/AnMtgsAbsts2009.52108 Impact of Forage Novelty On Diet Preference of Beef Steers.

Monday, November 2, 2009
Convention Center, Exhibit Hall BC, Second Floor
Holly Boland, Prairie Research Unit, Mississippi State Univ., Prairie, MS, Guillermo Scaglia, Iberia Research Station, Louisiana State Univ., AgCenter, Jeanerette, LA, D. R. Notter, Virginia Polytechnic Inst. & State Univ. (Virginia Tech), Blacksburg, VA, A. J. Rook, Inst. of Grassland and Environmental Research, Former Team Leader, Devon, EX20 2SB, United Kingdom, A. Ozzie Abaye, Crop & Soil Environmental Sciences, Virginia Polytechnic Inst. & State Univ. (Virginia Tech), Blacksburg, VA, W. S. Swecker Jr., Virginia Maryland Regional College of Veterinary Medicine, Blacksburg, VA and J. H. Fike, Crop and Soil Environmental Sciences, Virginia Polytechnic Inst. & State Univ. (Virginia Tech), Blacksburg, VA
A number of studies have evaluated the behavior of sheep and cattle grazing adjacent monocultures of perennial ryegrass and white clover. In those studies, animals almost always chose a diet of around 70% white clover. Several theories have been proposed to explain why domestic ruminants have this pattern of preference and why they select mixed diets of grass and legume, but only a few forage species have been evaluated in this manner. Two different forage species were thus chosen for examination as adjacent monocultures; tall fescue (Festuca arundinacea Schreb. or Lolium arundinaceum (Schreb.) S.J. Darbyshire) and alfalfa (Medicago sativa subsp. sativa L.). The hypothesis that ruminants select mixed diets in part based on a plant’s ‘novelty’ was evaluated along with the theory that regardless of species evaluated, cattle will have greater preference for legume than grass. Cattle without previous exposure to alfalfa spent 78% of their grazing time consuming alfalfa, whereas cattle that had previously grazed alfalfa spent less time (P = 0.04) grazing alfalfa (72%). Overall proportion of the day spent grazing both forages was lower (P = 0.0001) when alfalfa was novel (40%), compared to when steers were experienced grazing both forages (46%). Proportion of the day spent idling was greater (P < 0.0001) when alfalfa was novel (35%), compared to when both forages were familiar to the steers (26%). The proportion of grazing time in alfalfa was greater (P = 0.02) in afternoon (76.8 %) than in morning (72.1 %). This result differs from previous studies that reported a decline in preference for legume over the day, with increased preference for grass in afternoon.