EATING BARLEY TOO FREQUENTLY OR IN EXCESS DECREASES LAMBS PREFERENCE FOR BARLEY BUT SODIUM-BICARBONATE AND LASALOCID ATTENUATE THE RESPONSE

We conducted experiments to determine whether preference for barley wa s affected when lambs ate various amounts of barley and whether lambs ate more barley when it contained lasalocid and sodium bicarbonate (Na HCO3), both of which attenuate acidosis. In Exp. 1, lambs were assigne d to two treatments (six lambs/treatment). For 2 d, lambs in two treat ments were offered either 400 or 1,200 g of rolled barley from 0600 to 0700 as a preload meal. A preference ratio [PR = barley ingested/(tot al amount of alfalfa + barley ingested)] was calculated based on lambs ' intake when offered a choice of 200 g each of rolled barley and alfa lfa pellets hourly from 0700 to 1100. After the preload meal, lambs in Treatment 1 (400 g preload) showed equal preference for barley (.52) and alfalfa (.48) for 4 h on d 1 (P > .05); their preference for barle y was less after the meal of barley on d 1 (.52) than on d 2 (.72), bu t their preference for barley declined between h 3 (.81) and 4 (.55) o f d 2 (P = .11). Lambs in Treatment 2 (1,200 g preload) showed a low p reference for barley on d 1 (.29) and 2 (.19) (P < .001). In Exp. 2, l ambs were assigned to four treatments (six lambs/treatment): 1) rolled barley + NaHCO3 (2%) + lasalocid (33 ppm); 2) rolled barley + NaHCO3 (2%); 3) rolled barley + lasalocid (33 ppm); or 4) rolled barley. Inta ke of barley by lambs offered NaHCO3 + lasalocid (Treatment 1) was gre ater (P = .07) than that by lambs offered NaHC03 (Treatment 2), wherea s intake by lambs offered lasalocid (Treatment 3) was similar (P > .05 ) to that by controls. We conclude that eating barley too frequently o r in excess caused a decrease in lambs' preference for barley and that ; NaHC03 and lasalocid attenuated the aversion.