To determine the effect of sprinklers on faecal shedding of Escherichia coli (E. coli) O157:H7 and Salmonella in lactating dairy cattle.Methods and Results:
Sprinklers were applied to lactating dairy cattle on two farms at either the feedbunk or in the holding pen prior to milking. Faecal samples were collected approx. 1 and 4 weeks following initiation of sprinkler treatments for culture of E. coli O157:H7, Salmonella and Enterococcus. No treatment differences were observed for E. coli O157:H7. Salmonella was higher (P = 0·11) in the control treatment on day-7 whereas on day-28, the bunk sprinklers increased the number of Salmonella positive cows. Salmonella prevalence decreased (P = 0·0001) on day-5 and when examined across days in cows exposed to sprinklers prior to milking. Antimicrobial susceptibility screening found very few isolates that were multi-drug resistant. All Enterococcus isolates were susceptible to vancomycin.Conclusions:
This study demonstrated a significant decrease in faecal prevalence of Salmonella in lactating cattle following exposure to sprinklers administered prior to milking.Significance and Impact of the Study:
Identification of current dairy management techniques that are also effective in reducing on-farm prevalence of pathogenic bacteria could have significant food safety and environmental implications.