GROWTH, DIGESTIBILITY AND VOLUNTARY INTAKE BY YEARLING STEERS GRAZING TIMOTHY (Phleum pratense) OR MEADOW FOXTAIL (Alopecurus pratensis) PASTURES

Abstract

Two experiments were conducted to compare the performance of animals grazing meadow foxtail or timothy pastures. In the first experiment, yearling Hereford steers continuously grazed timothy or meadow foxtail pastures (two 2.0-ha pastures/treatment using a put-and-take grazing system for three consecutive years). Carrying capacity was 443 and 501 animal-days ha−1 for timothy and meadow foxtail, respectively (P<0.01). Average daily gain was 1.13 and 0.79 kg d−1 for steers grazing timothy and meadow foxtail, respectively (P < 0.01). Despite a lower carrying capacity, timothy pastures produced more 502 vs. 391 kg liveweight ha−1 yr−1 than meadow foxtail pastures (P < 0.01). In the second experiment, lignin and chromium mordanted fiber were used as dual markers to estimate digestibility and voluntary intake of grazed forage by four mature fistulated steers (two steers/treatment) over the grazing season. Digestibilities of dry matter (DM), crude protein (CP) and acid detergent fiber (ADF) were greater for timothy than for meadow foxtail (P <0.01) but no differences were observed for DM and digestible DM intake. Differences in forage quality, forage DM available for grazing or DM digestibility were not sufficient to explain the lower performance of steers grazing meadow foxtail compared to timothy. Key words: Pasture, forage quality, animal performance, timothy, meadow foxtail, beef cattle