Livestock genomic testing leader and innovator, Genetic Visions-ST™, has developed a commercially available genomic test for a newly identified Holstein recessive Bovine Lymphocyte Intestinal Retention Defect (BLIRD).
Alan Mileham, STgen™ Researcher says that news of a new recessive condition in Holstein cattle was reported in France in March of 2023 and named as Bovine Lymphocyte Intestinal Retention Defect (BLIRD). “Homozygous recessive animals have reduced growth and higher early mortality. Testing was initially only available in France, and it was several months before the details of the mutation causing BLIRD were published (Besnard F et al 2023 ‘Massive detection of cryptic recessive genetic defects in cattle mining millions of life histories*’). This showed that a mutation in the ITGB7 gene was causal for BLIRD,” Mileham states.
The mutation is known to alter cell adhesion in the intestinal tissue, resulting in defective retention of important cells to the immune system of calves. Phenotypically, BLIRD is associated with severely impaired animal health in the rearing phase, weakened immune defenses, below-average development and recurrent diarrhea (Leuenberger T et al 2024**). The pedigree analysis suggests a recessive inheritance from the common ancestor Holstein bull Elton, born in 1983.
Once details of the mutation were available, Genetic Visions-ST™ developed a stand-alone genotyping assay for BLIRD in early 2024. Animals carrying the mutation were identified from DNA sequencing data through bioinformatics by STgenetics®, and their DNA samples were used to validate the assay in July 2024.
Researchers recommend that clinically suspected BLIRD animals should be diagnosed by genetic testing. In addition, genotyping all Holstein cattle is desirable to identify carriers of the mutation.
As the pioneer in genomics, Genetic Visions-ST™ now offers a stand-alone test for BLIRD. Farmers interested in learning more about the test or arranging tests for their cattle can talk with their STgenetics® sales representative or contact the Dairy Inside Sales Team at 1-844-828-7849 or email at dairy@stgen.com.
Genetic Visions-ST™ is a division of STgen™. Located in Navasota, Texas, STgen™ is making the world greener, more sustainable and profitable. By improving herd genetics through science and technology, we believe that the best way to predict the future is to create it, while feeding the world with our passion for the beef and dairy industries. The STgen™ Integrated Approach to management combines cutting edge genetics, innovation driven programs and gender-sorted semen to aid farmers in improving cattle performance to feed the world while reducing their carbon footprint.
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*https://doi.org/10.1101/2023.09.22.558782
**https://pubmed.ncbi.nlm.nih.gov/39330956/