Regional Silage Variety Trials: 4. Pea-Cereal Mixtures

Trial Site: Fairview Research Farm

Research Coordinator: Dr. Akim Omokanye

From: Peace Country Beef & Forage Association 2017 Annual Report


Planting and growing two crops simultaneously on the same field, particularly growing of legumes with cereals, is known to offer scope for developing energy-efficient cropping systems and sustainable agriculture. Peas are usually included in mixes to improve the quality of the feed. Pea silage could be 13-18% protein so theoretically a pea/cereal mix should have higher protein than a cereal silage alone, which is usually about 10% protein. In reality however, the potential protein benefits of peas in silage mixtures often are not attained because of the competitive effects of the cereal crop. Pea/cereal mixtures can produce better quality silage than cereals alone, but the success of these intercrops is highly dependent on the seeding rates for both crops, and making sure there are enough peas in the mixture to influence feed quality (for more information, please visit http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq8444). In addition to the report presented here, results from this site and other parts of the province for the pea-cereal mixtures will also be reported in the Alberta Seed Guide (www.seed.ab.ca).


Objective

To compare the performance of intercropping spring oats, barley and triticale with pea varieties for forage yield and feed quality for beef cattle production


Methods

  • Project Site: Fairview Research Farm (NW5-82-3W6) on RR #35, MD of Fairview.

  • Previous crop: Alfalfa for over 10 years before spraying out in 2016 (chemical fallow)

  • Site soil information (0-6” depth): Soil tests done at Exova laboratory (Edmonton) prior to seeding showed pH = 5.8 and soil organic matter = 7.0 %.

  • The field was cultivated (disked and harrowed) before seeding.

  • Experimental Design: Randomized complete block design in 4 replications


Treatments: 3 cereals (1 barley, 1 oat & 1 spring triticale) & 2 pea varieties (CDC Meadow & CDC Horizon) were used in the following pea-cereal mixtures:

1. AAC Austenson barley (monocrop)

2. Taza triticale (monocrop)

3. CDC Baler oat (monocrop)

4. CDC Austenson barley/CDC Leroy pea

5. CDC Austenson barley/CDC Meadow pea

6. Taza triticale/CDC Leroy pea

7. Taza triticale/CDC Meadow pea

8. CDC Baler oat/CDC Leroy pea

9. CDC Baler oat/CDC Meadow pea


Seeding Date & Rate: seeding was done on May 30 at the following rates:

1. CDC Austenson barley- 300 plants/m2 (27.8 plants/ft2 )

2. CDC Baler oat - 300 plants/m2 (27.8 plants/ft2 )

3. Taza triticale - 370 plants/m2 (34.3 plants/ft2 )

4. Pea-cereal mixtures - 75% of pea seeding rate + 50% of cereal seeding rate


Seeding method: 6-row Fabro plot drill with 9” row spacing


Fertility (actual lbs/acre):

1. Pea/cereal mixtures - 50 lbs/acre of 11-52-0 for peas

2. Pure cereal stands- 89 N + 50 P + 29 K + 24 S


Plot size: 11.04 m2 (118.8 ft2 )

Spraying: In-crop spraying was done once with Curtail M (800 ml/acre) + Fluroxyoyr (170ml/acre) for the monocrop cereals. Basagran Forte was used on pea/cereal mixtures once.


Measurements

1. Plant height was taken from 5 plants at random for the pure cereal stands and for the cereals and peas in the mixtures just before harvest.

2. Barley and pea/barley mixtures were harvested at the soft-dough stage

3. Oats and pea/oats mixtures were harvested at the milk stage

4. Triticale and pea/triticale mixtures were harvested at the late milk stage


Results and Interpretation

Forage Dry Matter (DM) Yield (Table 1)

The Taza triticale/CDC Meadow pea mixture had higher forage DM yield value (9091 lbs/acre) than the 3 monocrop cereals (6489-7628 lbs/acre) and the other pea-cereal mixtures (5959-8425 lbs/acre). Generally, monocrop triticale and its mixtures with any of the peas (CDC Leroy & CDC Meadow) appeared to have slightly higher forage DM yield than other monocrop cereals and pea/cereal mixtures. Except for CDC Baler/ CDC Leroy mixtures, pea/cereal mixtures which had CDC Leroy peas did not do as well as mixtures which had CDC Meadow peas. Overall, there appeared not to be any significant forage DM yield advantage from pea/cereal mixtures over the monocrop cereals tested here.


Forage Quality (Table 1)

Crude Protein (CP): All monocrop cereals, as well as pea/cereal mixtures, had similar forage CP content, but with Taza/CDC Leroy being slightly higher. All monocrop cereals and their mixtures had adequate CP for a dry gestating beef cow, which requires 7% CP at second-trimester and 9% CP at third-trimester. For a lactating beef cow, which requires 11% CP, only CDC Austenson/CDC Leroy and Taza/CDC Leroy mixtures met the requirement.


Energy: The forage total digestible nutrients (TDN) and other forms of energy [net energy for maintenance (NEM), lactation (NEL) and gain (NEG)] measured here were all higher for monocrop CDC Austenson than other monocrop cereals and all of the mixtures. Except for pure Taza and Taza/CDC Meadow pea mixture, the forage TDN contents obtained here were adequate for a mature beef cow. Also, forage net energy for maintenance (NEM) values obtained for all monocrop cereals and mixtures far exceeded the 1.19-1.28 Mcal/ kg NEM requirements by mature beef cattle.


Minerals: An essential mineral performs specific functions in the body and must be supplied in the diet, but too much of any mineral may be harmful or even dangerous. The forage macro minerals measured in this study were Ca, P, K, Mg, Na and S.


Ca and P are the most abundant minerals in the animal. They are also the ones most often added to ruminant diets. Both are found in the teeth and bones, but calcium is also found in milk. In addition, Ca is necessary for the clotting of blood and the contraction of muscles. Ca works in conjunction with phosphorus and other nutrients to perform numerous biochemical reactions in the body. Phosphorus is required in all biochemical reactions, including the conversion of feed energy into a form utilized by the animal. Animals require a minimum of 1.5 parts Ca for every part of P.


The forage Ca content was highest for Taza/CDC Leroy mixture (0.55 % Ca). Monocrop cereals had lower forage Ca than their respective mixtures. The 2 triticale/pea mixtures seemed to improve forage Ca more than other cereal/pea mixtures. The forage P value was higher for both CDC Austenson/CDC Meadow pea and Taza/CDC Leroy pea mixtures than monocrop cereals and other mixtures. Monocrop Taza triticale appeared to have lower forage P value than its mixtures with peas.

Taza triticale/CDC Leroy had higher forage Mg (0.22% Mg) than other monocrop cereals and mixtures.


Monocrop barley and its mixtures had significantly higher forage Na than other monocrop cereals and their mixtures.


Monocrop Taza triticale had lower forage K, Mg, Na & S than other monocrop barley, oats and pea/cereal mixtures.


Taking into consideration the macro mineral requirements for young and mature beef cattle, only the forage Mg (except monocrop Taza triticale, only for a lactating beef cow) and K requirements of all categories of beef cattle have been met by monocrop cereals and their mixtures. With the exception of monocrop Taza triticale, all monocrop cereals and pea/cereal mixtures had sufficient amounts of forage Ca and P for a dry gestating beef cow. None of the monocrop cereals and their mixtures were able to meet the Ca & P requirements of a lactating beef cow. The forage P values obtained for monocrop cereals and their mixtures were also not adequate for growing and finishing calves.


A young beef calf and a mature beef cow respectively require 0.06-0.08% Na and 0.10% Na. Monocrop barley cereal and its mixtures far exceeded the Na requirements of both young and mature beef cattle. Pure barley cereal fell slightly short of meeting the Na requirements of a mature beef cow, while pea/barley mixtures were only able to meet the 0.06-0.08% Na needed by a dry gestating beef cow. Pure Taza triticale and its mixtures with peas failed to meet the Na requirements of both young and mature beef cattle.


For the trace minerals measured here (Cu, Fe, Zn & Mn), only the barley/CDC Leroy peas mixture appeared to improve forage Cu, Fe, Zn & Mn contents over monocrop barley. Other mixtures did not show any improvements in forage trace minerals over their respective monocrop cereal crops.


None of the monocrop cereals and their mixtures contained the required amount of Cu (10 ppm) for young and mature beef cattle.


Monocrop barley and its mixtures with peas had sufficient forage Fe, Zn and Mn for all categories of beef cattle. Monocrop oats and its mixtures met the requirements for Fe and Zn of different categories of beef cattle. Monocrop oats and its mixtures had enough Mn for growing and finishing calves (20 ppm Zn), but fell short of the 40 ppm Zn needed by mature beef cattle. Monocrop triticale and its mixtures did not meet the 50 ppm Fe and 40 ppm Mn needed by mature beef cattle. Mixtures of Taza triticale and peas however, exceeded the 40 ppm Mn needed by mature beef cattle. Monocrop triticale and its mixtures had adequate forage Zn for all categories of beef cattle.


None of the monocrop cereals and their mixtures were able to meet the macro and trace mineral requirements of any class of beef cattle, so a supplemental mineral program is required.


Trace minerals are only required in very small amounts. Some trace minerals fed in excess amounts may cause a deficiency in others. A slight deficiency or excess trace-minerals may cause a decrease in performance that is hard to pinpoint. Trace minerals can be effectively supplemented in cattle diets by using the proper trace mineralised salt.


Conclusion

The monocrop cereals and mixtures with CDC Leroy peas had lower forage DM yields than the respective oat, barley and triticale mixtures with CDC Meadow peas. The CDC Meadow pea/cereal mixtures consistently had higher forage DM yield than each monocrop cereal type tested. In some cases, intercrops appeared to improve forage crude protein (CP) content over the respective monocrops. The forage energy (%TDN) from monocrop cereals and their mixtures was in most cases adequate for mature beef cattle. Some form of commercial mineral supplement would be required during feeding to beef cattle.

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