Effect of perennial forage system on forage characteristics, soil nutrients, cow performance, and system economics

Two perennial forage systems were evaluated in a 3-yr study for their effect on forage biomass and nutritive value, botanical composition, soil nutrients, forage disappearance, beef cow performance, and economic analysis. Spring-calving, dry, pregnant Bos taurus beef cows [yr 1 (n = 60), 632 ± 8 kg; yr 2 (n = 60), 638 ± 5 kg; yr 3 (n = 48), 653 ± 5 kg] were managed in 1 of 2 replicated (n = 3) forage systems: (1) grazing stockpiled perennial forage [TDN = 52.5, CP = 10.7 (%DM); SPF] in field paddocks or (2) drylot pen feeding round bale hay [TDN = 52.7, CP = 10.0 (%DM); HY]. Forage utilization was greater (P = 0.01) for HY cows in all years (94%) compared with yr-1 and yr-2 SPF cows (58 and 78%, respectively). Forage disappearance was greater (P = 0.01) for yr-3 SPF cows than HY system cows; however, supplement was greater (P = 0.01) for SPF cows compared with HY cows during the study period. Soil NO3-N (P = 0.02) and organic carbon (P = 0.01) amounts at the 0- to 30-cm soil depth were greater in SPF paddocks than HY paddocks. Body weight and BCS did not differ (P > 0.05) for cows in either SPF or HY systems. Averaged over 3-yr, SPF total system costs were 14% less (P = 0.01) compared with the HY system. Results suggest field grazing stockpiled perennial forages in western Canada can be a viable strategy without any negative effect to beef cow performance.