Production and Economic Effects of Johne's Disease in Dairy Cows

Abstract

Johne's disease (paratuberculosis) (JD) is a chronic progressive bacterial enteropathy. Infected animals have generally been exposed to the organism at a very young age. Clinical signs of weight loss and diarrhea are often preceded by a period of months or years during which M. paratuberculosis organisms are shed in feces. The effect of subclinical JD on production and economic parameters has not been well characterized.

A study of randomly selected cull dairy cows was conducted at a large plant slaughtering cull cows from throughout the northeastern U.S. Johne's positive cull cows weighed less, produced less milk during their lifetime and less milk during their last lactation than did Johne's negative cull cows.