Research Coordinator: Dr. Akim Omokanye
Location: Fairview Research Farm
From: Peace Country Beef & Forage Association 2019 Annual Report
Oats are one of the cool-season cereals widely grown for livestock production in the Peace River region. The economic value of cereal forage for feeding beef cattle is dependent on both its yield and feeding value (i.e., crude protein, minerals, detergent fiber, energy, digestibility and animal performance). PCBFA continues to carry out field trials for the purpose of identifying oat varieties that have better forage production for livestock producers in the Peace. As part of the Regional Silage Trials (RSTs), several new oat varieties as they become available are tested along with older ones for adaption, forage yield and quality. The RSTs generate and provide scientifically sound oat variety performance information to livestock producers, industry and extension specialists. In addition to the findings of the oat variety trial from Fairview Research Farm being presented here, the results from the RSTs across the different trial sites in the province will also be reported in the Alberta Seed Guide (www.seed.ab.ca).
Objective
To identify oat varieties with better forage yield and quality for livestock production.
Methods
Experimental Site: Fairview Research Farm (NW-5-82-3-W6M) on RR #35, MD of Fairview.
Previous Crop: The previous crop at the site was an alfalfa hay crop for several years until the Fall of 2017. This was unseeded (chemical fallow) in 2018.
Land Preparation: In the fall of 2018, the site was sprayed with Roundup at 1.0 L/acre (to kill the existing alfalfa-dominated vegetation) and plowed. The site was disced & harrowed in the spring of 2019.
Soil analysis completed in the Fall of 2018 from the soil depth of 0-6” showed an organic matter content of 8.2%, pH of 6.2 and electrical conductivity of 0.21 ds/m. The soil test reports showed 10 lbs N/acre, 14 lbs P/acre and 485 lbs K/acre as well as 9 lb S/acre.
Spring soil moisture at seeding: 12.4% (0-5 cm soil depth) and 14.1% (0-20 cm soil depth).
Spring soil temperature a Seeding: 9.19°C (0-5 cm soil depth) and 7.79°C (0-20 cm soil depth).
Experimental Design: Randomized Complete Block Design with 4 replications.
Treatments: The following 13 oat varieties were tested:
1. AC Juniper 6. CDC Nasser 10. CDC Seabiscuit
2. CDC SO-1 7. CDC Baler 11. oRe 3542M
3. CDC Haymaker 8. AC Morgan 12. Murphy
4. Oravena 9. Kongsore 13. Arborg
5. oRe 3541M
Seeding Rate: A plant population of 300 plants/m2 (27.8 plants/ft2) was used.
The seeding date was May 23.
Seeding Method: The seeds were sown using a Fabro plot drill equipped with disc-type openers on 9” row spacing. Six rows that were 8 m long were sown per plot. Seeding depth was 0.75”.
Fertility for an average oats yield (actual lbs/acre) was applied at: 89 N + 39 P + 0 K + 13 S. No K was applied as the soil test reports showed optimum levels of K for oats production for the year.
Spraying: Pre-emergent herbicide with StartUp (Glyphosate, 540 grams acid equivalent per litre, present as potassium salt) was applied at 0.67 L/acre. StartUp is a water soluble herbicide for non-selective weed control. In-crop herbicide application was with Prestige A (170 mL/acre) + Prestige B (800 mL/acre).
Harvesting for forage dry matter (DM) yield determination was done on August 15 when the oats were at the milk stage. Forage samples were shipped to A & L laboratory, Ontario for forage quality determination. Plant height was take a day before the varieties were harvested. Notes were also taken on plant lodging a day before harvest.
Rainfall received from seeding to forage harvest for the oats was 167.1 mm (or 6.58”), which was comparable to the long-term average for the same period of 168.7 mm (6.64”).
Results and Implications
Plant Growth and Forage Dry Matter Yield
Murphy oats was the tallest of the varieties tested, followed by CDC Baler, CDC Haymaker, Oravena and AC Morgan in that order (Table 1). Ore3541M was not as tall as other varieties tested. Some lodging was observed for Murphy oats (rated 2 out of a 10-point scale where 0 represents perfect standability and 9 equal to severe lodging). No lodging was observed for other oats varieties.
The forage dry matter (DM) yield was highest for Ore3541M oats (with about 5 tons DM/acre) (Table 1). The oats tested generally produced >3.5 tons DM/acre. Surprisingly, CDC Haymaker oats, known for its high forage yield did not produce exceptional yield this year. What is responsible for the slightly lower forage DM yield for CDC Haymaker oats than a few oats tested this year is difficult to explain.
Forage Quality
The forage crude protein (CP) values were statistically similar for all oats tested. The forage CP varied from 10.0 - 12.4% (Table 1). With a minimum of 10% CP obtained here, this shows that all oats were able to meet the 10% CP needed by a dry gestating cow.
In terms of energy, the forage total digestible nutrients (TDN), as well as other forms of energy (NEL, NEG and NEM), were not statistically affected by oat varieties tested. The forage TDN for the oats varied from 64.5 - 67.2% (Table 2). The forage NEL, NEG and NEM varied from 1.35 - 1.43 Mcal/kg, 0.70-0.82Mcal/kg and 1.42 - 1.54 Mcal/kg, respectively (Table 2).
Using %TDN as a measure of energy, the Rule of Thumb is 55-60-65. This rule says that for a mature beef cow to maintain her body condition score (BCS) through the winter, the ration must have a TDN energy reading of 55% in mid pregnancy, 60% in late pregnancy and 65% after calving. With the ability of all oats tested in this study to produce 65% TDN (and slightly more in a few cases), this shows that all oats have been able to meet the energy requirements of different categories of mature beef cattle. The recommended NEM for a dry gestating beef cow is 0.97 - 1.10 Mcal/kg and for a lactating beef cow it is 1.19 - 1.28 Mcal/kg. With values of 1.42 - 1.54 Mcal NEM/kg obtained from the present study (Table 2), it shows that all oats have exceeded the energy requirements for maintenance during pregnancy and lactation.
The forage macro and trace minerals measured and reported here were mostly similar for all oats tested (Table 3). On the other hand, both forage Na (macro mineral) and Mn (trace mineral) were influenced by oat varieties investigated. Both Kongsore and Arborg varieties had significantly higher forage Na than other oats, while CDC Baler produced higher forage Mn than other oats.
All oats tested produced enough Ca, P and Mg for a dry gestating beef cow, but not for lactating beef cow. However, the required K, S, Fe, Zn and Mn by a lactating beef cow were adequately met and even far exceeded in most cases. Most oats had enough Na for mature beef cattle. The forage Cu from all oat varieties were not sufficient for mature beef cattle, which require 10 ppm Cu.
Conclusion
In this test, the top 3 forage DM yielders are Ore3541M, Oravena and AC Morgan. These oats also grew taller than the other oat varieties tested in this trial. The forage CP varied from 10.0 - 12.4% CP and the oats were therefore generally considered adequate in protein for a dry gestating beef cow. Most oats met the 11% CP required by a lactating beef cow. The oats produced similar %TDN and were generally considered to be sufficient in energy for mature beef cattle. The oat varieties tested here were all short of meeting the Cu requirements of all categories of beef cows. Though most of the minerals measured here would be considered adequate for a dry gestating beef cow, free choice minerals (with guaranteed mineral analysis) would still be ideal when feeding any of these oats to beef cattle to address any shortfall, particularly those of Cu and Zn.