6581

6146

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1390

دوازده، 64ص.: مصور، جدول

ص.ع. به فارسي و انگليسي

سعيد انصاري مهياري، محمدعلي ادريس

محمد خوروش، بدرالدين ابراهيم سيد طباطبائي

22/1/91

احمد رياسي، محمد مهدي مجيدي

1396/10/10

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6146

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Influence of the Bovine Acyl CoA Diacylglycerol Acyltransferase 1 DGAT1 K232A Genetic Variation on Somatic Cell Score and Milk Performance Malihe Pirzad pirzad14@gmail com Date of Submission 25 10 2011 Department of Animal Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor S Ansari s ansari@cc iut ac irAbstractBecause of the DGAT1 K232A polymorphism in the diversification of milk fat has beenproven this study was to assess the frequency of DGAT1 K232A polymorphism in IranianHolstein dairy cows In addition the other aim in this study was estimating the associationbetween the DGAT1 K232A with productive trait performance of milk as well as the somaticcell score of milk SCS in this population The gene diacylglycerol acyltransferase 1 DGAT1 had been mapped to the centromeric end of the bovin BTA14 and encodes the acyl CoA diacylglycerol acyltransferase1 enzyme which catalyses the final step in triglyceride synthesis Because more than 98 percent milk fat consists of triacylglycerol so DGAT1 enzyme is a keyenzyme in milk triacylglycerol synthesis in the mammary gland The considered polymorphismresults from AA QXFOHRWLGH VXEVWLWXWLRQ LQ $7 JHQH H RQ 8 and so alanine to lysineofamino acid change at product protein This polymorphism proved to significantly affect thepercent fat in milk DGAT1 gene was studied in this population 408 cows by PCR RFLPtechnique A 411 bp fragment including the considered polymorphism was amplified anddigested with the enzyme CfrI to determine the genotypes of 408 Holstein cows Bothalleles A and K were observed in population Three types of genotype including KK KA andAA were detected after digested by the restrictive enzyme AA individuals have not mutantalleles KA individuals have one mutant allele and KK individual have two mutant alleles Frequency of genetic AA KA and KK genotypes were respectively 0 3578 0 5515 and 0 0907and frequency of K and A allels were estimated 0 37 and 0 63 respectively For the statisticalanalysis investigation relationship between DGAT1 K232A with productive traits of milk andsomatic cell score of milk in first lactations the software SAS procedure GLM was used Inthe analysis model the effects of genotype and combined effect of herd year and season ofparturition were considered as fixed effect and days in lactitation open days and milkproduction were considered as covariables The statistical analysis showed significant effects p 0 05 of the genotype for corrected milk production daily milk production average fatpercent and fat breeding value traits but genotypes haven t significant effect for protein percent milk breeding value and somatic cell score of milk Estimated average effects of substituting thelysine allele for the alanine variant on record correctted of milk production daily milkproduction average fat percent protein percent somatic cell score of milk and on milk

سعيد انصاري مهياري، محمدعلي ادريس

محمد خوروش، بدرالدين ابراهيم سيد طباطبائي

احمد رياسي، محمد مهدي مجيدي