The Preliminary Study on Antibacterial Efficacy of 4 Organic Acids on Mastitis Pathogens in Dairy Cattle

Abstract

The aim of this study was to evaluate the antimicrobial efficacies of formic acid, lactic acid, malic acid and citric acid against mastitis-caused pathogens. Pathogens used in this study were Klebsiella spp, Escherichia coli, Streptococcus dysgalactiae, Streptococcus uberis and Staphylococcus aureus. Minimum bactericidal concentration (MBC) and reduction of total bacterial count were examined. The results revealed that the minimum bactericidal concentration (MBC) of formic acid against all tested pathogens was 0.191%v/v indicating the best bactericidal performance. In comparison, the following orders were 10.625% lactic acid, 12.37% malic acid and 12.43% citric acid, respectively. These acids at their best solutions were then used to test their antimicrobial efficacies on teats of dairy cattle. It was found that 12.43% citric acid, as well as 10.625% lactic acid, showed the best performance due to the reduction rate at 1.15 log10cfu/ml.(P<0.05) and 1.69 log10 cfu/ml (P=0.32), respectively. On the contrary, formic acid and malic acid were significantly unable to reduce the total bacteria compared with the control group. In conclusion, the results in this study revealed that citric acid and lactic acid have potential antimicrobial effects against mastitis-caused pathogens in dairy cattle.