Epidemiology of subclinical mastitis of the dairy cow in the department of Chiquimula, Guatemala

Abstract

Non-experimental research using probabilistic convenience sampling and cross-sectional observational descriptive study to determine the prevalence of subclinical bovine mastitis (MSC) of the department of Chiquimula through the California Test Mastitis Test (CMT), establishing the rates of subclinical mastitis (IMSC) ) and low risk / high risk according to the degree of infection (IBR / IAR); there is no information on the prevalence, isolation and identification of bacteria causing the MSC. The sampled population consisted of dairy production units with more than 25 liters / milk / day (n = 93), a stratified random sample consisting of 11 municipalities with a confidence level of 90%. Measured variables were liters of milk / cow, liters of milk lost by the MSC, mammary rooms with MSC, healthy, non-functional; prevalence of MSC / CMT, prevalence of bacteria (etiological agents) and,
the productive situation, risk of exposure and prediction of cases. The results in 965 cows sampled were 3,827 functional rooms, 33 non-functional rooms; 678 positive to the CMT (81.53%) with some degree of affection, the fourth previous right was the one with the highest prevalence (24.34%), of the cows with MSC there were approximately 201.5 liters / milk / day not produced, only 7.53% of the producers performs the CMT test. The bacteria isolated in milks with some degree of affection were Staphylococcus and Streptococcus (70.79%) and Enterobacteria (29.21%) according to the Microscan 2016® strain. The prevalence of MSC was 40.48%, the IMSC has a low magnitude (0.23) and the IBR / IAR are low (8.23), which indicates a high risk that the affected cow with MSC suffers from clinical mastitis.