Authors: Johanna Murray & Dr Akim Omokanye
Research Coordinator: Dr. Akim Omokanye
Location: Fairview Research Farm
From: Peace Country Beef & Forage Association 2020 Annual Report
The most common cereals used for forage are oats, barley, and spring triticale. Winter cereals are used by many producers to produce high-quality silage for the winter feeding of beef cattle. Mixtures of winter rye or winter triticale with spring oats can be harvested for silage, with the fall regrowth providing a productive, quality pasture for heifers in the fall, when perennial pastures are going into dormancy and decreasing in productivity. In recent years, though many new varieties of cereals have been released, these varieties have not been tested with different crop types and in spring/winter mixes. Data regarding the performance of these new varieties within mixtures and an understanding of the regional adaptability of new varieties will be key for Alberta producers to make the most economic decisions for their operations. PCBFA is taking part in a study to look at different spring crop types (barley, oats, and triticale) and their mixtures with winter cereals as part of a broader provincial study.
Objective
To identify forage and nutritional differences between annual crop species and mixtures for livestock production.
Methods
The study was carried out at Fairview Research Farm (NW-5-82-W6M) in RR #35, MD of Fairview.
The previous crop at this site was an alfalfa hay crop for several years until it was ploughed in the fall of 2018. The site was chemical fallowed in 2019.
In 2020, the site was tilled with a cultivator and harrowed before seeding.
Soil analysis carried out in the fall of 2018 from 0-6” soil depth showed an organic content of 8.2%, a pH of 6.2, and an electrical conductivity of 0.21 ds/m. The soil had 10 lbs N/acre, 14 lbs P/acre and 485 lbs K/acre as well as 9 lbs S/acre.
Surface spring soil moisture at seeding: 13.2% (0-5 cm soil depth). Surface spring soil temperature at seeding was 9.5°C (0-5 cm soil depth).
Experimental Design: randomized complete block design in 4 replications.
Monocrops of CDC Austenson barley, CDC Baler oats, and Taza spring triticale have been included for determining forage yield or quality advantage of the mixtures. The treatments were made up of 3 spring cereal monocrops and 12 spring/winter cereal mixtures as listed below:
1. CDC Austenson barley monocrop
2. CDC Baler oat monocrop
3. Taza spring triticale monocrop
4. AAC Wildfire winter wheat/barley mix
5. AAC Wildfire winter wheat//oat mix
6. AAC Wildfire winter wheat/spring triticale mix
7. Prima fall rye/oat mix
8. Prima fall rye/barley mix
9. Prima fall rye/spring triticale mix
10. Bobcat winter triticale/oat mix
11. Bobcat winter triticale/barley mix
12. Bobcat winter triticale/spring triticale mix
Seeding rates for the monocrops were: 27.8 plants/sq.ft for barley and oats, and 34.3 plants/sq.ft for triticale. The mixtures were seeded at 75% of their respective monocrop seeding rates.
Seeding date was on May 29, 2020. 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 applied (lbs/acre actual) was applied at: 37 N + 35 P2O5 + 0 K2O + 13 S
Spraying: Pre-emergent (StartUp glyphosate + LI surfactant); In-crop (Prestige XL at 0.71 L/acre).
Harvesting was carried out between August 18 and September 3.
Results and Implications
Dry Matter (DM) Yield
The forage DM yield was impacted by the cropping treatments tested (Table 1). Of the mixtures and monocrops in this trial, CDC Austenson barley monocrop (9,455 lb/acre) had the highest yield, followed by the mixes of Bobcat winter triticale/barley (8,548 lb/acre), Prima fall rye/barley (8,087 lb/acre) and the CDC Baler oat monocrop (8,076 lb/acre). The order of forage DM yield for the monocrops was: CDC Austenson barley > CDC Baler oat > Taza triticale. Both Prima fall rye/barley mix and Bobcat winter triticale/barley mix were the only mixtures which had 8000 lbs or more forage DM yield. Other mixtures had less forage DM yield.
Prima is a tall, medium maturing fall rye, that is suitable for grain, silage, grazing, and cover crop use. Bobcat winter (or fall) triticale is a forage triticale that has reduced awn expression. It can be used for grazing, silage, greenfeed, and now recently as a base for cover crop cocktail mixes in some places.
Forage Quality
The different crop mixtures/monocrops had significant impact on forage crude protein (CP) (Table 1). The CP was highest in the mix of AAC Wildfire winter wheat/oats (11.1%CP). The monocrops and mixtures generally had 9% CP or more, an indication that the mixtures and monocrops have been able to meet the CP requirement of lactating beef cattle. Both AAC Wildfire winter wheat/oat mix and Prima fall rye/spring triticale mix seemed to have sufficient protein for dry gestating cows (11% CP), while the other monocrops and mixtures did not.
Detergent Fibres and Energy
Forage detergent fibre analysis (ADF and NDF), TDN, and other forms of energy (NEL, NEG and NEM) all varied significantly in this trial and their values are presented in Table 2. The main form of energy (TDN) in this trial ranged from 67.9% TDN in the AAC Wildfire winter wheat/oat mix to 59.9% TDN (Bobcat winter triticale/barley mix). All mixes and monocrops provided sufficient TDN for dry gestating beef cattle, which require 55% TDN in mid– and 60% TDN in late-pregnancy. However, only half of the mixes and monocrops would provide adequate TDN for lactating beef cattle that need 65% TDN or growing/finishing cattle (65-70% TDN).
The most likely highly digestible mix was AAC Wildfire/CDC Baler with 35% ADF and 48.7% NDF. While the highest detergent fibre content was in the Bobcat/Austenson mix at 41.9% ADF and 62.5% NDF. Neither level is likely to cause issues, however, lower NDF levels may increase feed intake.
Minerals
Forage Ca, P, K, Mg, and Na have been significantly impacted by cereal monocrops and mixtures. AAC Wildfire winter wheat/oat mix had the highest Ca and this was followed by Bobcat winter triticale/spring triticale mix with 0.71% Ca (Table 3). Monocrop oats and spring triticale, as well as their mixtures with winter cereals, showed higher Ca than monocrop barley and winter cereal/barley mixtures. The requirements for Ca by pregnant beef cattle is 0.18% and at nursing is 0.58% according to NASEM (2016). This shows that all treatments studied here would provide sufficient Ca for mature beef cattle, as well as growing and finishing calves that require 0.31% Ca.
Monocrop barley had higher P and K than monocrop oats and triticale (Table 3). More so, the presence of barley in the mixtures seemed to have improved forage P and K content more than when oats or triticale was in the mixture. All treatments have been able to adequately meet the P requirement of dry gestating beef cows (0.16% P), but were generally lower than the 0.26% P that is required by lactating beef cattle. The K requirements by all categories of beef cattle (0.6-0.7% K) have been met by all treatments tested here.
Oats by itself (monocrop oats) and in mixtures with winter cereals appeared to have greater forage Mg and Na than monocrop barley and triticale and their respective mixtures (Table 3). The requirements of Mg by beef cattle have been met by all treatments, but not for Na as Na levels were low for all crops. All treatments fell short of the suggested Na levels for mature beef cattle.
Interestingly the AAC Wildfire winter wheat/oat and Bobcat winter triticale/spring triticale mixtures, which had the highest levels of Ca and Mg showed the lowest levels of P and K. In light of this variation, and the inability of any particular treatment to meet the Na needs of beef cattle, it is important to keep in mind that many minerals must be provided in the correct proportions to each other in order to be absorbed by cattle. Therefore, it’s recommended that free-choice minerals with guaranteed analysis be provided when feeding any of the crops in this trial.
Conclusion
The Peace Country region has a shorter growing season than other parts of Alberta, so extension of pasture productivity during the late summer and fall is especially important and can be accomplished with annual cereals. By intercropping winter cereals with spring cereals producers may be able to improve forage quality and extend fall grazing. In this study, monocrop barley did have higher forage DM yield than other monocrops and mixtures, and mixing barley with winter cereals (except for AAC Wildfire winter wheat) provided some forage DM yield advantage over oats or spring triticale mixed with winter cereals. It’s recommended that free choice mineral with guaranteed analysis be provided when feeding any of the crops in this trial to take care of inadequacies of some minerals.