Detection and screening of bovine leukocyte adhesion deficiency in Pakistan using molecular methods

Bovine leukocyte adhesion deficiency (BLAD) is an autosomal recessive disease. Affected animals die because of extreme susceptibility to infections caused by the lack of a membrane glycoprotein called the leukocyte integrin beta-2 subunit of CD18. The present study was planned to standardize a technique for the diagnosis of BLAD and to get an estimation of BLAD allele in the Pakistani cattle population. The study was performed on 700 animals including Holstein-Friesian (HF) (n=280), Friesian-Sahiwal (FS) (n=120) Sahiwal (n=100) cows and HF calves (n=59) from Government as well as private farms. Similarly 141 bulls of Sahiwal (n=100), HF (n=18) and FS (n=23) from the Semen Production Unit Qadirabad and Kherimorat were also sampled. The identification of normal, carrier and affected animals were made by the PCR-RFLP method. No animal was found homozygous for BLAD while 10 animals including HF calve (n=1), FS bull (n=1), HF (n=6) and FS (n=2) cows were BLAD carrier. The Hardy-Weinberg frequency of the mutant allele in HF and FS population in Pakistan was calculated to 0.01. Thus there is a need of regular screening of the bulls used for artificial insemination to avoid the risk of spreading BLAD in the cattle population of Pakistan.