Evaluation of free-choice feedstuffs preference by pigs

In newly weaned piglets, ensuring a fast initiation to feeding is essential to maintain gut function and growth. Formulating diets with ingredients for which piglets have an innate preference might facilitate feed intake initiation around weaning. Free-choice feeding protocols have been widely used to assess pig's preferences for different feeds. Feed preference values are strongly influenced by the methodology used (i.e. reference feed used, experience of the pigs, length of test, etc.) and this should be considered when interpreting the results. In this paper data from pigs' preferences trials is reviewed. Data is grouped according to the nature of the feed ingredients studied (cereals, protein sources, free amino acids, fats and oils, fibre sources and other additives). The relationship between preference and the physical properties of the feeds (i.e. particle size and texture parameters) and their nutritive value is discussed, and practicalities for the use of freechoice preference data under practical (no-choice) conditions are also considered.