How forage characteristics influence behaviour and intake in small ruminants: a review

Small ruminant production systems vary widely, from high producing dairy go ats to suckling ewes on rangelands. However, in all environments feed chara cteristics influence animals' motivation to eat, dietary choices and ultima tely nutrient intake. This review highlights the common feed factors that i nfluence feeding behaviour and intake, although their expression and conseq uences depend on the environment. The main characteristics of feeding behav iour are described in terms of the satiation process and motivation to eat. The main feed factors that influence intake are then reviewed. The relatio nship between the nutritive value of forages and their voluntary intake is well established. The relationship between nutritive value and palatability of feeds is discussed in the light of recent work on how feed characterist ics are learned. At pasture, ease of prehension of the sward influences rat e of intake and dietary choices. On heterogeneous resources, animals grate selectively and choose a diet of higher quality than that on offer. Recentl y more effort has been made to model intake and foraging decisions. Managem ent of the sating circuit has become an important factor in a heterogeneous environment. In conclusion, modelling and predicting intake for small rumi nants in different environments are briefly discussed.