Effects of Food Structure and Nutritional Quality and Animal Nutritional State on Intake Behavior and Food Preferences of Sheep

Document Type


Journal/Book Title/Conference

Applied Animal Behavior Science

Publication Date







There is evidence of the independent effects of plant physical and chemical characteristics on foraging, but little has been done to determine how these traits interact to affect food selection. We determined if the nutritional state of lambs (Ovis aries) affected intake behavior and preference for foods with different ratios of protein/energy (alfalfa: high proportion protein/energy; barley: high proportion energy/protein), presented in different physical forms (whole or ground). Changes in nutritional state were induced by altering the nutritional composition of the basal diet (high [Ep] or low [eP] proportion of energy/protein). We determined preference for barley and alfalfa (whole or ground) when lambs were fed (1) a nutritionally balanced diet with a 15-h (overnight) fast (Period 1), (2) an unbalanced diet (Ep or eP) with a 15-h (overnight) fast (Period 2), and (3) an unbalanced diet without a fast (Period 3). Averaged across the three periods, all lambs preferred barley to alfalfa (PPPPPP>0.05). These differences in intake of energy and protein by lambs fed the unbalanced diets led to a steady increase in the ratio of protein/energy selected by lambs fed the balanced basal diet and diet Ep during Periods 1, 2, and 3 (7.9, 11.7, 13.9 g CP/MJ), and a constant ratio of protein/energy selected by lambs fed the balanced basal diet and diet eP during Periods 1, 2, and 3 (7.6, 8.1, 8.1 g CP/MJ; PP

First Page


Last Page