Efficacy of a Low Concentration Iodine Postmilking Teat Disinfectant Against Contagious and Environmental Mastitis Pathogens in Two Dairy Herds

Abstract

Two natural exposure herd studies were conducted at separate geographic locations to evaluate efficacy of a postmilking teat disinfectant that contained 0.25% available iodine. One study was conducted for 11 months in a commercial dairy with a high prevalence of contagious mastitis pathogens. Postdipping was compared with a negative control using a split-herd experimental design. The other study was conducted for 12 months in a research herd with a high prevalence of environmental mastitis pathogens. Postdipping was compared with a negative control using a split-udder experimental design. New intramammary infections by Staphylococcus aureus and Streptococcus agalactiae were reduced significantly in quarters with teats dipped in iodine compared to undipped teats in the herd with a high prevalence of contagious mastitis pathogens. However, the experimental teat dip was not effective against environmental pathogens in either herd. New infections by minor mastitis pathogens (coagulase-negative Staphylococcus species and Corynebacterium bovis) were significantly lower in quarters of dipped teats compared to undipped teats in both herds. No irritation or chapping of teats was detected and no adverse effects were observed. These data suggest that the low concentration iodine teat dip is effective against contagious pathogens and minor mastitis pathogens, but ineffective against environmental mastitis pathogens.

The influence of iodine teat dipping and an external teat sealant in heifers on bacterial isolation from quarter milk culture obtained post-calving

“…The results of the present study are not in agreement with (Eberhart et al, 1983;Nickerson et al, 1986;Oliver et al, 1991). However, it is difficult to compare those with our results since none of the other studies were conducted at the herd level.…”

A review of test protocols for the evaluation of teat disinfectants

“…This practice is widely accepted as a fundamental part of a successful mastitis control programme (Oliver et al . ; Oura et al . ; Leslie et al .…”

“…Oliver et al . () had the highest number of cows enrolled in their study with 374 cows, followed by Lago et al . () and Godden et al .…”

“…Oliver et al . () and Foret et al . () undertook their studies for the longest period of 9–12 months.…”

“…() used single intramammary quarter samples to determine new IMIs while Oliver et al . () used duplicate individual quarter milk samples and Foret et al . () used two consecutive quarter milk samples to determine new IMIs.…”