PSX-9 Effects of dietary levels of alfalfa and Sericea lespedeza hay on feed intake and growth performance by growing Alpine doelings and Katahdin ewe lambs

Abstract

Abstract Twenty-four Alpine doelings (initial BW and age of 25.3±0.55 kg and 10.4±0.11 mo, respectively) and 24 Katahdin ewe lambs (24; 28.3±1.02 kg and 9.6±0.04 mo, respectively) were used to determine effects of dietary levels of alfalfa and Sericea lespedeza on feed intake and growth performance. The treatment arrangement was a 2 × 3 factorial. Animals were housed in pens fitted with Calan feeding gates during the study with 4 periods, the first 3 periods were 42 d in length and the fourth 47 d. Diets consumed ad libitum were 75% coarsely ground hay. Forage was alfalfa, a 1:1 mixture of alfalfa and lespedeza, and lespedeza. There were no significant interactions between breed and diet or significant three-way interactions involving period (P > 0.05). Intake of DM in g/d was much greater for Katahdin than for Alpine (P < 0.001; 1,817 vs. 1,274; SEM=51.1), with differences of lesser magnitude in % BW (P = 0.063; 4.14 vs. 3.84; SEM=0.110) and g/kg BW0.75 (P = 0.001; 106 vs. 92; SEM=0.993). All expressions of DMI were similar among diets (P ≥0.199; 1,600, 1,585, and 1,452 g/d, SEM=62.6; 3.97, 4.10, and 3.89% BW, SEM=0.134; 99, 102, and 96 g/kg BW0.75 for alfalfa, alfalfa-lespedeza, and lespedeza, SEM=3.2). The ADG was greater for Katahdin than for Alpine (P < 0.001; 180 vs. 88 g, SEM=5.0) and ranked (P < 0.05) alfalfa > alfalfa-lespedeza > lespedeza (159, 132, and 111 g, respectively; SEM=6.1). The ratio of ADG:DMI was greater for Katahdin than for Alpine (P < 0.001; 104 vs. 72 g/kg; SEM=3.4) and greatest among diets for alfalfa (P < 0.05; 101, 84, and 79 g/kg for alfalfa alfalfa-lespedeza, and lespedeza, respectively; SEM=4.2). In conclusion, the two small ruminant breeds and species responded similarly to dietary characteristics as impacted by the different forage levels.