Dale Watson
Commercial Agriculture Beef and Livestock Specialist
University of Missouri Extension




Dale's Country Trails

Search Country Trails

Previous Issues of
Dale's Country Trails

Other Ag Newsletters from University of Missouri Extension in Central Missouri

Ag Connection

Decisive Marketing

Ag Page for Central Missouri UO/E Ag Page for Central Missouri
UO/E in Central Missouri University of Missouri Extension in Central Missouri

MailboxComments or Suggestions?
Please send your comments and sund suggestions to Dale Watson, Commercial Agriculture Beef and Livestock Specialist, University of Missouri Extension, 111 N. Mason, Carrollton, MO 64633, call 660-542-1792, or send messages by e-mail to: watsond@missouri.edu.
For the Week of
April 15, 1999

Flies Have Early Start for '99

Fly control seems to be on the mind of many producers. Observation of these little creatures gives the appearance that their presence throughout the grazing season of 1999 will definitely be with us. Many practices for effective fly control continue to be discussed. Many producers remember last year. This is normal judging from the number of blue or discolored eyes in many of the replacement females.

The eye/fly problem was discussed at most of the beef rendezvous we held throughout North Central Missouri. This topic was approached with different opinions from beef producers. One thought that emerged at each session was to eliminate all the possible causes of eye problems through an effective immunization program. Is it possible that a series of immunizations given early in life to the calf and followed with booster injections to raise the titer will assist with reducing the initial start of eye problems in the 1999 spring calf crop? The consensus of the group was that neither the flies themselves nor the seed heads of the cool season grasses were the initial cause of the eye irritation. Both of these will contribute to the irritation and spread of the problem after the malady is already established within the herd. 

An immunization program that includes IBR, BVD, PI3, and the usual 7-8 way clostridial vaccine will be very beneficial in reducing the initial start of the eye problem. This requires extra work and assistance from management. However, preventing eye problems is much easier than combating the problem after it gets a raging start within the herd. Eyes that are or near normal add additional value at marketing. Blind calves are not in high demand regardless of the marketing time.

Generally we can find variation of eye watering or a mild form of cloudy eyes in most herds. Controlling flies has been a concern for many years. It is essential that management assist the cow with fly control.

One method that seems to work is the fly trap. However, this method requires the location of this device so that the cattle are forced to travel through the trap as they go to water. An electric wire can be constructed to assist with directing the livestock through the trap. The use of fly strips, wicks, or bullets located in high traffic areas are effective. However, if you are using this method don’t forget to treat the strips with an approved fly repellent. This is one area that producers often fail to follow up on as the planting and harvesting season for crops and hay progresses.

If you plan to use fly tags it is best to place these in the herd just prior to the onset of the heavy infestation of flies. Placing them in the ears before the cattle go to grass tends to reduce the effectiveness of this material as the summer grazing season progresses. Another important point to consider is to rotate the product you are using. Flies tend to build up immunity to a single product, which reduces the effectiveness of the control.

Feeding some form of larvacide in the mineral will break the life cycle within the herd. However, if your neighbor isn’t feeding a similar material then the flies seem to cross the fence and create a problem in your herd.

The best method I know of is to be consistent with product application and treat according to directions. Continuous treatment throughout the grazing season does more than just control flies. Frequent observation of the herd is a positive management tool under any circumstance.

University of Missouri ExtensionDale's Country Trails - April 15, 1999
http://outreach.missouri.edu/agconnection/DCT/CT041599.html -- Revised: April 20, 2004