That's exactly how much you're losing if your herd is Johne's positive and at least 10% of your cull cows show clinical signs of infection. As the chart (below) shows, even a Johne's positive farm with 100 cows will experience a significant economic impact. The losses are astronomical for larger herds. In fact, the USDA Economic Research Service estimated that based on production costs, the middle 50% of dairy producers had net earnings of $243 per cow in 1993. That means at $227 per cow Johne's could be devouring 93% of your profits!
 

# of cows	100	500	1,000
Cost per cow *	$227	$227	$227
Cost per year	$22,700	$113,500	$227,000
* Based on 10% or more of cull cows in Johne's positive herd showing clinical signs of infection.

A Johne's positive herd averaging less than 10% of cull cows showing clinical signs of infection still loses $40 per cow per year. While dramatically less than $227, it's money that most farmers in today's world of stagnant milk prices can't afford to lose. The chart (Below) shows yearly losses for such farms. Pasteurization makes economical sense for 100 cow farms losing $40 per cow per year, let alone larger farms or farms with a more prevalent Johne's problem.

# of cows	100	500	1,000
Cost per cow *	$40	$40	$40
Cost per year	$4,000	$20,000	$40,000
* Based on 1-10% or more of cull cows in Johne's positive herd showing clinical signs of infection.