Low incidence of bovine leukocyte adhesion deficiency (BLAD) carriers in Indian cattle and buffalo breeds.

BLAD is an autosomal recessive genetic disease that affects Holstein-Friesian (HF) cattle worldwide. It is a disease characterized by a reduced expression of the adhesion molecules on neutrophils. The disease is caused by a mutation that replaces adenine at 383 with guanine, which causes an amino acid change from aspartic acid to glycine. Blood samples and a few semen samples were collected from 1250 phenotypically normal individuals, including HF (N=377), HF crossbred (N=334), Jersey (105), other breeds of cattle (N=160) and water buffalo Bubalus bubalis (N=274) belonging to various artificial insemination stations, bull mother farms (BMFs) and embryo transfer (ET) centres across the country. PCR-RFLP was performed to detect a point mutation in CD18, surface molecules of neutrophils. The results indicate that out of 1250 cattle and buffaloes tested for BLAD, 13 HF purebreds out of 377 and 10 HF crossbreds out of 334 appear to be BLAD carriers. In the HF and HF crossbred population, the percentage of BLAD carriers was estimated as 3.23%. The condition is alarming as the mutant gene has already entered the HF crossbred cattle population and therefore, the population of HF and its crossbreds needs regular screening to avoid the risk of spreading BLAD in the breeding cattle population of India.

Factor XI deficiency in Indian Bos taurus, Bos indicus, Bos taurus x Bos indicus crossbreds and Bubalus bubalis

We investigated the occurrence of Factor XI (FXI) deficiency syndrome in the following Indian dairy animals: Bos taurus Holstein-Friesian and Jersey cattle, Bos indicus Indian cattle breeds, B. taurus x B. indicus crossbreds and the river buffalo Bubalus bubalis. Factor XI deficiency is an autosomal recessive bleeding disorder known to affect Holstein cattle worldwide. A total of 1001 dairy animals, mainly bulls, were genotyped to detect the mutation within exon 12 of the gene encoding for factor XI. Two Holstein bulls were detected as heterozygous (carrier) for FXI deficiency, giving a carrier frequency of 0.6 percent in Indian Holstein cattle. None of the other cattle or buffalo breeds was found to be a carrier for FXI. Sequence comparison between normal and heterozygous animals revealed that there is a 77 base pair insertion fragment (AT (A)29 TAAAG (A)27 GAATTATTAATTCT) within exon 12 of the FXI gene. Both sequences were submitted to the National Center for Biotechnology Information (NCBI) GenBank and assigned the accession numbers DQ438908 for normal Holstein Friesian animals and DQ438909 for heterozygous Holstein Friesian animals.

Lack of carriers of citrullinaemia and DUMPS in Indian Holstein cattle.

The present study investigated the occurrence of 2 autosomal recessive genetic diseases, bovine citrullinaemia and deficiency of uridine monophosphate synthase (DUMPS), in Indian Holstein cattle. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was performed on a group of 642 animals, mainly HF and HF crossbred cattle, to identify carriers of these diseases. None of the animals were carriers of citrullinaemia or DUMPS. It is possible that with the mounting selection pressure, the international gene pool may diminish, and consequently the risk of dissemination of inherited defects will increase. It is therefore recommended to screen breeding bulls for their breed-specific genetic diseases before they are inducted in artificial insemination programmes, to minimize the risk.