ARS | Publication request: YEARLING CATTLE UTILIZATION OF A HIGH MAGNESIUM TALL FESCUE

Submitted to: Society for Range Management Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 13, 1994
Publication Date: N/A

Technical Abstract: HiMag is an experimental tall fescue (Festuca arundinacea Schreber) which was developed to counter the annual $15 to 45 million hypomagnesemic-death loss in cattle grazing fescue in the U.S. We measured animal utilization of HiMag relative to 7 other tall fescues grown on an irrigated soil near Kimberly, ID. The experimental design was a split-split block where blocks = 4 pastures, main plots = 3 replications, subplots = 8 entries, and sub-plots = 6 adjacent rows of a given entry. Subplots were 6.5 m long and rows were 0.56 m apart. Six yearling cattle grazed these pastures once in fall 1992 and 4 times during 1993. Herbage mass was determined by clipping two 0.61 m sections before and another two after grazing each subplot. Utilization was estimated on a 0 to 10 point scale by 4 observers at 30 and 48 hours after initiating grazing. A selection ratio was calculated as the relative amount eaten (test entry vs. total) divided by relative amount available (test entry vs. total). In fall 1992, 48 hr. utilization scores for entries ranged from 3.9 to 7.2 with a 5.1 average, while average forage consumption was 45%. Animal preference for HiMag was intermediate or equal to that of the KY-31 and MO-96 parents. Selection ratios were not different for the 3 cultivars. Data will be collected for 1994.