کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8491882 | 1552406 | 2013 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Methionine analogues HMB and HMBi increase the abundance of cellulolytic bacterial representatives in the rumen of cattle with no direct effects on fibre degradation
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کلمات کلیدی
qPCRHmbVFAsCMCaseNDFaNDFomVolatile fatty acids - اسیدهای چرب فرارFibre degradation - تخریب فیبرRuminal fermentation - تخمیر شفافneutral detergent fibre - فیبر مواد شوینده خنثیneutral detergent fibre expressed exclusive of residual ash - فیبر مواد شوینده خنثی بیانگر انحصار خاکستر باقی مانده استorganic matter - ماده آلیdry matter - ماده خشکMethionine - متیونینMET - ملاقات کردbody weight - وزن بدنcrude protein - پروتئین خامCarboxymethylcellulase - کربوکسی متیل سلولاز
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Supplementation of diets for ruminants with methionine analogues such as 2-hydroxy-4-(methylthio) butanoic acid (HMB) and its isopropyl ester (HMBi) positively affect milk composition and yield, potentially partly through ruminal actions. Our objective was to investigate effects of HMB and HMBi on the rumen microbial ecosystem, with special emphasis on fibrolytic activities and fibrolytic microorganisms. Six ruminally cannulated Holstein dry cows were randomly assigned to three treatments in a 3 Ã 3 Latin square design with two cows per cell. Cows were fed twice a day at 7.5 kg/d dry matter (DM) intake with a control diet based on hay and wheat (50/50 on a DM basis) supplemented or not with HMB (Rhodimet® AT88, Adisseo at 1.25 g/kg DM intake) or HMBi (MetaSmartâ¢, Adisseo, at 2.50 g/kg DM intake). Substrate degradability (i.e., corn grain, corn silage) was evaluated by in sacco incubation and effective degradability measurements of DM, crude protein, starch and neutral detergent fibre. Fermentation products (i.e., volatile fatty acids (VFAs), ammonia, lactate) and fibrolytic enzyme activities (i.e., carboxymethylcellulase (CMCase), xylanase) were analyzed in rumen content samples before (â1 h) and after (+3 h) feeding. Protozoal populations were counted by microscopy. Abundances in total and fibrolytic bacteria Fibrobacter succinogenes, Ruminococcus flavefaciens and Ruminococcus albus in total rumen contents or adhering to in sacco residues were estimated using quantitative polymerase-chain reaction (qPCR). HMB and HMBi supplementation increased VFA concentrations in the rumen as well as the ruminal abundance of F. succinogenes (P=0.03) and R. flavefaciens (P=0.05), although these increases had no effect on the CMCase and xylanase activities of the rumen contents, nor on in sacco bacterial colonization and degradation of the two corn substrates. Under our experimental conditions, Met analogues enhanced growth of two cellulolytic bacterial representatives, but did not improve rumen fibrolytic activity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Animal Feed Science and Technology - Volume 182, Issues 1â4, 12 June 2013, Pages 16-24
Journal: Animal Feed Science and Technology - Volume 182, Issues 1â4, 12 June 2013, Pages 16-24
نویسندگان
C. Martin, C. Mirande, D.P. Morgavi, E. Forano, E. Devillard, P. Mosoni,