Impact of Intramammary Infection of Serratia Species on Milk Production, Somatic Cell Count, and Survival in Dairy Cattle

Abstract

Serratia species are gram-negative bacilli commonly found in soil and water. They have been associated with disease in humans, companion animals, and dairy cattle. In dairy cattle, infections have originated in the dry or lactation period in both small and large herds. The infection can result in clinical and subclinical mastitis. Clinical cases occasionally cause severe symptoms such as hard, hot quarters and systemic signs of illness or death; however, subclinical cases are more common. Individual infections have been reported to last as long as 10 months. Although some reports have suggested successful treatment with neomycin, most studies suggest that a majority of Serratia spp infections cure spontaneously. Most studies have described individual herds and focus on the source of the organism. Little is known about the long-term impact of intramammary infections of Serratia spp on milk production, milk quality, and herd life of affected cows. The goal of our study is to analyze the effect of Serratia spp detection on milk production, somatic cell count (SCC), and survival across multiple herds.