Open AccessPrevalence of nine genetic defects in Chinese Holstein cattle
Author(s) -
Khan Md. Yousuf Ali,
Omar Abdullah I.,
He Yuwei,
Chen Shaohu,
Zhang Shengli,
Xiao Wei,
Zhang Yi
Publication year - 2021
Publication title -
veterinary medicine and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 11
ISSN - 2053-1095
DOI - 10.1002/vms3.525
Subject(s) - haplotype , biology , genetics , allele , dairy cattle , holstein cattle , genetic variation , inbreeding , genetic marker , herd , gene , zoology , population , medicine , environmental health
Worldwide use of elite sires has caused inbreeding accumulation and high frequencies of genetic defects in dairy cattle populations. In recent years, several genetic defect genes or haplotypes have been identified in Holstein cattle. A rapid and reliable microfluidic chip with Kompetitive allele‐specific PCR (KASP) assay was developed in our previous study for the detection of heterozygotes at eight genetic defect loci of bovine leukocyte adhesion deficiency (BLAD), Brachyspina syndrome (BS), complex vertebral malformation (CVM), Holstein haplotype 1 (HH1), Holstein haplotype 3 (HH3), Holstein haplotype 4 (HH4), Holstein haplotype 5 (HH5) and haplotype for cholesterol deficiency (HCD). This study aimed to extend that assay to include a newly identified genetic defect of Holstein haplotype 6 (HH6) and to estimate the frequencies of carriers for each of the nine genetic defects in six Chinese Holstein herds. Of the 1633 cows, carrier frequencies of the genetic defects were 6.92%, 5.76%, 4.46%, 4.30%, 3.62%, 2.94%, 1.86% and 0.37% for HH1, HH3, CVM, HH5, HCD, BS, HH6 and BLAD, respectively. No carrier was found for HH4. Notably, 27.43% of cows carried at least one genetic defect, while 2.27% and 0.12% of cows carried double and triple genetic defect alleles, respectively. The existence of genetic defects calls for routine molecular testing and effective management of genetic defects by avoiding carrier‐to‐carrier mating in production herds and eliminating or at least reducing the frequency of the defective alleles through marker‐assisted selection in breeding herds.