Authors: Johanna Murray & Dr Akim Omokanye
Research Coordinator: Dr. Akim Omokanye
Location: Fairview Research Farm
From: Peace Country Beef & Forage Association 2020 Annual Report
Several annual forage-type crops are included in cocktail mixtures for livestock production in Alberta. Some of these annual forage-type crops are new to producers. Because of the limited information on their adaptation and agronomic performance in the Peace Country, and elsewhere in Alberta, selected non-conventional annual forage-type crops are being tested for their potential for forage production and nutritional suitability for livestock production. For producers, the selection of annual crops for cocktail cover crop mixes can be a complex process. Ideally, a cocktail for silage or grazing should include species that compliment each other and provide a more complete ration for livestock. Selecting crop species and mixtures with superior production and tonnage can make production more efficient, while selecting species based on nutrition can decrease required supplementation during winter feeding. It is anticipated that some of the non-conventional annual forage-type crops will have high forage production and feed quality that is greater or comparable with traditional annual crops such as oats, barley, or triticale for forage production, and can therefore be included in cocktail mixtures or grown as monocrops for grazing (swath or annual pasture), greenfeed, or silage.
This trial examined multiple annual crop types including 6 brassica varieties, 3 forbs, 6 warm season cereals, 6 cool-season cereals, and 3 cool season grasses. The crops were tested for performance at the Fairview Research Farm, and analyzed for dry matter yield and forage quality.
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. 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 was 13.2% (0-5 cm soil depth), while surface spring soil temperature at seeding was 9.5°C from 0-5 cm soil depth.
Experimental Design: randomized complete block design in 4 replications.
Treatments: the following crops were tested as alternative forage crops:
Seeding Date was May 29.
Spraying: Pre-emergent (StartUp glyphosate + LI surfactant); In-crop (Prestige XL at 0.71 L/acre) for the cereals and grasses. Hand weeding was carried out on brassicas and forbs.
Results and Implications:
The forage moisture content at harvest was significantly influenced by plants examined. At harvest, both warm-season and cool-season grasses (Table 2), and forbs (Table 1) generally had less than 80% moisture content. Except for vivant forage radish, brassicas were mostly moister (>80%) than other plant species tested. The high moisture content observed for some plants, particularly the brassicas, would make preservation as a hay crop impractical in this region, which has a very small window of opportunity to dry down harvested crops in early fall. Low DM content and fibre in most crops (as indicated by high moisture content) may negatively affect livestock performance unless roughage (hay) is provided, because fibre is needed to stimulate rumination, chewing, and saliva production. Thus forage brassicas would be best suited for direct grazing (swath or standing) or silage when grown in cocktail mixtures. In general, both annual ryegrasses (Tetra brand and Elunaria) were drier (55-60%) at harvest than other plants tested.
Forage Dry Matter (DM) Yield (Tables 1 and 2)
In general, the different plant types impacted forage DM yield. The forage DM yield ranged from 359 lb/acre for chicory to 8555 lb/acre for AB Advantage barley. In general, the cool-season crops produced most of the highest yields in this trial with the exception of white proso millet (6900 lb/acre) and German millet (4879 lb/acre). The two barley varieties that have been used as controls in this trial, AB Advantage (8555 lb/acre) and AB Cattlelac (7885 lb/acre) produced the highest yields in this study. Next to the 2 barley varieties was white proso millet (6900 lb/acre), followed by Tetra Brand Annual Ryegrass with a forage DM yield of 6107 lb/acre.
Overall, white proso millet (6900 lb/acre) ranked third in this trial in terms of forage DM yield, outperforming the other warm-season cereals by as much as 4000 lb/acre. Among the warm season grasses, German Millet (4879 lb/acre) and NS Sorghum Sudan grass (4062 lb/acre) produced the next highest yield. As observed in our previous studies, Pearl millet (2623 lb/acre) rarely performs well in the Peace Country and produced the lowest yield of all the warm season cereals.
The two lowest producing cool season crops were KWS Bono Gatano hybrid fall Rye (2660 lb/acre) and Brassetto hybrid Rye (2221 lb/acre). The forbs tested in this trial did not produce much dry matter. Of the three forbs that were tested, Phacelia produced the highest DM yield (2508 lb/acre), while Chicory (359 lb/acre) and Plantain (986 lb/acre) both produced less than 1000 lb/acre of dry matter.
Forage Quality (Tables 1 and 2)
Crude Protein (CP): the plants tested had great impact on forage CP. Overall, the CP values in this trial ranged from 25.9% CP (Malwira Forage Turnip) to 11.3% CP (AB Advantage barley, AB Cattlelac barley).
The highest CP values from cool season cereals and grasses were from KWS Bono Rye (18.4%CP) and AAC Wildfire winter wheat (18.3 %CP) followed by the other Rye varieties. The two barley varieties only yielded 11.3% CP, which is still sufficient for a dry beef cow. For the warm season cereals, Pearl Millet had 20% CP, the highest value for the warm season crops. However, when considering that it had significantly less dry matter yield than the other warm season crops, this may be caused by concentration in less plant matter. The lowest CP from warm season cereals was the white proso millet (14.8 %CP). However, all warm season crops did contain sufficient protein to meet the requirements of all classes of cattle.
Many of the highest CP values are found in the brassica varieties, the highest two being Malwira forage turnip (25.9%CP) and Hercules turnip (25.8% CP). The lowest values came from the two radish varieties, Vivant (14.8%CP) and Double Max (14.1%CP).
Energy: energy levels significantly varied from Malwira Forage Turnip (71.3%TDN) to Phacelia (58%TDN).
Most of the cool season crops tested could meet the TDN requirements of lactating beef cattle with the exceptions of KWS Bono Rye (61.2%) and Elunaria Ryegrass (64.5%). The highest TDN % in the cool season crops came from the AAC Wildfire (69.3% TDN) which almost meets the 70% TDN required by growing calves. The TDN values for the warm season crops were all within 4 points of each other. The highest was again, from the lowest DM yield – Pearl Millet (68.8% TDN) with the second highest coming from NS Drystalk sorghum and German millet which both produced 67.3% TDN. The lowest TDN was produced by white proso millet (64.5). Thus with the exception of white proso millet, every warm season crop tested here produced sufficient TDN for lactating cows, but none met the requirement of growing calves. For brassicas and forbs, the lowest TDN was the phacelia which yielded 58% TDN followed by Plantain and Vivant forage radish, both of which yielded 61.2%. The only crops in this trial that met the requirement of growing calves were Malwira forage turnip (73%) and Hercules turnip (71%) However, with the exception of the three lowest TDN, (Vivant, Plantain, and phacelia) all other brassicas and chicory met the requirements of lactating beef cattle.
Minerals: Calcium (Ca) levels in this trial varied from 3.19% (Hercules turnip) to 0.31% (AB Cattlelac barley). The brassicas and forbs contained notably higher Ca than the cereals and grasses. All the tested crops had sufficient Ca to meet the requirements of dry gestating cattle and growing or finishing calves. However, approximately half of the tested crops fail to meet the Ca requirement of lactating beef cattle, meaning supplementation would be required.
Forage phosphorus (P) varied from 0.44 to 0.12% for the tested crops. The cool season grasses had some of the lowest (0.12% for AB Cattlelac barley). While the forbs contained similar average phosphorus to the grasses and cereals, the brassicas again contained higher phosphorus levels than other crops. All the crops in this trial met the P requirements of a dry beef cow, except for the two barley varieties (AB Advantage and AB Cattlelac) and the three ryegrasses (Tetra Brand, Elunaria, and Firkin). Only the forage turnips, forage brassica, and AAC Wildfire winter wheat were able to meet the phosphorus requirements of a lactating beef cow, which is 0.26% P. All the tested crops met the potassium, and iron requirements of all classes of beef cattle, but were deficient in copper, and manganese. AB Cattlelac is the only crop tested that was deficient in magnesium and sulphur.
When feeding beef cattle – recall that many minerals must be fed in the correct ratios in order for cattle to absorb them. With high variability in this trial, even if a crop meets the minimum requirements for most minerals, it may not be absorbed by the cattle. Therefore, it’s recommended that free-choice mineral with guaranteed analysis be provided when feeding any of the crops in this trial.
It is notable in this trial that many of the highest yielding crops had lower nutritional numbers than several lower yielding crops. For example, both barley varieties produced more than 7800 lb/acre but contained the least protein of any crop. This may be caused by a number of factors such as dilution due to high moisture through the growing season, or time of harvest. This disparity of yield and nutrition should be considered when making feed as well.