Perennial Forage Demonstration in High Prairie: Yield & Feed Value Following Third Year of Cutting

Research Coordinator: Dr. Akim Omokanye

Location: High Prairie Airport (MD of Big Lakes)

From: Peace Country Beef & Forage Association 2013 Annual Report

The forage plots in High Prairie is one of the two PCBFA perennial forage plots established in 2010 in the Peace Region. The site has continued to provide us with necessary data on agronomic adaptation, dry matter (DM) yield and nutritive value for the 32 grass and legume species and varieties seeded in 2010. The PCBFA Annual Reports for 2010, 2011 and 2012 have information regarding seeding, management and some reports on DM yield and quality as well as the selenium contents of selected forage varieties. In 2011, each forage variety was divided into three sections. These sections were cut at different times during the summer months of 2011, 2012 and 2013.

Management and Measurements in 2013

There are 2 separate blocks of grasses and legumes. Varieties used for comparison were: Fleet meadow bromegrass & Carlton smooth bromegrass (grasses); Anik, Peace & Algonquin alfalfa varieties (legumes).

Fertility - Broadcast of 67.5 lbs actual N/acre was done on the entire plot of grasses. No fertilizer application was made on the legume plots.

Weed Control – The grass species plots were sprayed once with Curtail M at the rate of 0.7 L/acre @40L water volume and the legumes also sprayed once with Basagran Forte at the rate of 0.91 L/ac at 45 L water volume. Hand weeding was occasionally done.

Winter Kill - Notes on winter kill were taken early in the spring by assessing crown and root health and any damages done. Plants suffering from winter kill would normally have soft and fibrous crowns.

Plant Growth, Cutting and Recovery Following Cutting Treatments – In 2011, each forage variety plot measuring 2.5m x 17m was divided into three sections. In 2012 and 2013, the first, second and third sections were respectively cut: (1) in first week of June (1 cut only - June only), (2) first week of June & first week of August (2 cuts) and (3) first week of August (1 cut - August only) for DM yield and feed value determination. Forage DM yield estimation was done using two randomly placed 0.5m x 0.5m quadrats in each plot. Following forage sampling with quadrats, a sickle mower was used to cut the remainder of the cut section. Yearly, the 6 top grasses and top 7 legumes were selected based on DM yields, winter hardiness and early spring growth and had their feed quality determined. The following forages from the late cut (August only) were analyzed for selenium content: Tall fescue, Anik alfalfa, Carlton smooth bromegrass, Fleet meadow bromegrass, Algonquin alfalfa, and timothy.

Results and Discussion

DM Yield

Grasses (Figure 1)

When cut in June for the June only cut, only 3 (Kirk crested wheatgrass, AC Goliath crested wheatgrass and AC Rocket hybrid bromegrass) of the 14 grasses had > 1.0 ton forage DM/acre. The 11 other grasses had < 1.0 ton DM/acre.

For the 2-cut system, when cut in June (1st of 2-cut system), DM yield of the top 5 grasses (0.56 - 0.88 ton DM/acre) was in order of: AC Goliath crested wheatgrass > Kirk crested wheatgrass > Carlton smooth bromegrass > Grindstad timothy > Derby timothy. But when cut in August (2nd of 2-cut system), the order of the top 5 grasses in DM yield (0.99 - 1.67 ton DM/acre) was: Palaton reed canary grass > Boreal creeping red fescue > Derby timothy > Climax timothy > AC Knowles hybrid bromegrass. Only 6 of the 14 grasses had total DM (June + August cuts), which equalled or greater than 1.50 ton DM/acre. Total yield for other grasses was lower than 1.5 ton DM/acre for 2013.

When cutting was delayed until August (August only cut), DM yield varied from 0.74 ton/acre for Barolex tall fescue grass to 2.64 ton DM/acre for Palaton reed canary grass. For August only cut, Palaton reed canary grass, Grindstad timothy, Derby timothy, Kirk crested wheatgrass and Climax timothy were the 5 top grasses.

At the High Prairie site, pooled across the cutting treatments, only 4 (Palaton reed canary grass, Kirk crested wheatgrass, Derby timothy and Grindstad timothy) of the 14 grasses had an average DM >1.50 ton DM/acre for the year.

Legumes (Figure 2)

For the early June one cut system, of the 17 legumes at the site, only 4 alfalfa varieties (AC Blue, Spredor 4, Multi 5301 and Matrix) had >2.50 ton DM/acre. Other legume varieties had lower than 2.50 ton DM/acre. For the early June only cut, AC Blue J alfalfa had the highest DM yield (3.41 ton DM/acre) and closely followed by Matrix alfalfa (3.22 ton DM/acre).

For the 2-cut system (early June and early August), when cut in early June (1st of 2-cut system), DM yield was highest for Anik alfalfa (1.66 ton DM/acre), followed by Matrix alfalfa with 1.49 ton DM/acre. The lowest DM was with ST Tower alfalfa variety (0.89 ton DM/acre). For the second cut in early August (2nd of 2-cut system), Matrix alfalfa had the highest DM (2.82 ton DM/acre), followed by Algonquin alfalfa (2.23 ton DM/acre), then Spredor 4 alfalfa (2.04 ton DM/acre) and then Equinox alfalfa (2.00 ton DM/acre). Other legumes had < 2.00 ton DM/acre. The total DM yield resulting from early June + early August cuts was in the following order for the top 6 alfalfa: Matrix > Multi 5301 > Algonquin > AC Blue J > AC Caribou > Spredor 4.

When cutting was delayed in the year until early August (August only cut), 7 of the 13 legumes had higher DM yields than any of the other cutting treatments (early June only cut or the 2-cut system (early June + early Au-gust)). For the August only cut, the top 5 legumes were all alfalfa varieties, had >3.00 ton DM/acre and were in the order of: Algonquin > AC Caribou > Matrix > Blend 2220 > 53V52.

The average DM yield when pooled across the cutting treatments for High Prairie forage plots varied from 2.23 to 3.67 ton DM/acre for the legumes. The top 5 legumes (all alfalfa) with higher average DM yield for the year were: Matrix, Multi 5301, Algonquin, AC Blue J & AC Caribou.

Forage Quality

Grasses (Table 1)

The forage protein content was mostly higher for early June than early August cuts. Palaton reed canary grass had the highest protein for any cuttings in June. For any of the August cuts, Climax timothy had the highest protein. The protein requirements of a dry gestating and a lactating cow were generally met by the selected top grasses when cut in June (except for AC Goliath crested wheatgrass). With the exception of Climax timothy and AC Rocket smooth bromegrass which had 12.5 - 13.4 % protein, the selected grasses were only mostly able to meet the protein requirement of a dry gestating cow in the mid-pregnancy stage. Looking at Table 1, Climax timothy, AC Rocket smooth bromegrass and AC Goliath crested wheatgrass had much lower protein contents (4.9 - 6.4% CP) when cutting was delayed until August cut for August only cut, and therefore these grasses fell short of meeting the protein requirements of both dry gestating and lactating cows.

The requirements for Ca, P and Mg by a dry gestating cow in the mid and late pregnancy stages were mostly met by the selected grass varieties. The few exceptions were when cutting was delayed from early June till early August. Of the top 7 selected grass varieties, AC crested wheatgrass generally had lower macro-mineral contents measured in this study and these minerals were mostly short of meeting a dry gestating cow requirements. The forage K content varied from 0.58 to 3.35% for the selected 7 grass varieties, with only AC Goliath crested wheatgrass when cut in August falling short of what a dry gestating cow needs. Forage Na content was mostly 0.01% for all grasses and this fell short of the requirement of a dry gestating cow.

Forage energy content varied from varied from 55.5 to 61.1% TDN for the selected 7 grass varieties. With the exception of a few cases, the energy requirements of lactating and non-lactating cows were generally met by the selected grass varieties even when cutting was delayed from early June until early August.

Legumes (Table 2)

Forage protein content was generally >13% for the selected legume varieties, indicating that the 7, 9 & 11% protein needed by a cow in the mid-pregnancy, late-pregnancy and lactating stages have been met and even exceeded by the legumes.

Forage Ca content varied from 0.80 to 2.13%for the selected legumes and the needed amounts by a dry gestating and a lactating cow were exceeded by all legumes. The P requirement by a dry gestating cow were met by the selected legumes but the legumes only on a few occasions met the 0.26% P needed by a lactating cow. The requirements of Mg and K by a dry gestating cow in the mid and late pregnancy stages were generally met by the selected legume varieties. The Na needed by a beef cow has not been consistently met.

Forage energy content varied from varied from 53.9 to 61.2% TDN for the selected legume varieties. With the exception of when AC Caribou was cut in early August for the August only cut treatment, the energy requirements of a lactating and a non-lactating cow were mostly met by the selected legume varieties even when cutting was delayed from June until August.

Forage Selenium Content

The selenium (Se) requirement of beef cattle is 0.10 mg/kg of diet dry matter. From the forage demonstration plots in High Prairie, the following forages from the August only cut were analyzed for selenium content: Tall fescue (0.11 mg/kg Se), Anik alfalfa (0.11 mg/kg Se), Carlton smooth bromegrass (0.10 mg/kg Se), Fleet meadow bromegrass (0.26 mg/kg Se) and Algonquin alfalfa (0.18 mg/kg Se). The Se requirement of beef cattle have been met by the selected grass and legume varieties.

General Notes

All alfalfa varieties tested at the High Prairie plots appeared to be less affected by winter kill even with the different cutting treatments. Delaying cutting in the year until early August seemed to have affected alfalfa stands more than grasses over time. The clover and cicer milkvetch varieties have not been doing well at the site. Hay from grasses cut in early August (for August only cut) would not generally be as palatable as those cut in early June (for June only) or early June + early August cuts (for 2-cut system) because of reduced forage quality and advanced growth.