title: Detection of bovine leukocyte antigen DRB3 alleles as candidate markers for clinical mastitis resistance in Holstein x Zebu.
abstract: Bovine leukocyte antigen DRB3 alleles from Holstein x Zebu crossbred dairy cows (n = 409) were analyzed using the PCR-RFLP technique. Exon II of DRB3 was amplified using locus-specific primers (HLO30/HLO32), followed by digestion with 3 restriction enzymes (RsaI, BstyI, and HaeIII). Forty alleles were found with frequency ranging from 0.005 to 0.139. The most frequently detected alleles of Holstein x Zebu were DRB3*16, *51, *23, *11, *8, and *1, accounting for 61.12% of the alleles in the population. Detection of candidate alleles for clinical mastitis occurrence was performed by logistic regression. It was found that percentage of Holstein fraction in crossbred cows had a nonsignificant effect (P > 0.05). However, parity had a significant effect on mastitis occurrence. In addition, DRB3*1 and *52 were the most associated with the occurrence of clinical mastitis, whereas *15, *51, and *22 were associated with resistance in crossbred populations. This is the first report of association of DRB3*15 and *51 with mastitis resistance. The association was validated by examining the candidate alleles in another commercial population. Highly susceptible (n = 43) and resistant (n = 42) groups of Holstein x Zebu cows were investigated. The result confirmed that DRB3*1 and *52 could be considered as susceptibility alleles, whereas *15, *51, and *22 could be considered as resistant alleles in Holstein x Zebu raised under tropical conditions. In addition, allele effects on 305-d milk production were estimated by BLUP. It was shown that most alleles associated with high clinical mastitis occurrence were related to increased milk yield. This study revealed that allele DRB3*10 had the greatest effect on increasing milk yield with moderate resistance to clinical mastitis, which could be used as a potential marker for selection in dairy genetic evaluation.
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Thailand. monchai@kku.ac.th
authors.forename: M
authors.initials: M
authors.lastname: Duangjinda
authors.forename: D
authors.initials: D
authors.lastname: Buayai
authors.forename: V
authors.initials: V
authors.lastname: Pattarajinda
authors.forename: Y
authors.initials: Y
authors.lastname: Phasuk
authors.forename: S
authors.initials: S
authors.lastname: Katawatin
authors.forename: T
authors.initials: T
authors.lastname: Vongpralub
authors.forename: A
authors.initials: A
authors.lastname: Chaiyotvittayakul
mesh_terms: D000818:Animals; D001483:Base Sequence; D001947:Breeding; D002417:Cattle; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers / Q000235:genetics*; D006649:Histocompatibility Antigens / Q000235:genetics*; D007113:Immunity, Innate / Q000235:genetics*; D007774:Lactation / Q000235:genetics; D008297:Male; D008414:Mastitis, Bovine / Q000175:diagnosis / Q000235:genetics*; D008892:Milk / Q000378:metabolism; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D015203:Reproducibility of Results
chemical_list: D005819:Genetic Markers; D006649:Histocompatibility Antigens