Project Site: Bill Fevang's Farm - High Prairie
Research Program Manager: Dr. Akim Omokanye
From: Peace Country Beef & Forage Association 2018 Annual Report
In the Peace Country, several new or alternative annual forage crops are now available to producers, however, evaluation of their adaptation and nutritional suitability for beef cattle are still needed. Preliminary trials and demonstrations done by PCBFA in the last few years have shown that many annual crops are suitable for inclusion in cocktail mixtures for forage production (grazing, silage or greenfeed) and to improve soil health. This year, we seeded a variety of annual forage-type legumes to evaluate for forage production (yield) and quality. The information provided from this trial is intended to familiarize livestock producers with the variety of annual forage legume feed options available.
Methods
The study site was at Bill Fevang’s farm in High Prairie. The site had canola the year before and it was sprayed with a pre-seed burnoff before seeding the cocktails in 2018. Soil tests from 0-6” showed an organic matter of 10.3%, a pH of 5.9, and an electrical conductivity of 1.0 dS/m. The soil had 27 lbs N/acre, 23 lbs P/ac, 496 lbs K/ac and 19 lbs S/ac. The annual forage legume types tested (8) and their seeding rates are provided below:
1. CDC Meadow peas (check) seeded @ 8.33 plants (155 lbs/acre)
2. Subterranean clover seeded @ 20 lbs/acre
3. Winner brand berseem clover seeded @ 15 lbs/acre
4. Laser brand Persian clover seeded @ 5 lbs/acre
5. Serradella seeded @ 3 lbs/acre
6. HO Crimson clover seeded @ 15 lbs/acre
7. Ebena common vetch seeded @ 20 lbs/acre
8. Lupins seeded @ 60 lbs/acre
· Seeding date: June 7
· Legumes were inoculated at seeding
· We applied only 50 P lbs/acre + 13 S lbs/acre.
· An in-crop herbicide weed control was done with Basagran Forte @ 0.8 L/acre
· Forage harvest date was on August 20. For each legume plot, the above ground biomass was harvested from the 4 inner rows, in a strip 2 m long, and weighed fresh. Approximately two 0.7 kg subsamples of freshly harvested material per legume was shipped to A&L Canada Laboratories Inc., London, Ontario for determination of forage nutritive value (% DM basis).
Results
Forage Dry Matter (DM) Yield
The forage DM yield was similar for legumes but significantly different between some legumes. Meadow peas had the highest forage DM yield with 5841 Ibs DM/acre, followed by HO Crimson clover (4828 lbs DM/acre), Lupins (4807 lbs DM/acre) and Laser brand Persian clover (3902 lbs DM/acre) in that order (Table 1). Subterranean clover produced a significantly lower forage DM yield than other legumes. Subterranean clover was the only legume that produced less than 1.5 tons DM/acre.
Forage Quality (Table 1)
Crude Protein (CP): The forage CP values of the legumes tested varied from 12% CP for HO Crimosn Clover to about 20% CP for serra della. All legumes had enough CP for a mature beef cow. Most legumes can be used as good protein supplement when feeding other feeds that have low CP.
Energy: The total digestible nutrients (TDN) values were higher with Ebena common vetch and Laser brand Persian clover, both of which had > 65% TDN. Both HO Crimson clover and Meadow peas had lower forage TDN values (54.6-55.5%). Four of the legumes (Laser brand Persian clover, Serra della, Ebena common vetch and Lupins) had >60% TDN, and this would be considered adequate for a dry gestating beef cow.
In terms of net energy requirements for maintenance (NEM), all legumes exceeded the 1.08-2.29 Mcal/kg NEM for growing and finishing calves, 0.97-1.10 Mcal/Kg NEM for dry gestating beef cows, and 1.19-1.28 Mcal/kg NEM for lactating beef cows. All legumes, except for HO crimson clover, were within the 0.53-1.37 Mcal/kg net energy for gain (NEG) requirements by growing and finishing beef calves.
Minerals: Macro and trace mineral levels were significantly different between legumes.
Except for forage P, Ebena common vetch seemed to have higher forage macro nutrients than other legumes. All Legumes met the required Ca, Mg, K, and S for young and mature beef, but only subterranean clover, Serra della and Ebena common vetch met the required 0.26% P for a lactating beef cow. Both HO crimson clover and Lupins fell short of meeting the required P for both young and mature beef cattle. Winner brand berseem clover had a significantly higher forage Na content than other legumes. Except for Meadow peas, all legumes meet the required forage Na for mature and young beef cattle.
For the trace minerals, Subterranean clover and winter brand berseem clover had significantly higher Cu levels (> 15ppm) than all other legumes (7.55-11.4 ppm). Most legumes did not meet the required 10 ppm of Cu for all categories of beef cattle, but Subterranean clover, winter brand berseem and Serra della did meet the required amount of Cu for young and mature beef cattle. All legumes exceeded the required Fe level for cattle in all psychological stages. The forage Mn content was significantly high for Lupins (195 ppm Mn). Forage Zn levels were significantly different across legume varieties, with the highest Zn level coming from Serra della (106 ppm), followed by Lupins with 99.3 ppm, and then Meadow peas with 78.6 ppm. All legume varieties had more than enough Zn for mature and young beef cattle.
Detergent Fibres: The forage acid detergent fibre (ADF) and neutral detergent fibre (NDF) were significantly lower for Ebena common vetch than the other legumes. This shows the potential for greater digestibility and intake for Ebena common vetch.
Conclusion
Meadow peas (check) had significantly the highest forage DM yield than all alternative forage-type legumes. For the alternative forage type legumes, HO Crimson clover and Lupins particularly produced higher forage DM yields than others. Subterranean clover, because of its growth pattern, had a significantly lower DM yield than all other legumes tested. Meadow peas compared well in most cases with most alternative forage-type legumes, but Ebena common vetch appeared to have higher energy levels, mineral contents and better digestibility than all other legumes.