Supplementation of Co-products for Cow-Calf Grazing Systems—Progress Report
The objective of this three year demonstration project is to evaluate the feeding of various corn co-products in cowcalf grazing operations in Iowa. Year one efforts included on-farm demonstrations at two southern Iowa farms. Both demonstration sites included a control group without coproduct and a group with supplementation, using existing management herds.
A demonstration in Lucas County involved three herds: a control with no supplementation (60 pairs), a group feeding 12 lb every other day of wet distiller’s grains with solubles (64 pairs), and another group feeding 6 lbs every other day of a 50/50 pellet with DDGS and SB hulls (80 pairs). Cows were fed from July 6 to September 15. Cost per head per day on the group fed pellets was $.185, with the cost of feeding wet DGS at $.045 per head per day. Dry conditions led to grass heights below 3.7 inches on the treated pastures on August 2, while the more diverse control pasture remained above five inches. Cows in all groups maintained body condition scores through weaning.
The demonstration in Union County involved two herds: a control group of 30 pairs and another group of 30 receiving 5 pounds of a DDGS based cube fed very other day. Cost of supplementation in the treated group was $.25 per head per day. Forage availability was higher throughout the grazing period at this location. From August 2 to August 25 there was a larger numerical increase in pasture heights in the supplemented pasture (1.5 inches), compared to the control pasture (.14 inches). Condition scores in both groups decreased slightly. Calf weight per day of age was higher on the control group (3.06 pounds/day) compared to the supplemented group (2.83 pounds per day), perhaps due to higher prevalence of fescue.
Supplementation at these low levels may be beneficial to the cattle, but no trends for grass substitution or animal performance can be drawn from this set of data.