EFFECTS OF EARLY EXPERIENCE VOLUNTARY INTAKE OF LOW-QUALITY ROUGHAGE BY SHEEP

This study determined 1) how experience early in life with cured weepi ng lovegrass (Eragrostis curvula) (low-quality roughage) or fresh oats (Avena sativa) (high-quality roughage) affected consumption of low- o r high-quality roughage by lambs later in life and 2) whether this ear ly dietary experience affected passage of undigested residues through the digestive tract and digestion of low-quality roughage. From 1 to 5 mo of age, experienced lambs (EL) were grazing cured weeping lovegras s, whereas inexperienced lambs (IL) were grazing fresh oats. Immediate ly after exposure, in Trial 1 lambs were fed sorghum( Sorghum bicolor) hay(low-quality roughage) supplemented with 9 protein concentrate. In Trial 2 lambs were offered sorghum only. Finally, in Trial 3 lambs we re offered a choice between sorghum and alfalfa hay. When the sorghum was supplemented with protein there was no difference (P > .05) betwee n treatments in intake of sorghum, but when the supplement was withhel d in Trial 2, EL ingested 20% more (P < .01) sorghum than IL. When giv en a choice between sorghum and alfalfa, EL ingested 2.5 times more (P < .01) sorghum than IL. The apparent digestibility of sorghum was 4.5 % higher(P < .01) in EL than in IL, whereas passage of undigested matt er through the digestive tract was similar(P > .05). The results show that early dietary experience can have a significant effect on consump tion of low-quality roughage and diet selection in free-choice situati ons.