Electrophoretic study of whey proteins in Holstein cows with clinical and subclinical mastitis by Agarose gel procedure

Mastitis is one the most important economic diseases in dairy cattle industry, which causes reduction in milk production, treatment expenses, reduction in herd genetic progress and fall in quality of milk. The aim of this study was to examine the milk proteins of Holstein dairy cows with different grades of clinical and subclinical mastitis. During the sampling period, none of the cows were in late pregnancy or at early lactation and also had no parasitemia and any other inflammatory diseases. Clinical and laboratory examinations which were carried out completely revealed the cows were all healthy. They were fed on corn silage, concentrate and alfalfa. In this study, the cows were divided into five groups, each group with 25 cases. For this purpose, milk samples were collected from 125 dairy cattle of two large dairy farms in Tabriz. All the cows were in the lactation period and they were milked three times a day. The groups consist of the control group with negative California mastitis test and negative culture, 2 subclinical groups, 3 subclinical group, sub acute clinical group and acute clinical group. The results of the whey electrophoresis using Agarose gel procedure indicated significant difference in albumin levels in all groups except the 2 subclinical group compared with the control group (p