Alternative Feeds: Forage Yield & Feed Value of Brassicas and Warm Season Cereals

Collaborating Producer: Grant & Audrey Gaschnitz, High Prairie

Research Coordinator: Dr. Akim Omokanye

From: Peace Country Beef & Forage Association 2012 Annual Report

The costs associated with forage, feed and feeding systems are the largest contributors to total cost of production in a cow/calf enterprise. Many options are available to producers to reduce feed cost, particularly in the later part of fall and during winter. These options have always relied on conventional annual forage feed types such as oats and barley for greenfeed, silage and swath grazing. In recent years, weather in parts of the Peace region, particularly during the growing season has been erratic. Yearly fluctuations in the amount and distribution of precipitation received could have severe effects of available forage and grain feed for beef cattle production. Research and demonstrations on alternative feed sources and feeding strategies need to be explored and utilized for cow/calf feeding systems. These will further help us identify other means to reduce these costs as well as to identify those crops with potentials for the Peace region. In this report, the agronomic adaptation & feed value of a variety of crops are presented and discussed.


Site: A total of 60 acres was used to seed the following crops: Tillage Radish®, purple top turnips, red Proso millet, forage sorghum, 3 corn hybrids (BrettYoung Fusion RR, BrettYoung Edge R and Pickseed 2219RR), Tillage Radish®-Cowboy barley intercrop, Boyer oats (check) and Cowboy barley. Seeding was done between May 28 and June 28, 2012, with the corn hybrids, forage sorghum and Proso millet being seeded earlier (May 28 –29) than the other crops. The entire site received 65 lb actual N/ac + 30 lb actual P/ac through broadcast application. The soil test indicated sufficient amounts of K and S, so both K and S were not included in the blend. The trial involved a researcher design and producer manage type of on-farm field studies.

Seeding Rates and Crop Arrangement: Corn (30785 kernels/acre), Proso millet @ 20 lbs/acre, purple top turnips @ 2.5lbs/acre, Tillage Radish® @ 8lbs/acre, Boyer oats @ 2.5 bushels/acre, forage sorghum @ 20lbs/acre. The crops were arranged in a randomized block design. Corn hybrids were planted with a John Deere hoe drill, which was adapted to planting corn kernels. The John Deere was modified to plant at a 21 inch row spacing and at an average of 6.5 inches between stands. Boyer oats were disc drilled. Individual plot size varied from 2 to 5 acres.

Herbicides: For the corn hybrids, weeds were controlled once with Roundup at 0.67 L/acre. For Proso millet, forage sorghum, Boyer oat and Cowboy barley, 2,4-D amine was used. A section of the Proso millet plots was missed during spraying. Also, spraying didn’t seem to be very effective on Proso millet, forage sorghum and Cowboy barley probably because spraying may have been a bit late for those crops.

Measurements: For all crops, forage yield & feed value were determined at the different stages of growth (Table 1). Crop forage preference observation (across all plots) was done as the cows were allowed into the trial site. The DM yields from forage sorghum and Proso millet is not presented here because of weed invasion in their plots. Also DM yield of turnips is not available because of the high seeding rate, which resulted from the seeder used. But forage samples from these crops were analyzed for feed nutritive value, so only the feed tests results are available for those crops.

For the sole Tillage Radish® plot and Tillage Radish® + Cowboy barley plot, soil nutrient changes, soil compaction and water infiltration will be monitored in the spring of 2013.

The trial site will be grazed by 100 cows and 5 acres will be allocated at a time.

Results and Discussion

Dry Matter (DM) Yield

The forage DM was significantly higher for corn hybrids 2219RR and Fusion RR (except for whole Tillage Radish® plant) than the other crops (including the Tillage Radish®—Cowboy barley intercrop, Table 1). The DM from corn hybrid Edge R was significantly lower than the DM of the two other corn hybrids by 3339 to 4197 lb DM/ac.

Forage Feed Value

With the exception of Cowboy barley, Proso millet and Tillage Radish® (leaf & stem), the crude protein (CP) content of tested crops was generally below 10%. The forage CP was highest for Proso millet (11% CP) and lowest for corn hybrid Edge R (5.14% CP). Generally, all the 3 corn hybrids had lower than 7% CP. Of the tested crop types and the intercrop, only 3 crops (Cowboy barley, Proso millet and Tillage Radish® leaf + stem) had sufficient amount of protein to meet the protein requirements of pregnant and lactating beef cows. The Tillage Radish® —Cowboy barley intercrop was sufficient only for the protein requirements of cows in the mid to late pregnancy stage. Whole Tillage Radish® (leaf, stem and root), turnips and Boyer oat were only sufficient for cows which are in the mid pregnancy stage. Forage sorghum and the 3 corn hybrids (Fusion RR, 2219RR and Edge R) did not have adequate amounts of protein needed by pregnant or lactating cows. Therefore, cows grazing the forage sorghum and corn plots will require some form of protein supplementation using either protein block or a good alfalfa or any other legume hay with high CP.

Both Tillage Radish® (leaf + stem) and turnips had >2.00% Ca content, while other crops had values varying from 0.11 to 1.49% Ca content. The forage Ca content was very low for the 3 corn hybrids. Cowboy barley, Tillage Radish® and turnips all had adequate amounts of Ca required for growing and finishing cattle (0.31% Ca), dry cows (0.18% Ca) and lactating cows (0.27% Ca). Both forage sorghum and Boyer oat were only sufficient for dry cows and lactating cows. But corn hybrid Edge R did not have sufficient Ca% for any of the classes of beef cattle, while both 2219RR and Fusion RR corn hybrids were only able to meet the Ca requirements of pregnant dry cows.

The forage P content varied from 0.20% for both Fusion RR and 2219RR corn to 0.44% for whole Tillage Radish® plant. Forage sorghum, whole Tillage Radish® , Tillage Radish® - cowboy barley intercrop, and turnips all met and even far exceeded the P requirements of growing and finishing cows (0.21% P), dry pregnant (0.16% P) and lactating (0.26% P) cows. Generally, all crops had sufficient amount of P required by pregnant cows.

Except for Cowboy barley, Boyer oat and 2219RR corn, all the cereals tested in this trial were much higher in P than Ca; therefore, suggesting the need for feed tests to be carried out in order to address any short fall in Ca content of cereals for greenfeed, swath grazing or even standing corn. The Ca to P ratio (Ca:P) for a mature beef cow should be within the range of 2:1 and 7:1, assuming actual required grams of each are adequate. In the present trial, whole Tillage Radish® (with root), Tillage Radish® —cowboy barley intercrop and turnips were all within these range. But Tillage Radish® leaf + stem (no root) far exceeded the 2:1 and 7:1 Ca to P ratio. Other crops fell below the required Ca:P for a mature beef cattle. Ratios outside the 2:1 and 7:1 range need to be addressed using feed blends or commercial minerals.

The soil at the site before the trial was not deficient in soil nutrients and we also applied fertilizer following fertilizer recommendations in order to balance nutrients. Herbicides were sprayed once to control weeds. With this level of management, the 3 corn hybrids and forage sorghum still had much lower levels of CP, Ca and P contents as well as the resulting Ca:P than the other crops tested. What is responsible for this is difficult to say. However, the low levels of these feed value indicators could be attributed to the nature and type of the soil (gumbo) at the trial site. Compaction has been shown to affect nutrient uptake and may actually induce nutrient deficiencies, which in this trial was reflected in the feed value of the corn hybrids and forage sorghum.

The individual crops as well as the Tillage Radish® -Cowboy barley intercrop, all had adequate amount of energy (% TDN on DM basis) for cows in mid and late pregnancy stages, which respectively require 55 and 60% TDN.

Observations on the Growth Pattern of Tillage Radish®

Based on the type of soil at the site, which is often referred to as ‘gumbo’, we observed that the roots of the Tillage Radish® plant were unable to penetrate the layer of compacted soil. In response, they spread out horizontally or sideways from about 3 inches soil depth. Most of them therefore exhibited stunted root growth probably due to limited access to soil moisture and nutrients.

Future Plan on Tillage Radish®

One of our objectives is to examine the roles of Tillage Radish® in soil fertility and soil physical improvement in compacted soils. In 2013, Boyer oat will be seeded on the plots which had Tillage Radish® , Tillage Radish® –Cowboy barley intercrop and Cowboy barley (check). This will enable us to carry out soil compaction studies, water infiltration, soil nutrients benefit (from previous plots with Tillage Radish® ), and forage yield and feed value. From the present study using the Tillage Radish® root DM yield (2570m lb/ac) and N content (% CP/6.26 = 1.09%N), we estimated that the Tillage Radish® root contained at least 2808 lb N that should be available in the soil for the next crop. Tillage Radish® will continue to be seeded at the site for the purpose of reducing soil compaction.

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