Horn fly and face fly numbers will continue to build for a few weeks, which will put pressure on control programs. It is a good time to evaluate the pasture fly situation in your herd; check during the early afternoon on a sunny day (Figure 1). Less than 100 horn flies per side and less than 10 face flies per head is a good target for animal protection. Consider an adjustment or supplemental measure if fly numbers exceed these guidelines.
Late season fly control is important. Pasture flies are approaching peak numbers for the season, so their impacts are near maximum levels. Also, exposure of flies to less than recommended rates of insecticide due to less effective treatment selects for resistant individuals and increased chance for control failure. To ensure flys are kept in check, evaluate management options by following suggestions:
Insecticide-impregnated cattle ear tags can provide 12 to 15 weeks or protection. Effectiveness may be running out in herds that were tagged a little early in the season.
Feed-thru insecticides in mineral supplements require a minimum level of daily consumption by each animal. Be sure that the product is available and that the consumption rate appears to be on-target. This alternative is based on controlling horn fly and face fly maggots that develop only in cow manure. Face flies and horn flies can move a mile or two, so action may be needed to control flies that move in from nearby herds. Provide supplemental control, as necessary.
Be sure that self-applicators are charged and working. The fly wipe in Figure 2 appears to be dry so the reservoir tank may need to be filled. In some cases, dust can build up enough to reduce the wicking action in wipes and oilers. Be sure dust bags have not been damaged and that the insecticide in them is dry and flowing.
Pour-on and spray applications generally provide about 4 weeks of fly control. Check the last treatment date and be sure doses are measured accurately.
By Lee Townsend, Extension Entomologist
Fall is the time of the year to establish winter annuals. For wheat, seeding should be delayed until October to avoid Hessian fly infestations, but most winter annuals used for forage should be seeded much earlier. For example, cereal rye seeded in mid-August can be grazed as early as late September. The rye then provides high-quality grazing into December and continued growth the following late winter/early spring. Combining annual ryegrass with rye provides faster regrowth between grazings and a longer grazing season in the spring.
For extremely high-quality pastures, brassicas are an excellent forage crop. Brassicas include turnips, rape, kale and others. The quality of brassicas is so high though (85% TDN), added fiber is needed to slow down passage rate. Fiber can be free choice hay, but a more economical option is simply to plant cereal rye or oats with the brassicas. A popular mixture is an August planting of 1 bu/acre spring oats, 1 bu/acre cereal rye, and 4-5 lbs/acre of turnips (add 50-60 lbs actual N/acre at planting). This mixture provides high quality because of the turnips, the oats and rye provide fiber and excellent fall growth, and the rye survives the winter for early grazing next year. Winter oats usually do not survive KY winter, so spring oats are recommended. To make this mixture even better suited for pasture production make sure to plant a grazing type turnip that regrows after grazing (Purple Top turnips have good production, but do not grow back after the first grazing).
By Ray Smith
Excerpt from Cow Country News August 2016
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