Revista Colombiana de Ciencias Pecuarias (Dec 2007)
Relación entre el recuento de células somáticas individual o en tanque de leche y la prueba CMT en dos fincas lecheras del departamento de Antioquia (Colombia) Relationship between individual and bull tank somatic cell counts with CMT test in two dairy herds in Antioquia (Colombia)
Abstract
El objetivo del presente proyecto fue establecer relaciones entre la prueba de CMT y los recuentos de células somáticas individuales o en el tanque de la leche, con el objetivo de definir un modelo predictivo del número de células somáticas en el tanque y proponer un modelo para detectar fincas con mastitis subclínica. En dos fincas lecheras del Municipio de San Pedro de los Milagros (Colombia), se tomaron muestras de leche de las vacas en ordeño (n = 95) durante los ordeños de la mañana y de la tarde (una muestra/mes/3 meses). En el ordeño de la tarde se realizó prueba de CMT y en todos los muestreos se hizo recuento de células somáticas en el medidor individual (RCS), y en el tanque de la leche, usando un equipo Fossomatic 90. Para el análisis estadístico se realizó una transformación logarítmica de los datos (y = Log2(RCS/100) +3), para ajustarlos a la normalidad y realizar análisis de varianza. Los resultados mostraron una relación estadística significativa (pIn order to establish a mathematical model with which to predict the Bull Tank Somatic Cell Count (BTSCC) of herds with sub clinical mastitis and to search for possible relationships between CMT results and individual somatic cell counts (SCC) or BTSCC, a descriptive study was carried out in two farms located in the dairy region of Antioquia (Colombia), in which lactating dairy cows (n = 95) were sampled during the morning and afternoon milking (once a month/3 months). CMT evaluation was performed at the afternoon milking at each time point of evaluation. In addition, total milk produced by individual cows was recorded and a milk sample was taken to perform SCC. Similarly, three samples of milk were taken from the tank to measure BTSCC. All milk samples were processed by triplicates by using a Fossomatic-90 equipment. Logarithmic transformation of data were done to normalize the SCC and BTSCC results according to the model: logarithmic SCC (SCCL) = Log2(SCC/100) +3, and analysis of variance were performed. A significant relationship (p<0.05) was found between the percent of positive quarters (at least one cross by CMT) and the BTSCC taken at the afternoon milking. Accordingly, a model was established to define the BTSCC value depending on the percentage of CMT positive quarters. The average SCC of 206.630 and 145.935 cel/ml, were found for afternoon and morning milking, respectively; in as much as the average BTSCC found were 186.830 and 93.145 cel/ml, for afternoon and morning milking, respectively. Furthermore, a significant relationship (p<0.05) was found between the SCC of the afternoon milking and the BTSCC. The BTSCC values were lower than the limit values accepted for the United Sates and European countries, which suggest that under strictly controlled management policies the dairy herds from Antioquia could meet the international standards for milk exportation. Finally, further studies are required in order to precise and define the source of variations found between the SCC and BTSCC for both the morning and afternoon milking.
