Vol. 11, Special Issue 10 (2022)

Author(s):
Shivashanker, R Nagaraja, Siddaling Swamy Hiremath, Shrikrishna Isloor, Shankrappa Bajantri and Yogesh

Abstract:
The present study was conducted to determine the polymorphism of TLR-4 gene and its association with mastitis in Deoni and HF crossbred cattle. Milk and blood samples were collected from 244 animals comprising of 152 HF crossbred and 92 Deoni cows. The milk samples were screened for subclinical mastitis using three indirect diagnostic tests viz., California Mastitis Test (CMT), Electrical Conductivity (EC) and Somatic Cell Count (SCC). However, the animals were classified into mastitis free and mastitis affected groups based on SCC alone because of its higher sensitivity and specificity. Miller’s high salt method was followed to isolate genomic DNA from venous blood. The quantity and quality of DNA was ascertained by spectrophotometer and 0.8 per cent agarose gel electrophoresis. A promoter region and exon 3 region of TLR-4 gene was amplified by PCR using published primers. On PCR-RFLP analysis, genetic variability was observed in TLR4 (promoter) and TLR4 (exon 3) genes in HF crossbred and Deoni cows. The TLR4 (promoter and exon 3) gene variants were not significantly associated with mastitis in both HF crossbred and Deoni cattle populations.