Efficacy of Two Acidified Chlorite Postmilking Teat Disinfectants with Sodium Dodecylbenzene Sulfonic Acid on Prevention of Contagious Mastitis Using an Experimental Challenge Protocol

Abstract

Two acidified sodium chlorite postmilking teat disinfectants were evaluated for efficacy against Staphylococcus aureus and Streptococcus agalactiae by using National Mastitis Council experimental challenge procedures. The effect of these teat dips on teat skin and teat end condition was also determined. Both dips contained 0.32% sodium chlorite, 1.32% lactic, and 2.5% glycerin. Dips differed in the amount of sodium dodecylbenzene sulfonic acid (0.53 or 0.27%) added as a surfactant. Both dips significantly reduced new intramammary infection (IMI) rates compared with undipped controls. The dip containing 0.53% dodecylbenzene sulfonic acid reduced new IMI by Staph. aureus by 72% and Strep. agalactiae by 75%. The dip containing 0.27% dodecylbenzene sulfonic acid reduced new IMI by Staph. aureus by 100% and by Strep. agalactiae by 88%. Changes in teat skin and teat end condition for treatment and control groups varied in parallel over time. Teats treated with either teat dip had higher mean teat skin and teat end scores than control teats at some weeks. However, teat skin and teat end condition did not tend to change from the start to the completion of the trial. Application of the two new postmilking teat dips was effective in reducing new IMI from contagious mastitis pathogens. (Key words: teat dip, contagious mastitis, chlorous acid)

A review of test protocols for the evaluation of teat disinfectants

“…Oura et al . () had an additional fourth standard where five consecutive samples contained >1 cfu/mL of the same pathogen were considered a new IMI. This was different to Leslie et al .…”

“…Oura et al . () applied the suspension for 7 days each week after the morning milking and Leslie et al . (, ) applied the suspension for 7 days each week, but after morning and afternoon milking.…”

“…agalactiae was isolated from a clinical intramammary quarter, (2) two consecutive samples yielded >500 cfu/mL of the same pathogen, or (3) three consecutive samples contained 100-400 cfu/mL of the same pathogen. Oura et al (2002) had an additional fourth standard where five consecutive samples contained >1 cfu/mL of the same pathogen were considered a new IMI. This was different to Leslie et al (2005Leslie et al ( , 2006, who confirmed a quarter as positive for new IMI if any of the following criteria were met:…”

“…However, differences in application schedules were observed between studies. Oura et al (2002) applied the suspension for 7 days each week after the morning milking and Leslie et al (2005Leslie et al ( , 2006 applied the suspension for 7 days each week, but after morning and afternoon milking. Studies by Foret et al (2003) and Boddie et al (2004) applied the suspension for 5 days each week after the afternoon milking.…”

“…Teat disinfectants have been used to reduce the number of new IMIs caused by mastitiscausing pathogens (Schmidt et al 1984;Foret et al 2005). This practice is widely accepted as a fundamental part of a successful mastitis control programme (Oliver et al 1991;Oura et al 2002;Leslie et al 2006). Teat disinfectants may be used pre-and/or postmilking.…”