Sangwan, M.L.Aarti2017-08-012017-08-012014http://krishikosh.egranth.ac.in/handle/1/5810026892The present investigation was aimed to study the genetic polymorphism in DRB3 gene by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique along with nucleotide sequencing and its association with Haemonchus contortus infection. A total of 106 Beetal breed of goats were screened for FEC. 25 goats with high FEC and 25 with low FEC were selected. FEC below 500 epg was interpreted as low egg count, between 500 to 2000 as moderate egg count and greater than 2000 as high egg count. Genomic DNA was isolated from blood by phenol chloroform method. DNA quality and quantity was checked by agarose gel electrophoresis and UV spectrophotometer. When 285 bp PCR products of exon2 of DRB3 gene digested with PstI and TaqI enzyme two alleles and three genotypes were observed and 319 bp PCR product of exon 2 of DRB3 gene digested with HaeIII four alleles and eight genotypes were observed. In case of PstI and TaqI enzyme digestion, allelic frequency of b allele is more than a allele and in HaeIII digestion allelic frequency of a is more than b, c and d. Genotype dd present only in animals having high faecal egg count. By applying chi-square test, no significant association was found between the genotype generated by different restriction enzyme (PstI, TaqI and HaeIII) and animals of high and low faecal egg count. Faecal egg counts are the traditional disease indicator trait for investigation of gastrointestinal parasitic infections. Mean faecal egg count in animals in two categories was found to be 2995.83 ± 238.85 and 298 ± 30.62, respectively.enThesis