Evaluation of a povidone-iodine and chitosan-based barrier teat dip in the prevention of mastitis in dairy cows

Abstract

Postmilking teat dip is an important tool used to prevent mastitis in the modern dairy industry. In this study, we evaluated the in vitro and in vivo efficacies of a barrier teat dip containing povidone-iodine and chitosan for the prevention of mastitis. In experiment 1, we evaluated the antibacterial effects of chitosans with different molecular weights against six mastitis-causing bacteria based on the minimal inhibitory concentration test. The results showed that 50 kDa chitosan had the maximum antibacterial activity compared with 5, 150 and 350 kDa chitosans. In experiment 2, the inhibition zone test indicated that the barrier teat dip with 4.0% povidone-iodine and 1.0% chitosan had higher (P0.05) in SCC, somatic cell score (SCS) or other milk quality indicators were observed between nonbarrier and barrier teat dip treatment teats throughout the experiment. At the end of experiment 4, compared with nonbarrier teat dip group, a reduction (P0.05) in milk qualities or clinical mastitis incidence were detected between groups. Bacteriological analysis demonstrated that the barrier product containing povidone-iodine and chitosan reduced the subclinical mastitis infection prevalence induced by mastitis pathogens. This effect was mainly due to the reductions in Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia fergusonii infections. Overall, the data indicated that a barrier teat dip containing 4% povidone-iodine and 1% chitosan was more effective than 10% povidone-iodine in preventing subclinical mastitis.

Keywords

• mastitis
• povidone-iodine
• chitosan
• barrier postmilking dip