بررسي حساسيت و ويژگي CMT در تشخيص اورام پستان تحت باليني در گاو شيري

Sensitivity and specificity of CMT to detect sub clinical mastitis in dairy cows

Mastitis is one of the most costly and troublesome diseases among other diseases of dairy cows. Diagnosis of the disease in the subclinical form is very important since in such cases the qualitative as well as the quantitative value of the milk is reduced. In addition, in the sub clinical form a major art of the cowʹs udder has already been affected. Therefore, it should be diagnosed and treated as soon as possible. Among the wide variety of diagnostic tests, the California mastitis test is of special important diagnosis of the subclinical mastitis at the dairy farm. In view of the easiness with which this test is carried out, it is today widely applied as a screening test in industrial cattle farms for searching and identifying subclinical mastitis. Study of the sensitivity and specificity of CMT for diagnosis of subclinical mastitis and also how far this test matches the bacterial culture and somatic cell count was the aim of this study. In order to achieve these goals, 268 milk specimens were obtained in an absolutely hygienic manner prior to milking of the cows in sterile universal tubes for bacteriological culture and the same number in small plastic bottles to be sent for cellular count. Plastic bottles contained little potassium dichromate which protect cells found in milk up to their count time. The number of positive culture specimens was 143 for positive CMTʹs and 27 for negative CMTʹs. The number of negative specimens was 38 for positive CMTʹs and 6 for negative CMTʹs. The separated bacteria existing in the samples included E. coli,p and non-hemolytic Staphylococi, (beta)and non-haemolytic Streptococi Bacillus and Klebsiella. Based on the results obtained from SCC in comparison with +3, +2, +1 and negative CMTʹs has an SCC on average equal to 7190000, 1930000, 1240000 and 154000 respectively. As a final conclusion, sensitivity and specificity of CMT compared with culture and SCC, was 84.1 per cent and 97.5 per cent, 61.22 per cent and 79.6 per cent respectively.