Preferences of sheep and goats for straw pellets treated with different food-flavouring agents

In order to assess differences in preferences for flavours between ruminant species, two-choice tests were conducted on sheep (Scottish Blackface, Ovis aries) and goats (feral hybrids, Capra hircus). Feed pellets (nutritionally improved barley straw) were treated with synthetic human food-flavouring agents representing: strawberry (ST), apple (AP), orange (OR), maple (MA), caramel (CA), truffle (TR), garlic (GA) and onion (ON) flavours. Animals were first exposed to each of the flavours and then presented with each, paired with an untreated (control) feed, and the consumption of individual feeds recorded. Preference values (PV) were calculated from the proportion of the total feed consumption derived from the flavour-treated feed. Differences in PV were found between species (P = 0.01) and between flavours (P < 0.005). Although sheep showed stronger preference for flavoured feeds than did goats, both sheep and goats showed a similar pattern of preference across the flavours offered. In general, sheep exhibited significant preference for TR, GA, ON, AP, CA, MA and OR relative to the unflavoured feeds, whereas goats showed significant preference for TR, ON, AP and GA. The findings of this research suggest that it would be of practical use to evaluate feeds flavoured with compounds representing truffle, garlic and onion as intake enhancers in goats and sheep. Only if flavouring agents are successful in enhancing intake could we recommend flavouring as a means of masking undesirable feed flavours, production of a more uniform feed from variable ingredients or in prompting feed consumption.