Collaborating Producer: Odell & Lillian Raymond, Peace River Alberta
Research Coordinator: Dr. Akim Omokanye
There has been considerable interest in testing the grazing potential of warm season annual crops for their suitability in extending the grazing season in parts of the Peace. Reports from Peace region producers that have experience with grazing warm season crops, such as corn, have indicated that grazing cattle on corn can lower winter feed costs, reduce operating expenses and save time, as no harvesting is required and winter supplemental feeding is limited. In addition to these benefits, warm season crops like Proso and German millets can provide a high-yielding alternative to barley and oats, that can be utilized for greenfeed and swath grazing. Although, there are higher costs related to grazing warm season annual cereals, including high input costs of fertilizer and seed, the extension of the grazing season should still be considered an alternative low-cost method. The objectives of this trial were to evaluate warm season annual crop varieties for forage yield and quality and to examine the production cost of corn for grazing as a standing crop.
Methods The trial took place at Odell and Lillian Raymond’s farm, north of Peace River. Prior to seeding, the site had been a timothy-alfalfa pasture for 6 years and was used to winter cows for 2 years. In the fall of 2010, the site was Agrowplowed to a depth of 10 inches. Just before seeding, a broadcast fertilizer application of 75 lb N + 20 lb P/acre was done and the site cultivated with a vibra shank cultivator.
Eight Pioneer Round Up Ready corn varieties (39F44, P7213R, 39V05, P8107HR, P7443R, X70B144R1, X70B140R, 39M26), 2 millet varieties (Proso & German) and a forage sorghum variety (CFS30) were seeded.The corn varieties seeded had corn heat units (CHUs) varying from 2000 to 2400 (see Figure 1). The corn varieties occupied 30 acres of land, while Proso millet, German millet and forage sorghum occupied 1 acre each. All the crops were seeded on May 26, 2011. Corn was seeded with a 12-row corn planter at 32,000 kernels/acre. The corn planter was set at a spacing of 22 inches between rows. Millets and sorghum were seeded at 15 lb/acre. For corn, weeds were controlled with Roundup @ 400ml/ac and for millet and forage sorghum, 2,4-D amine was used 1 month after seeding. Results & DiscussionForage Dry Matter Yield All the corn varieties tested out yielded the two millet and the sorghum varieties (Figure 1).
Generally, corn forage DM yields were over 12 t/acre, with the top four ( P7213, 39V05, P7443R and X70B144R1) yielding over 16 t DM/acre. German millet had the least DM yield (3.9 t DM/acre). The DM yield of individual corn plant parts was not determined here, but reports have shown that at least 60 per cent of the dry matter yield of corn comes from the cob, grain and husk, while the leaf, stalk and tassel provide less than 40 per cent of the dry matter yield. Forage Quality The CP content of the crops varied from 7% for corn variety P7213R to 17% for the German millet variety (Figure 2).
Corn varieties generally had a lower CP content than those of millet and sorghum. Levels of protein and energy (TDN) for all corn varieties were within the recommended values required to maintain or provide gains for cows in mid and late pregnancy under normal winter conditions. The levels of CP obtained for millet and sorghum were either adequate or more than adequate for cows after calving. The energy levels of millet and sorghum varieties obtained in this study were only adequate for cows in the mid pregnancy state.
Cost of Production Comparison The cost comparison of seeding corn compared to oats is provided below in Table 1. Total direct (input) cost was lower for oats ($71.10) and higher for corn ($200.00), giving a difference of $128.90/acre between the two crops. This is expected because of the higher cost associated with corn seed and fertility. Corn has a high fertilizer requirement, but costs may be lower if manure is applied. Soil analysis may also help further reduce fertilizer cost. In this study, the producer was able to save 25 lb N + 20 lb P/acre in fertilizer by soil testing. The savings were due to the fact that the site had been grazed for 6 years and used to winter cows for 2 years prior to seeding the warm season crops.
Cow grazing days per acre and cost per cow per day are closely related to the maturity and yield potential of a corn crop. A mature corn crop with good yield potential will result in a higher number of cow grazing days and a lower cost per cow per day. In the present study, we estimated a cost of $0.56 per cow per day. This is a huge savings considering the fact that it costs a cow-calf producer an average of $0.90/cow/day in feed during the winter months. Grazing corn, like swath grazing, cuts down on machinery costs. There is no expensive harvest equipment and no feeding equipment required, just a low cost electric fence and limited yardage costs. Our collaborating producer feels that feeding corn is worthwhile for their farm and will be increasing the number of corn acreage in the future.