Flies cannot be completely eliminated in a livestock operation, but with good management, numbers can be dramatically reduced.  Fly control is important because flies can transmit diseases and cause livestock production losses.  They can also strain non-farm neighbor relationships. Effective fly control requires a multi-pronged or integrated pest management approach.  Sanitation is the foundation of any fly control program and can be combined with residual sprays, baits, light traps, biological control and in some operations, insecticidal ear tags and feed through products.  Below are links to some publications with more detailed information about specific fly problems, life cycles and management strategies.  Although some of the publications contain dairy in the title, the information is good and can apply to other livestock enterprises.    A couple of the articles have a little age but the principles of fly control are sound.  Whenever a chemical is mentioned make sure to check labels to ensure the insecticide is currently labeled for the intended use.

Barn Flies Management Guide: Cornell IPM Program

Management Guidelines for Dairy Cattle and Dairies: Mississippi State Extension

IPM for Fly Control in Dairy Barns: University of Maine Bulletin 5002

House Fly and Stable Fly Management In and Near Livestock Facilities: University of Nebraska, 2015

Fly Control Takes a 1-2-3 Approach: University of North Carolina Extension, 2017