Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/1997
Publication Date: N/A
Interpretive Summary: In many production situations the daily dry matter that an animal consumes may be more important than digestibility in limiting animal production. An understanding of the animal ques that determine preference and hence food intake would improve production efficiency. Determination of specific compounds in forage that impart preference would form the basis of a whole new industry directed to improving production efficiency. The multidimensional scaling procedure, previously applied to studies of human preference, proved to be a valuable tool in investigating sheep dietary preferences. It systematized data in these trials by converting preference for forage into coordinates in a three-dimensional map. These coordinates made it possible to relate forage characteristics to preference through statistical procedures. For hays, digestibility and soluble carbohydrates were most important in determining preference. For fresh forages, preference was influenced most by lower disacchrides, an unidentified fraction and soluble carbohydrates.
Technical Abstract: Forage preference is a difficult but important factor in determining dry matter intake. In two experiments, six individually-penned animals (wethers, Exp. 1; ewes, Exp. 2) were used to obtain preference ratings on nine hays (four cultivars of temperate grasses, four cultivars of subtropical grasses, and a legume, Exp. 2) arranged in 36 pair combinations sand offered for 3 d (Exp. 1) or for 1 d (Exp. 2). Multidimensional scaling showed concentrations of IVDMD, monosaccharides, short-chain polysaccharides (SCP), and disaccharide in dimension 1; ash monosaccharide and SCP, and masticate NDF in dimension 2 and disaccharide and starch in dimension 3. For fresh forage these were: concentration of disaccharide and median particle size in dimension 1; starch and monosaccharide + disaccharide in dimension 3. No variables measured were associated with dimension 2. Multidimensional scaling systematized the data in these trials and provided a framework for relatin physicochemical characteristics of forages to preference.