Stable fly activity on California dairies

Stable flies are blood-sucking pests of cattle, horses, and other warm-blooded animals in many parts of the world. The pain associated with stable fly bites upsets livestock feeding patterns, reducing weight gains, feed efficiency, and milk production. Although few studies have been done on such losses, reductions of up to a half pound a day in weight gain and 30 to 40 percent in milk yield have been observed.