples α-amylase activity increased with storage time. α-Amylase activity was high and showed wide variations in one cow with experimentally induced low milk fat syndrome. Enzymatic activity was correlated negatively with rumen pH and positively with total concentration of volatile fatty acids. α-Amylase activity was significantly higher in rumen fluid samples from cows with low milk fat in conventional herds compared to cows with normal milk fat in the same herds. Enzymatic activity showed negative correlation coefficients with milk fat percentage and positive with total viable counts of rumen bacteria and mole percent of rumen propionic acid in the low milk fat cows but not in the cows with normal milk fat. α-Amylase activity in cell-free rumen fluid may be a useful indicator of activity of starch-hydrolyzing rumen microorganisms.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dairy Science - Volume 63, Issue 12, December 1980, Pages 2012-2019
Journal: Journal of Dairy Science - Volume 63, Issue 12, December 1980, Pages 2012-2019
نویسندگان
Anders Engvall,