INFLUÊNCIA DA MASTITE SUBCLÍNICA SOBRE AS CARACTERÍSTICAS FÍSICO-QUÍMICA DO LEITE DE OVELHAS SANTA INÊS EM DIFERENTES FASES DA LACTAÇÃO: ESTUDO PRELIMINAR

This work assesses how subclinical mastitis can influence physical-chemical characteristics of milk from 18 Santa Ines ewes in different lactation stages. The animals were divided into two groups according to the condition of the glands: healthy glands (G1) and glands with subclinical mastitis (G2). The number of mammary glands was stable, although slightly higher after parturition. Research findings revealed no significant differences between levels of protein and electrical milk conductivity (P <0,05) in both cow groups, although the latter variable's values were higher for the second group. As regards healthy glands, percentage of lactose decreased in the last lactation stage. In the same period, the percentage of milk fat reduced significantly, which correlated with density. Evidence from the second group included lower dornic acidity levels, higher alkaline pH values, and higher chloride concentrations. Therefore, results show that subclinical mastitis caused little variation on the physical-chemical qualities of milk, which was probably due to the low pathogenicity of coagulase-negative staphylococci isolated from the milk samples.