Association between BoLA-DRB3 and somatic cell count in Holstein cattle from Argentina

Area of Science:

• Animal Genetics
• Immunology
• Veterinary Science

Background:

• Mastitis resistance in cattle is influenced by genetic factors.
• The bovine lymphocyte antigen (BoLA) complex, particularly BoLA-DRB genes, is linked to infectious disease susceptibility.
• Somatic cell count (SCC) serves as a key indicator of mastitis and udder health.

Purpose of the Study:

• To investigate the association between BoLA-DRB3 alleles and SCC in Holstein cattle.
• To identify specific BoLA-DRB3 alleles conferring resistance or susceptibility to mastitis.
• To contribute to understanding the genetic basis of mastitis in Argentinian Holstein populations.

Main Methods:

• Genotyping of BoLA-DRB3 alleles in 123 Holstein cattle from La Pampa, Argentina.
• Analysis of somatic cell counts (SCC) as a measure of mastitis resistance.
• Statistical analysis using Fisher's exact test and Woolf-Haldane odds ratio to determine associations.

Main Results:

• Significant associations were found between BoLA-DRB3.2*23 and *27 alleles and mastitis resistance/susceptibility (p < 0.05).
• Alleles BoLA-DRB3.2*20 and *25 showed a suggestive association with high SCC (p < 0.1).
• Results partially align with previous studies on Japanese Holstein cattle but show discrepancies with others, potentially due to pathogen diversity and genotyping methods.

Conclusions:

• Specific BoLA-DRB3 alleles play a role in determining mastitis resistance in Holstein cattle.
• The findings suggest potential genetic markers for selective breeding to improve mastitis resistance.
• Methodological differences, such as PCR-RFLP versus PCR-SBT, may explain variations in results across studies.