7428

6934

كارشناسي ارشد

علوم دامي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1391

سيزده، 85ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

محمدعلي ادريس، اميرحسين مهدوي

مجيد طالبي، حميدرضا رحماني

16/10/91

سعيد انصاري، امير مساح

1396/09/22

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6934

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Evaluation of Relarionship Between the TLR4 Gene with Somatic Cell Score and Prodction Traits in Holstein Dairy Cattle Razieh nuri Razi nori@yahoo com Date of submission 2012 Department of Animal Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language farsi Supervisor M A Edriss edriss@cc iut ac ir A H Mahdavi mahdavi@cc iut ac ir Abstract Because of the TLR4 polymorphism on the milk trait has been proven this study was to assess the frequency of TLR4 T4CRBR2 polymorphism in Iranian Holestein dairy cows In addition the other aim in this study was estimating the association between the TLR4 T4CRBR2 and productive trait performance of milk as well as somatic cell score of milk SCS in this population The gene toll like receptor 4 TLR4 had been mapped to the bovin BTA8 and encodes the TLR4 receptor The considered polymorphism results from C T nucleotide substitution in TLR4 gene exone 3 and so teronine to isolusine of amino acid change in product protein This polymorphism proved to significantly affect the percentage milk productin TLR4 gene was studied in this population cows by PCR RFLP technique The 382 bp fragment including the considered polymorphism was amplified and digested with enzyme ALU1 to determine the genotypes of 400 Holstein cows Both alleles A and B were detected after digested by the restrictive enzyme AA individuals have not mutant alleles AB individuals have one mutant allele and BB individuals have two mutant alleles Genetic analysis of the population was done by the software PopGen32 Frequency of genetic AA AB and BB genotypes were respectively 0 1 0 55 and 0 35 and frequency of A and B alleles were estimated 0 37 and 0 63 respectively For the statistical analysis investigation relationship between TLR4 T4CRBR2 with productive traits of milk and somatic cell score of milk in first lactations the software SAS procedure GLM was used In the analysis model the effects of genotype and combined effect of herd year and season of parturition were considered as fixed effects and days in lactitation open days and milk production were considered as covariables The statistical analysis showed significant effects of the genotype for corrected fat percentage milk breeding value protein percentage and somatic cell score of milk traits but genotypes have not significant effect for fat breeding value Estimated average effects of substituting the isoleusine for the tereonine variant on record corrected of milk production dairly milk production average fat percentage protein percentage somatic cell score of milk and on milk breeding value and fat breeding value These results can be showed that allele B is effect on increase milk production and decrease fat of milk The relatively hight frequency of the B allele than the A allele may be due to selection for milk yield in recent years Results showed that the TLR4 T4CRBR2 polymorphism can be a source that underlies the reported quantitative trait loci for fat content trait in the proximal region of bovine chromosome 8 Keywords TLR4 gene Holstein cows Genotype Polymorphism

محمدعلي ادريس، اميرحسين مهدوي

مجيد طالبي، حميدرضا رحماني

سعيد انصاري، امير مساح