Economics of Field Pea Supplementation for Cattle Grazing Crested Wheat Grass

Field peas are widely grown in the western part of Nebraska because they offer benefits for wheat production in subsequent years. However, typical field pea markets can become saturated and new avenues are being explored. Field peas contain 20-25% CP, of which approximately 40% is RUP. A two year experiment was conducted comparing field peas to dry distillers grains with solubles (DDGS) as an RUP supplement for yearlings grazing crested wheat grass in the summer. The objective was to establish a price producers could pay for field peas relative to DDGS. The first year 112 heifers (294 kg; SD = 34.6) grazing crested wheat grass pastures (n = 12) were used in a 2×2 factorial design. The grazing season began May 20 and ended September 19. The second year of the study used 114 spayed heifers (306 kg; SD = 16.3) and supplementation began May 23 and ended September 7. Cattle were blocked by BW. Treatments included field peas or DDGS supplemented daily at either 0.4% or 0.8% of BW. Supplement amount was prorated for 6 days of delivery and fed in bunks. Pasture was the experimental unit and cattle were rotated every two weeks to remove any effects due to pasture. Body weights were collected on 2 consecutive days and averaged for both beginning and ending BW. A 1-d interim BW was also collected to adjust the amount of supplement offered. All other procedures were the same in years 1 and 2. Each treatment was replicated six times (3/yr) over the two year study. Effects of weight block and year were not significant (P ≥ 0.26) and were removed from the model. There was also no interaction between type and level of supplement (P = 0.27). Level of supplement was not statistically significant (P = 0.20), cattle fed field peas at 0.4 or 0.8% of BW gained 0.97 and 0.98 kg/d, respectively. Cattle fed DDGS gained 1.02 and 1.15 kg/d for the 0.4 and 0.8% of BW levels, respectively. There was a significant difference in ADG due to type of supplement (P = 0.03). Field pea supplemented heifers had 10% lower ADG compared to DDGS supplemented heifers. Economically, this means if corn is priced at $124.58/ 909 kg DM, and DDGS is priced similar to corn, a producer should pay $112.13/ 909 kg DM, or $2.89/ 27 kg, for field peas.