اثر متيونين محافظت شده بر عملكرد ، الگوي اسيدهاي چرب شير و بيوهيدروژناسيون شكمبه اي در گاوهاي شيري

چكيده انگليسي :

Effects of Rumen Protected Methionine on Performance Milk Fatty Acids Profile and Rumen Biohidrogenation in Diry Cows Mohammad Golkar mohamad golkar@gmail com Date of Submission 11 9 2011 Department of animal science Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors Dr Hamid Reza Rahmani hrahmani@cc iut ac ir Dr Masoud Alikhani alikhani@cc iut ac irAbstractTo evaluate effects of rumen protected methionie RPM on dairy cow performance cow s milk fatty acidsprofile and ruminal biohydrogenation of fatty acids Eight Multiparous Iranian Holstein cows with average 129 19 days in milk DIM were used in a replicated n 4 latin square design with two periods of two weeks Cowswere fed with control diet without methionine supplement or a diet supplemented with 15g day RPM MepronM per cow Performance outcome was measured at each the end of each week and samples from milk andrumen fluid were collected weekly Samples from cow s rumen fluid and milk from wk 1 and wk 2 were mixedtogether and analysed for fatty acids profile as an overall mean Milk samples were analyzed for fatty acidscomposition Rumen fluid samples were also analyzed for the concentration of rumen biohydrogenationintermediates Data on cow s performance were analyzed for each wk separately and as overall means for eachperiod Dietary methionine supplementation did not affect cows dry matter intake through wk 1 and wk 2 butcaused an increase P 0 0434 in overall dry matter intake by methionine supplementation cows Dry matterintake in wk 1 P 0 1401 and wk 2 P 0 1068 tended to increase RPM did not affect milk production milkfat content and yield as well as lactose content or yield Milk production in wk 2 P 0 0781 and overall P 0 1089 tended to increase by RPM diet Milk fat content tended to increase as overall mean P 0 1089 whilemilk fat production tended to increase at wk 2 P 0 1062 and overall P 0 0529 however RPM increasedprotein content significantly through wk 1 P 0 025 wk 2 P 0 0247 and overall period P 0 0039 and alsomilk protein yield at wk 2 P 0 0319 and overall experimental period P 0 0198 Lactose content at wk 1 P 0 1316 overall mean P 0 0529 and lactose production at wk 2 0 0797 and also as overall mean 0 0979 tended to increase for diet supplemented with RPM Energy corrected milk was increased significantlyin wk 2 P 0 0360 and overall period P 0 0443 for diet containing RPM Fat corrected milk FCM did notaffect by RPM however FCM tended to increase in wk 1 P 0 0598 wk 2 P 0 0616 and overall trail period P 0 0602 Milk short chain fatty acids in RPM supplemented cows were increased P 0 038 but mediumand long chain fatty acids were not affected by RPM supplementation diet Among individual short chain fattyacids caprylic P 0 0295 and capric P 0 0299 acids were increased significantly by supplementedmethionine diet Butyric P 0 1492 and caproic P 0 0828 acids tended to increase when RPM was addedto the diet RPM caused significant increases in Stearic P 0 0466 and linolenic acid P 0 0378 acid contentof ruminal fluid but trans 10 cis 12 conjugated linoleic acid P 0 0220 was reduced Interestingly Other c 18fatty acids were not altered significantly in rumen fluid The present findings indicate that dietarysupplementation of RPM can increase milk protein content and milk short chains fatty acids and also may alterrumen biohydrogenation process in dairy cows Keywords Rumen Protected Methionine Milk Production Milk Fat Milk Fatty AcidsComposition Rumen Biohydrogenation

گل كار، محمد

اثر متيونين محافظت شده بر عملكرد ، الگوي اسيدهاي چرب شير و بيوهيدروژناسيون شكمبه اي در گاوهاي شيري

الگوي اسيدهاي چرب شير