Diet preference of lambs offered a choice of concentrate diets containing different proportions of wheat dried distiller’s grain with solubles

This study aimed to determine if lambs alter the intake preference for diets based on the grain components of the diet. The concentrate diets consisted of either 20 or 40% wheat dried distiller’s grain with solubles (WDDGS) or 60% barley (control), diets were formulated following NRC requirements for growing lambs. Crude protein concentration (% in the DM) for control, 20 and 40% WDDGS diets were 15.8, 17.3 and 18.9, respectively. A total of 36 lambs (105 days of age, live weight 33.5 ± 4.6 kg) were assigned at random to one of three pens each equipped with automatic sheep feeders. Lambs in each pen had ad libitum access to all three diets for 7 days, before the groups rotated between the three pens. This ensured the complete random design during the 45 day experimental period. Using automatic feeders allowed the recording of daily feed intake and therefore preference for a particular diet for each individual sheep. Preference of diet (measured by total feed intake) varied over the course of the trial on a weekly basis (interaction treatment by week P < 0.001). Overall lambs had higher total feed intake of diets supplemented with WDDGS compared to the barley grain control. There are several possible explanations as to why the lambs may have preferred the WDDGS diets over the control, including the aspects of feed novelty, variety and palatability, as well as the higher crude protein (CP) content of the WDDGS diets.