Voluntary feed intake in growing-finishing pigs: A review of the main determining factors and potential approaches for accurate predictions

The ability of pigs to consume sufficient nutrients for optimal performance is an important consideration in commercial pork production. Nutrient intake levels are directly related to voluntary feed intake. Voluntary feed intake in pigs is influenced by several factors including environmental conditions (e.g. thermal and social conditions), animal status (e.g., age and physiological status), and feed and feeding conditions (e.g. bulkiness of the feed and feed form). Although the individual effects of many of these factors on voluntary feed intake have been investigated and quantified, little has been done to characterize their interactive effects. Under commercial conditions, voluntary feed intake is clearly influenced by multiple factors at any one time. Thus, there is a need for a means to accurately quantify voluntary feed intake in pigs as affected by the different interacting factors. Until quantitative effects of these interactions are established it is suggested that feed intake be monitored. This can be achieved by obtaining feed intake on representative groups of pigs.