study was designed to investigate prevalence of mastitis in
field condition, bacteria associated with mastitis and also
susceptibility of bacteria to various antibiotics. During
the period of two year (July, 2010 to June, 2012), total
10539 milk samples from healthy cross bred cows were tested
for mastitis from 50 different villages of Anand district of
Gujarat state covered under AMUL milk shed area and were
subjected to California Mastitis Test as a screening test.
Among found positive samples, 500 milk samples were randomly
collected in aseptic condition and cultured on media such as
Blood agar, Macconkey's agar, Staphylococcus medium no. 110
and nutrient agar. The inoculated plates were incubated
aerobically at 37 degree C for 24-48 hours. Growth of
different bacteria was yielded. The isolated organism were
identified and subjected to 8 commonly used antibiotics for
determination of antibiogram. Out of tested 10539 milk
samples from healthy cows, 4932 cows (46.80%) were found
positive for sub-clinical mastitis. From 500 positive milk
samples, 235 (47%) samples yielded bacterial growth.
Gentamicine, Enrofloxacine and Ceftriaxone were found most
effective drugs amongst the 8 antibiotics tested in vitro.
Mastitis is managemental problem and mastitis prevention
practices like dry cow therapy, pre and post-milking teat
dip are not practiced under field condition ultimately
reflects the bad quality of milk availability.