On the Blog

Beat the buzz this fly season

Let’s fast forward in time to July. Imagine it is a comfortable, sunny summer day. Rancher A goes out to check his cows on pasture. Calves are looking good, cows are scattered out grazing and the bulls he turned out last week are covering the cows as needed. Rancher B goes out to the pasture to find his cattle crowded up trying to find shade, with his bulls under the lone tree on the far side of the pasture. Tails are swinging, heads and ears are moving constantly to bat at the flies. Calves look a little stressed and it appears he will need to bring a few in to treat for signs of pinkeye. Which Rancher would you prefer to be?

What if I told you there was just one difference in these operations? Rancher A was proactive and started supplementing with a CRYSTALYX® fly control barrel before fly season started, and Rancher B now wishes he had.

Flies are not only a nuisance but are economically devastating.  Flies spread disease, cause stress and result in a loss in productivity. While the house, stable and face fly all contribute to poor performance, the horn fly specifically is one the most economically damaging pests of pasture cattle, costing cattle producers around $1 billion each year. An adult horn fly lives 2 to 4 weeks and takes 20 to 40 blood meals per day. This loss in blood is a loss in nutrients from the animal, resulting in poor weight gain, milk production, etc. that can impact productivity. The cost of labor, treatment and potential loss of income for an outbreak of pinkeye spread by face flies, and the economic impact can be severe.


Flies and developing heifers

When we think about fly control, our cow herd may be the first group that comes to mind, rightfully so as we expect our returns coming from the calves they wean and getting bred back to remain in the herd. We also need to keep in mind the importance of fly control for our developing heifers. Replacement heifers are critical to the future profitability of a beef operation. Typically a return on investment isn’t seen until maturity and they wean a series of calves. While growing, heifers are often faced with horn fly populations similar to the cow herd. As heifers develop, hormonal changes occur including increases in estrogen and progesterone levels. It has been shown that as estrogen levels rise, fly irritation also increases making cattle in standing heat especially vulnerable.

Additionally, horn flies may lead to mastitis and blind quarters in heifers. This may be caused by the flies feeding on the blood vessels of the teat, causing irritation and eventually scabs to develop leading to staph aureus bacteria to incubate in the teat structure. The bacteria can damage the milk-producing tissues, leading to blind quarters in the udder. As the heifer calves and lactates, this blind quarter causes a drop in milk production, which may be unfavorable to calf weaning weights.


Breaking the fly life cycle

Feed through fly control is both safe and effective. Cattle will consume the supplement containing the fly control. The active ingredient will pass through the animal’s digestive system and into the fresh manure, where flies lay their eggs. Depending on the specific fly control used, it will either kill the larvae or prevent flies from developing into biting adult flies. It is important to remember that control is key and there may still be flies even while doing everything you can to prevent them. The economic threshold for treatment is 100-200 flies per head.


Approximate dates of fly emergence


When and how to start

Ideally, feed through fly control should begin 30 days before fly emergence, which will be earlier in the year in the southern states compared to the northern states as the map demonstrates. It is recommended to continue providing the fly control throughout the summer and into the fall until the fly population starts to die off.

The consistent intake of CRYSTALYX® makes it an excellent vehicle to deliver fly control. CRYSTALYX® offers several excellent options for fly control combined with high quality nutrition. ClariFly® and Rabon® additives will kill all 4 flies, while Altosid® IGR specifically targets the horn fly. ClariFly® and Rabon® are also approved for use in horses. The various CRYSTALYX® Blueprint® formulas with fly control contains ClariFly®. The addition of garlic has been shown to repel flies as well, but will not kill them. Mineral-lyx® GAR or Hi-Mag Fescue-lyx® GAR contains the garlic additive. For additional information on fly control products or to find your local CRYSTALYX® dealer, go to www.crystalyx.com.