EFFECTS OF VOLATILE COMPOUNDS ON CONSUMPTION OF ALFALFA PELLETS BY SHEEP

We examined the effects of six volatile compounds on alfalfa pellet co nsumption by lambs. In each experiment, 45 lambs were individually fed alfalfa pellets sprayed with a selected compound (camphor, limonene, cis-jasmone, beta-caryophyllene, borneol, or alpha-pinene) at one of f ive concentrations. Treatment concentrations were multiples (0, .5, 1, 2, and 10) of the concentration of a specific compound (X) that was r elated to differential herbivory of tarbush by livestock in previous s tudies. Treatments were applied to alfalfa pellets (.64 kg.lamb(-1).d( -1), DM basis), and consumption was measured during a 20-min interval each morning for 5 d. Lambs were adapted to handling procedures and th e pelleted diet (without treatments) for 10 d. Lambs were maintained a nd fed (approximately 4.5 to 5% of BW) as one group except during 20-m in tests. A negative linear effect of treatment concentration on intak e was observed for camphor (P < .02) and alpha-pinene (P < .01), and a quadratic response was detected for borneol (P < .02). The other thre e compounds had no discernible effect on consumption. Although volatil e compounds generally had only minor influences on consumption, the ne gative influences of alpha-pinene and camphor concentrations on pellet consumption suggest that these monoterpenes may partially explain dif ferential herbivory of individual tarbush plants by livestock.