Kelln, L., Newkirk, R. W., Smillie, J. et al. 2019. Does pellet size affect the ability of beef heifers to consume a pelleted supplement in a simulated grazing model? Canadian Journal of Animal Science 99(4), 943-950.

The objective was to evaluate pellet consumption and refusals as affected by pellet size. Six ruminally cannulated heifers were used in a replicated 3 × 3 Latin square. Heifers were individually housed and fed a diet of grass hay (57.5%), mineral and vitamin supplement (8.0%), and canola meal (11.9%) in a feed bunk, and their respective wheat- and wheat-middling-based treatment pellet (22.7%) on artificial turf. The artificial turf had a mean staple length of 5 cm and a blade density of 45 blades cm-2. The pellets were small (SM; 4 mm diameter), medium (MED; 11 mm diameter), or large (LG; 50 mm diameter) in size. Heifers fed LG had greater pellet intake than SM (2.24 vs. 2.06 kg; P = 0.035), with MED being intermediate (2.12 kg). Heifers fed LG tended to have less pellet waste than SM (P = 0.074). Heifers fed MED pellets had greater concentration of ruminal short-chain fatty acids than SM and LG (91.3 vs. 84.7 and 89.0 mmol L-1; P = 0.009). The results indicate that feeding a LG pellet may increase intake and reduce waste compared with SM, and that pellet size may also affect ruminal fermentation.