Weekly, Oklahoma State University Extension Beef Cattle Nutrition Specialist Paul Beck offers his expertise on the beef cattle industry. This is a part of the weekly series known as the “Cow-Calf Corner.” Today, he talks about nutritional qualities of native range.
The nutritive quality of native range in the Southern Great Plains declines during the mid to late summer. Crude protein and digestibility of the forage increases in the spring as it greens up and starts summer growth beginning in April, peaking in May, and then steadily declines throughout the rest of the year.
Performance of stocker calves on native range declines from highs of 2 pounds/day during early summer to less than one pound per day through the late summer. Deficiency in dietary protein causes dramatic reductions in forage intake and digestibility. A small amount of high protein supplement corrects the protein deficiency increasing both forage intake and forage digestibility when adequate forage is available. Our research indicates that feeding 2 to 2.5 pounds of extruded distiller’s grains cube supplement per day (or feeding 5 to 6 pounds/head 3 days per week) to growing calves on native pasture can increase performance in the late summer by 0.75 to 1.0 pounds/day requiring only 2.5 to 3.5 pounds of supplement per pound of added gain.
Bermudagrass and other introduced pasture forages common to eastern Oklahoma and the Southeast do not have the same nutrient profile as native pastures through the summer with crude protein values over 12% even during the late summer. The fiber content of the bermudagrass increases as the summer progresses resulting in reduced forage digestibility and limited performance. Our research in Eastern Oklahoma steers showed feeding 5.8 pounds of supplement 3-days per week (a 2.5 lb/head daily supplement rate) increased gains of growing steers were increased by 0.5 to 0.7 pounds per day, requiring 5.3 and 3.5 pounds of supplement for each pound of added gain, respectively.
Because protein content of the forage is usually adequate for growing calves in the fertilized bermudagrass throughout the summer, steers don’t respond to added protein like they do on native range. The increase in performance we saw is through the addition of energy to the diet to offset the reduced digestibility of the forage during the late summer. This decreases the efficiency of supplementation on introduced pastures compared with native range.
Supplementation of grazing calves during the late summer can be highly profitable even in years with high input costs. The response by growing stocker calves may not be the same on differing forages and pasture types so the economics of the supplementation program need to be evaluated based on the types of pasture and supplement, the supplement cost, and the margins of the stocker cattle enterprise based on the current markets.
Below, SunUpTV highlights research on the influence of supplementation and stocking rate on performance and economics of stocker cattle operations at the Marvin Klemme Range Research Station on October 17, 2020.
