Accumulation Period for Stockpiling Perennial Forages in the Western Canadian Prairie Parkland

Abstract

Grazing stockpiled perennial forage can reduce a beef producer's winter feeding costs. The objective of this study was to determine optimum rest or accumulation periods for perennial forage species adapted to the western Canadian parkland. The research was conducted for 3 yr at Lacombe, AB, Canada. Stockpiled forage grass and alfalfa species (Medicago sativa L., M. falcata L.), with four accumulation periods, were harvested (second cut) on 15 October after a first cut on one of four dates: 1 July, 15 July, 1 August, or 15 August. Forage yield and nutritive value were determined for each period–species combination. Nutritive value measurements included concentrations of in vitro digestible organic matter (IVDOM), crude protein, water‐soluble carbohydrates (WSC), and neutral detergent fiber (NDF). ‘Algonquin’ alfalfa yielded more than ‘SC MF3713’ alfalfa and all grasses during 1998 (Year 1) when cut on or after 1 August. However, by 2000 the yield differences among species had decreased at periods beginning 1 and 15 August. Meadow bromegrass (Bromus riparius Rhem.) had stable yields from year to year and was similar to or greater than Algonquin at the 15 July period. Bromegrass and alfalfa species required an accumulation period beginning as early as 15 July, while others required first cutting as early as 1 July to provide adequate stockpiled yield. Alfalfa nutritive value decreased more with longer accumulation periods than grasses. Neutral detergent fiber and WSC concentrations of creeping red fescue (Festuca rubra L.) did not change substantially with accumulation period, making it desirable for stockpiling, given a long accumulation period.