Supplementing cattle on pasture can be a good way to extend the grazing season.
By: Warren Rusche, SDSU Extension Cow/Calf Field Specialist
Available acres for summer grazing have been shrinking in recent years, particularly in areas where it is feasible to convert grass into cropland. The combination of fewer acres and strong cow-calf returns results in increased pasture costs, either for purchase or for rent. In some cases, feeding harvested feedstuffs is more economical than relying on pasture when full market rental rates are considered.
Feeding cows in a drylot is one strategy to deal with higher pasture costs. However, this approach is not without challenges. Pens need to have excellent drainage to avoid mud, and there is still the possibility of disease issues related to closer confinement and dust conditions. The added wear and tear on facilities and the cost of manure disposal also are considerations.
Bromegrass: An effective cool-season pasture supplement
Delivering supplemental feed to cows on cool-season pasture is one alternative studied by researchers at the University of Nebraska. In their research, cow/calf pairs grazed pastures at the recommended stocking rate for bromegrass in that area, or were stocked at twice the recommended rate and offered supplemental feed equal to 50% of the expected grazed forage dry matter intake.
The supplement used in this study was a 30:70 mixture of modified distillers grains and ground cornstalks (dry matter basis). The initial feeding rate was 0.6% of bodyweight on a dry matter basis. Researchers increased the amount fed on a weekly basis to account for differences in forage quality and quantity and for increased amount of supplement consumed by the calf.
Gains for both the cow and the calf were similar for the two treatments. The researchers reported that there were very few visual differences between treatments for pasture condition or the amount of forage left at the end of the grazing season.
These results suggest that feeding a mixture of distillers grains and low-quality roughage may be a viable strategy to support more cow/calf pairs on a fixed amount of pasture. This could be an option under drought conditions that limit forage supply or if the amount of pasture available will not support the number of pairs desired by the ranch management team.
An important fact to keep in mind is that this research was conducted on pastures dominated by smooth bromegrass. Even though in this study there were not any visual differences in pasture condition, it is possible that if the amount of supplemental feed was inadequate pastures could be overgrazed. Overgrazing native range containing warm-season grasses would have much larger negative effects compared to overgrazing a pasture that has already been invaded by cool-season tame grasses.