Abstract:
Subclinical mastitis (SM) is a non-symptomatic form of intramammary inflammation in
the udder or teat, that affects 20–50% of cows in given herds. The majority of mastitis is
of bacterial origin, accounting for more than 90% of all mastitis diagnosis. This study was
conducted from 1st of October 2020 to 31st of April 2021. The objective of this study
was to determine the prevalence of sub clinical mastitis in semi intensively managed cattle
farms in Randomly selected Government Veterinary Ranges namely Damana,
Ampara,Samanthurei, Navithanveli, Kalmunei and Irakkamam in Ampara District. A
total of 24 farms were visited,236 milk samples were collected from all active four
quarters from 60 clinically healthy cows on which California Mastitis Test (CMT) was
performed. The results revealed that 47 quarters (47/236, 20%) were positive for CMT &
189 quarters were Negative. The prevalence of subclinical mastitis of cow level
41.6%(25/60), farm level 58.3%( 14/24) and quarter level 20%(47/236) were observed in
this study. Further, 58% (35/60) cow level),41.66(10/24) farm level and 80% (189/236)
quarter level was negative for the CMT test.These findings have demonstrated high
prevalence rate of sub clinical mastitis in cows in the selected areas.Relatively higher
prevalence may be due to improper mastitis prevention and control programs adopted by
farmers.
Further, the severity of the subclinical mastitis was graded as CMT 1+ being the most
severe to CMT 3+ being the least severe. Accordingly, most sub clinically positive
quarters had CMT 2+ readings 46.8% (22/47) while CMT 1+ reading 21.27%(10/47),
CMT 3+ reading 23.4% (11/47) and trace 8.5%( 4//47)was less. And also in cows with
3rd parity showing 13.33% high prevalence of sub clinical mastitis from 25 total positive
animals.Improper hygienic practices such as washing hands and udder, cleanness of cattle
shed and surround environment, pre and post teat dipping and unawarnes may be the
major causes for this kind of situation. Farmers should be educated on enormous
economic losses occured due to sub clinical mastitis because nearly three times as that of
clinical form and must be directed to a sound mastitis prevention and control program in
every farm in this area. In this study, Subclinical mastitis negative farms and animals
already followed standard mastitis control programme under direct supervision of
Veterinary Investigation Center,Ampara using free issue CMT reagent teat dip
solutions,proper dry cow Therapy and udder infusions according to the culture & ABST
results.
