Effect of pre-milking teat disinfection on new mastitis infection rates of dairy cows

Abstract

BackgroundThe practise of teat disinfection prior to cluster attachment for milking is being adopted by farmers in Ireland, particularly where there are herd issues with new infection rates. Pre-milking teat disinfection has been shown to reduce bacterial numbers on teat skin and to be most effective against environmental bacteria such as Escherichia coli and Streptococcus uberis. A split udder design experiment was undertaken on two research herds (A = 96 cows: B = 168 cows) to test the benefit of pre-milking teat disinfection on new mastitis infection levels. The disinfectant was applied to the left front and right hind teats of all cows in each herd and the right front and left hind teats received no disinfectant treatment prior to milking over a complete lactation. Individual quarter foremilk samples were taken on 5 occasions during the lactation and all clinical cases were recorded. The presence and number of staphylococcus and streptococcus bacteria on teat skin of a random sample of experimental cows (n = 20) was measured on 3 occasions during lactation (April, June, and October).ResultsPre-milking teat disinfection had no significant impact on quarter SCC and new infection rates (P > 0.05). The median SCC was 169 (95% CI = 144–198) × 103 cells/mL and 170 (95% CI = 145–199) × 103 cells/mL for disinfected teats and non-disinfected teats, respectively. There were no differences in SCC observed between herds (A = 161 (95% CI = 127–205) × 103 cells/mL; B = 169 (95% CI = 144–198) × 103 cells/mL) over the complete lactation. Bacterial levels on teat skin were reduced significantly with pre-milking teat disinfection compared to teats receiving no disinfectant (P < 0.001). Total infections (clinical and sub-clinical) were similar for disinfected teats (n = 36) and not disinfected teats (n = 40), respectively. Staphylococcus aureus (n = 47) and Strep. uberis (n = 9) were identified as the predominant bacteria in quarter foremilk samples with both clinical and sub-clinical infections.ConclusionSCC and new infection rates were similar in non-disinfected teats and disinfected (pre-milking) teats. The routine application of pre-milking teat disinfectant in pasture-grazed herds is unlikely to be of benefit where herd SCC is below 200 × 103 cells/mL.

Are some teat disinfectant formulations more effective against specific bacteria isolated on teat skin than others?

“…High bacterial contamination may increase the chances of more bacteria entering the teat orifice and causing infection [1]. The removal of bacteria pre- and post-milking can lower the occurrence of new intramammary infections (IMI’s) [2, 3]. Therefore, determining the efficacy of teat disinfectant products against bacteria naturally present on teat skin is important.…”

“…Therefore, determining the efficacy of teat disinfectant products against bacteria naturally present on teat skin is important. Teat swabbing has been used to determine the effect of pre-milking teat preparation treatments [1, 2, 4–6], enumerate and identify bacteria present on teat skin surface [7–11]. Previous studies focused on evaluating pre-milking teat cleaning procedures.…”

“…Before (PRE) the application of a test teat disinfectant, a composite teat skin swab was collected from all 4 teats. For PRE swab samples, swabs were drawn across the teat orifice and down the side of each teat avoiding contact with the udder hair and cows flank [2, 10]. All teats of the cow were then immersed in a test teat disinfectant using a teat dip cup.…”

The Benefits of Teat Dipping as Prevention of Mastitis

“…Barkema et al (1998) and Kelly et al (2009) reported that washing with a towel before teat dipping was one of the important factors related to the low number of Somatic Cell Count (SCC). Supar and Ariyanti (2008) added that the transmission process of (Gleeson et al, 2018). Teat dipping after milking is primarily given to infected groups and has been shown to be very effective in preventing the spread of mastitis (Galton, 2004).…”

Efficacy of a Lactobacillus-Based Teat Spray on Udder Health in Lactating Dairy Cows

“…Teat disinfection that effectively and safely reduces bacterial load on teat skin reduces the risk of mastitis in the herd (17)(18)(19), improves teat skin condition (9), and reduces the risk of milk contamination (20). The observed efficacy of a teat disinfectant will vary depending on the production system, season, and the particular mastitis causing pathogens affecting the herd (18,21,22).…”