| Popis: |
The assessment of the prevalence of Subclinical Mastitis (SCM) in dairy farms is essential to validate the health status of the mammary gland. The aim of the study was to assess the prevalence of SCM in dual purpose livestock systems in Arauca, Colombian Orinoquia, through the analysis of the values found by the field diagnostic tests California Mastitis Test (CMT) and Electric Conductivity (EC). Milk samples were taken from the individual mammary quarters of 481 cows. The general prevalence, per affected room and the total number of rooms was determined according to the values obtained for each test using two methods of analysis. An ANOVA was performed to determine the difference between prevalence’s, a correlation analysis, and an analysis of sensitivity and specificity. The general prevalence was similar between the tests (CMT = 31.4%; EC = 29.7%) (p > 0.05). The prevalence of the total quarters was lower with EC (11.3% vs 14.2%) (p < 0.05). The correlations between tests were significant, but with low values (rs = 0.20-0.25). CMT and EC test concordance showed a sensitivity between 0.35-0.45 and a specificity of 0.75-0.90. The two tests showed positive results in detecting the same animals with or without the presence of the infection, although some animals that were positive for one test were not positive for the other test. The test EC classified animals and their quarters as SCM positive or negative in a more similar way to that obtained with CMT. The two diagnostic tests showed a general low prevalence of SCM in the livestock systems evaluated. |
