Summer annual grasses often are an important part of many hay and pasture plans. As you select a variety to plant this coming summer, choose one with a genetic trait that improves animal nutrition.
Summer annuals like Sudan grass, cane, sorghum-Sudan hybrids, forage sorghum and millet can produce high forage yields even under dry growing conditions. But they tend to be more stemmy and less digestible than many cattle producers prefer. Can they be made better?
The answer is – yes. A natural, genetic trait called BMR (or brown mid-rib) has been used in numerous varieties and hybrids of summer annual grasses for many years. This trait makes them more digestible and enables cattle to extract more energy from these forages.
It received the brown mid-rib name because the mid-rib or vein that runs down the center of each leaf has a brownish tint in summer annual grasses that have this genetic trait. Normally this mid-rib is a cream or whitish color.
The important characteristic is how the BMR gene affects forage quality. Grasses that have the BMR gene produce less lignin than normal plants. Lignin is a complex compound that attaches to fiber components like cellulose in the plant and make it less digestible.
Since plants with the BMR gene produce less lignin, more of the fiber can be digested by your cattle, increasing the energy or TDN value of this forage. Grazing studies in Texas found yearlings to have a 12% greater daily gain when grazing a BMR forage compared to a conventional forage. In addition, animals eat more of the stems, reducing waste.
The BMR gene has little other effect on these plants, so they respond like normal plants to other management practices, like planting rate, fertilization and harvest timing. Give BMR forages a try and I think you will be pleased.