The effects of heartwood extracts from biancaea sappan l. against coagulase-negative staphylococci (cons) and staphylococcus aureus isolated from subclinical mastitis in dairy goats
Subclinical mastitis is an important disease affecting milk quality in dairy goats, and slow to detect because
of non-clinical signs. Subclinical mastitis will progress to clinical mastitis which requires the treatments. The
treatment mainly uses the antimicrobial intra-mammary infusion, and it may cause antimicrobial resistance
problems. Thus, this study aimed to determine the change of milk composition and the antibacterial activity of
ethanolic extracts from Biancaea sappan L. heartwood against bacteria isolated from milk of subclinical mastitis
goats. Eighty-eight milk samples were classified into two groups; control (n=34) and subclinical mastitis group
or SCM (n=54) according to California mastitis test (CMT) score and somatic cell count (SCC). The study showed
that the percentage of lactose significantly decreased (p=0.002) in the subclinical mastitis goats, whereas the fat
contents significantly increased (p=0.014). The changing of milk protein, solids not fat (SNF) and total solid (TS)
contents were not observed. The bacterial identifications from milk samples revealed that the most commonly
isolated bacteria were coagulase-negative staphylococci (CoNS) (n=41, 78.9%) and Staphylococcus aureus
(n=7, 13.5%). The ethanolic extracts from B. sappan showed their antibacterial activity against isolated CoNS
and S. aureus with minimum inhibitory concentration (MIC) range were 0.125-4 mg/ml and 0.125-1 mg/ml,
respectively. These findings indicated that B. sappan ethanolic extracts potentially effected against major
pathogens of subclinical mastitis in dairy goats.