by R. L. Dalrymple
Crabgrass is one of the highest quality warm-season forages available. It is usually well over 20 percent crude protein and nearly 80 percent digestible in early grazing stages during May and June. Protein content of immature plants stays above 10 percent until August or September. Digestibility stays over 60 percent for much of the summer and can be as much as 10 percentage points higher than that of bermudagrass. In the vegetative stage, crabgrass is one of the most palatable of all grasses. The forage also can be managed for dense growth, which is very important for top-level intake and animal performance.
In our trials, one group of stockers gained 2.80 pounds per day for two months on early crabgrass, and another group gained 1.85 pounds per day during long-term 125-day grazing. During the drought of 1980, stockers gained 1.90 pounds per day for ninety days, and much of that gain was attributable to dried crabgrass. Winter pasture stockers with a good gain rate were switched to early crabgrass and gained 2.40 pounds per day, which means crabgrass might be used in many integrated forage situations.
One winter pasture was successfully double-cropped cereal rye, which produces until early crabgrass germination time, and crabgrass summer pasture for fifteen consecutive years. These planned pastures need early September and late April or early May tillage, early and proper fertilization, and good grazing or haying practices.
On sandy lands, the double pasture can be switched from rye to crabgrass without the spring tillage; crabgrass emergence will be delayed slightly. Under good rotational grazing, the rye is grazed in a given paddock when crabgrass emerges, releasing the crabgrass to produce later grazing material. Forage is often deficient when rye is switched to crabgrass; an alternate pasture is needed to bridge the gap.
When stockers go from winter pasture to crabgrass, it is wise to have an early crabgrass pasture that is not part of a double crop, reducing the possibility of deficient spring forage. Crabgrass that does not follow winter pasture emerges about four weeks earlier than that in a double-crop pasture. Whether stockers are kept on crabgrass or other summer forages depends heavily on their weight and on marketing options. Crabgrass is excellent forage to feed winter pasture stockers from July to fall, when they are switched from crabgrass to winter pasture.
When annual ryegrass is the winter pasture, it severely outcompetes early crabgrass growth because its production terminates later than that of cereal grains. Annual ryegrass growth overlaps that of ryegrass pasture by about eight weeks. Crabgrass should be grown separately because ryegrass can delay its early growth until the hot, drier part of summer. If precipitation is good, however, that problem is not as severe.
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