It’s Not Too Early to Start Thinking About Fly Control

Courtesy of the California Dairy Quality Assurance Program

The California Dairy Quality Assurance Program (CDQAP) released its February update, which can be read in its entirety here.
 
It’s Not Too Early to Start Thinking About Fly Control
By Dr. Michael Payne, UC Davis, School of Veterinary Medicine and Director, CDQAP
 
Storms have continued to pelt California and producers have understandably focused on managing the dairy during heavy rainfall. These wet conditions however, when combined with spring’s warmer weather, also make for perfect fly breeding habitat. Some flies can complete a full life cycle in as little as 7 days.
 
Here are a few key fly management concepts:
 
Flies can cost you money. Biting flies, including stable and horn flies, reduce feed intake. Depending on the number and types of flies, milk production losses can range from negligible to up to 30%.
 
Flies can transmit disease. House flies and face flies can transmit bovine pinkeye, particularly in youngstock. Flies can also act as a vector for mastitis pathogens, especially summer mastitis in heifers. Flies played a role in the recent Vesicular Stomatitis outbreak in California.
 
Know your fly enemy. To determine if additional investment in fly control is warranted, it is essential to first determine the types of flies present and the fly burdenon your particular dairy. You veterinarian, field staff or UCCE advisor can help.
 
Start at the source. Because 80% of a dairy’s fly population exist in the pre-adult stages in wet organic matter, good sanitation is the most cost-effective way to control all types of flies. Without managing the source it’s virtually impossible to control flies using only pesticides.
 
Common problem areas. Greatest fly reduction is typically achieved managing manure storage, calf hutch and silage areas. Allowing manure to dry before stacking or (if piled wet) ensuring that piles reach composting temperatures are good tools. Diverting clean storm water and maintaining drainage in pens and silage areas is effective. Removal of old feed and repair of leaking water tanks can also help.
 
For a detailed review of fly control see CDQAP’s Dairy Fly Control and Your Bottom Line, and UCCE’s Predicting and Controlling Stable Flies on California Dairies.