Performance of alfalfa-sainfoin mixed pastures and grazing steers in western Canada

A multi-year, multi-location grazing study with alfalfa (Medicago sativa L.) and sainfoin (Onobrychis viciifolia Scop.) mixed pastures was undertaken to determine pasture productivity and quality. At Lethbridge, mixed pastures of 3 experimental sainfoin populations (LRC-3401, LRC-3432, and LRC-3519) and Nova sainfoin with AC Blue J alfalfa were established in a replicated experiment in 2008. A similar experiment with Beaver alfalfa was established in 2009 at Swift Current, Saskatchewan, Canada (SC). The experimental populations were developed to persist in mixtures with alfalfa under a multiple-cut system. Pastures were grazed by steers using a rotational grazing system at a stocking rate of 4.0 animal unit month ha/yr (8.6 steers/ha per season). Four-year mean DM yields of LRC-3432 (10,713 kg/ha) and LRC-3519 (10,530 kg/ha) mixed pastures were higher (P < 0.05) than Nova (9,668 kg/ha) pastures. Percentages of DM in LRC-3432 (28-30%) and LRC-3519 (30-43%) in the mixed pastures were higher (P < 0.05) than Nova (5-8%) after the first rotation of grazing in all years at Lethbridge and in 2010 at SC. In continuous stocking experiments with different alfalfa mixtures, the same 2 sainfoin lines produced higher (P < 0.05) DM forage yields than Nova at Lethbridge but not at SC. Average daily gains of steers varied between 0.7 and 1.2 kg/d at both Lethbridge and SC, but the differences among pastures were not significant. New sainfoin populations, LRC-3432 and LRC-3519, can be used in alfalfa pastures for high ADG and bloat prevention, because they produced high DM yields and proportions in the mixed pastures.