Células somáticas no leite em rebanhos brasileiros

Abstract

A survey of data of the Lactation Physiology Laboratory of ESALQ - USP, Piracicaba, SP, Brazil was performed to characterize the somatic cell count (SCC) of herds. Descriptive statistics was used to analyze results of 7941 records collected between December 1996 and July 1998. The SCC mean was 641 thousand cells mL-1, standart deviation 767 thousand cells mL-1. The log2 transformation was also applied to SCC values, a new mean was calculated and then again transformed into SCC (307 thousand cells mL-1). This was the best way to present the real SCC values of the herds. The population of herds are distributed according to SCC count, considering the SCC limits of 250, 500, 750, 1000, 1250 e 1500 thousand cells mL-1, in the following percentages: 26, 53, 71, 83, 89, 93%. The quartiles of the samples were 25, 50, 75, 90, 95, 99 e 100% showing 244, 468, 815, 1302, 1797, 4099, 9223 thousand cells mL-1 respectively.