Site: Fairview Research Farm
Research Coordinator: Dr. Akim Omokanye
Observations Following Cutting Treatments
Thirty two perennial forage species and varieties were established in June 2010 (Table 1). The number was increased to 42 species and varieties in June 2011. Establishment procedures and progress on those established in 2010 were presented in the PCBFA 2010 Annual Report and are also available on the ARECA website.
The perennial forage demonstration plots are being used to showcase new forage species and varieties in parts of the Peace region. The forage varieties are being observed for adaptation, tolerance to drought, winter hardiness, recovery after cutting and potential for multiple cuts, over a 5-year period. With this trial, farmers will be able to appraise for themselves both traditionally grown and new forage species that have been developed and released in recent years. This report outlines the second year’s progress, with focus on forage DM yield and quality following different cutting dates.
In Fairview, the forage demonstration site is located at the Fairview Research Farm (RR #35). Early in spring of 2011, notes were taken on winter kill and the site was fertilized with 50 lb N + 20 lb P.
Each forage variety plot was divided into 3 sections, each measuring 2.5m x 6m. Sections 1, 2 and 3 were respectively cut in June (1 cut only), June & August cuts (2 cuts—first cut in June and then the regrowth cut in August) and August cut (1 cut only - delayed cutting until August). Forage DM yields were estimated from each cut. Forage quality of 7-8 top yielding forages for the year was determined. Selenium content for some forages were also analyzed.
Results and Discussion
Forage DM yield In most cases, June only cut, produced greater forage DM yields than June & August double cuts or August only cut (Figure 1). Crested wheatgrass (Kirk), Hybrid bromegrass (AC Knowles), Reed canary grass (Palaton) and Meadow bromegrass (Fleet) all produced higher forage yield (>4000 lb DM yield/acre) than other forages when cut in June. The regrowth forage DM yield was
greater for Reed canary grass (Palaton), Smooth Bromegrass (AC Rocket), Timothy (Grindstad) with well over 2000 lb/acre. The least favoured regrowth was Meadow bromegrass (Fleet), which had 1173 lb/ acre. However, when looking for grasses for double cuts potential, Crested wheatgrass (Goliath), Smooth Bromegrass (Carlton), Smooth Bromegrass (AC Rocket), Crested wheatgrass (kirk), Meadow bromegrass (fleet), Hybrid bromegrass (AC Knowles) and Reed canary grass (Palaton) seemed to have the potential for this purpose. They all produced between 5620 and 7111 lb/ acre/year. August only cut seemed to favour Crested wheatgrass (Goliath) and Smooth Bromegrass (Carlton) more than other grasses. Across all the grasses, June cut produced the higher average forage DM yield, followed by August harvest and then the June regrowth.
In most cases, forage DM yield from June & August double cuts was more than twice the yields of either June or August only cut. (Figure 2). For August only cut, only Matrix alfalfa produced higher than 4000 lb/acre, while other legumes produced between 2505 and 3879 lb/acre. Across all the legumes examined, cutting the June regrowth in August (double cuts) favoured estimated DM yield than either single cut in June or August.
Generally, delaying forage cut until August reduced crude protein contents of selected grasses and legumes. The regrowth following June cut had higher mean protein contents than those cut once (June or August only) for both grasses and legumes. Taking into consideration the 7-9-11 % requirements for dry pregnant beef cows through to post calving, all the grasses and legumes met and even far exceeded these amounts
(11-22% CP for legumes). The only exceptions for the grasses are - Grindstad timothy (8.78% CP) and Fleet meadow bromegrass (8.26% CP), which resulted from delaying cutting till August.
Table 1 shows mineral (Ca & P), detergent fiber and energy contents of selected forages in Fairview. For the grasses, regrowth from June cut consistently favoured forage mean Ca and P contents than just June or August only harvest. NDF seemed to be slightly better also with the regrowth. For the legumes, except for the August only single cut which met the requirements for macro-minerals such Ca and P vary depending on the class of animal, and the level and state of production. The P requirements for dry pregnant and lactating cows (0.22-0.25% P) could not be met by most grasses regardless of when cutting was done. Only a few number of grasses met the Ca content requirements at any point. All legumes met and exceeded the Ca and P contents requirements of dry pregnant and lactating cows.
Forage Selenium Content
The selenium (Se) requirement of beef cattle is 0.10 mg/kg of diet dry matter. Formulating diets to contain 0.2 mg/kg is recommended. The Se content of feeds grown in Alberta is quite variable. According to the information on the ARD website, approximately 20% of legume and grass-legume forages, and 50% of grass and cereal forages do not contain the required concentration of Se. About 55% of cereal grains are deficient in this element. The majority of the feed grown in the northern and western parts of the province contain less than the required concentrations of Se.
Selenium is required for catalysing the destruction of toxic oxygen molecules produced during metabolism, thereby protecting the cells from damage and helps with the absorption of fat, including vitamin A and vitamin E, and in proper sperm formation. Deficiency symptoms include unthriftiness and reduced growth. Impaired immune response also occurs, which makes the animals more susceptible to disease.
A few forage samples from our demonstration plots in Fairview were analysed for Se content. Regardless of when they where cut, the 3 forages analysed for Se satisfactorily met the suggested range of 0.1-0.2 ppm (mg/kg) of diet dry matter, except for the June regrowth of Anik alfalfa (Table 3).
For the grasses, Tall fescue (Pradel Meadow), Tall fescue (Climax), Crested wheatgrass (Kirk), Meadow bromegrass (Fleet), Timothy (Derby), Reed canary grass (Palaton), Grindstad timothy and Creeping red fescue (Boreal) were less affected by winter kill than other grasses. Perennial ryegrass (BG 34) died out after one year.
For the legumes, Anik alfalfa was the least affected by winter kill, while Alsike clover (Aurora) was the most affected by winter kill. In early spring of 2011, both cicer milkvetch varieties were still slow to establish even one year after seeding, but seedling stands and plant growth improved significantly with time.