The 2008 Joint Meeting of the Society for Range Management and the America Forage and Grassland Council. |
Wednesday, January 30, 2008
16
Evaluating Grazing Preference and Production Differences among Four Crested Wheatgrass Cultivars
Alan D. Iwaasa1, Bruce Coulman2, and Edward J. Birkedal1. (1) AAFC, Semiarid Prairie Agricultural Research Centre (SPARC), #1 Airport Road, Swift Current, SK S9H 3X2, Canada, (2) AAFC, Saskatoon Research Centre, 107 Science Place, Saskatoon, SK S7N 0X2, Canada
Study objective was to evaluate beef and forage production and grazing preference differences among different crested wheat grasses (CWGs). The study evaluated four CWGs: Kirk, Fairway, AC-Parkland and AC-Goliath. Each CWG was randomly seeded in 2003 into a 13.4 m x 304 m strip (0.4 ha) and replicated five times and also as production pastures (0.7 ha) and replicated twice. The study was a completely randomized design and conducted in 2005 to 2007 at SPARC-AAFC. Main treatment effects were cultivar, time period and year. Observations of animal distribution and grazing activity were recorded at 15-minute intervals during the second day of each yearly grazing period. All CWGs were grazed at the late boot to early head stage. Animal grazing frequencies for each CWGs were converted to percentages (Grazing%) for each time period: morning (sunrise-1200 h), afternoon (1215-1700 h) and evening (1715-sunset). Each production pasture was grazed by three yearling steers and average daily gains (ADG), available forage yield (AYD) and total live production (TLP) were measured. A significant (P=0.05) interaction was observed (cultivar x year) for Grazing%. Kirk had the highest Grazing% value (P=0.07) compared to other cultivars. Higher (P<0.001) Grazing% occurred in the morning (10.6 ± 0.6%) compared to afternoon (8.6 ± 0.6%) and evening (7.1 ± 0.6%). Forage qualities (OMD, ADF, and CP) did differ (P<0.05) among CWG cultivars. Significant (P<0.05) two way interaction (cultivar x year) was observed for AYD and no differences for ADG and TLP were found. Grazing preference differences among CWGs were observed over years and this information may provide a management tool to better utilize CWG pastures.