Effect of Different Grinds on Digestibility and Efficiency of Pelleted Rations for Finishing Beef Cattle

The purpose of this experiment was to determine if the preparation of a cattle finishing ration has any effect on its digestibility and feed efficiency.Twenty head of yearling Hereford steers were individually fed for 140 days.The steers were divided into five treatments of four animals each.All rations contained the same ingredients and differed only in the way they were prepared.The five rations were prepared as follows: (1) ground through 1/8 inch screen and pelleted, (2) ground through 2/8 inch screen and pelleted, (3) ground through 3/8 inch screen and pelleted, (4) ground through 3/8 inch screen pelleted and reground, (5) ground very course and not pelleted.The rations contained 67 percent No. 2 yellow corn, 25 percent sun cured baled alfalfa hay, 2.5 percent soybean oil meal, 5 percent molasses and 0.5 percent dicalcium phosphate.Each steer received as much feed as it could readily consume without wastage. The chromic oxide technique was used in determining the apparent digestibility coefficients.Digestibility of crude fiber was significantly higher in the coarsely ground ration than in the pelleted rations.Regrinding the pelleted ration reduced the digestibility of the other extract in the ration.No significant difference was found in the digestibility of dry matter, crude protein and energy; however, the regrinding of the 3/8 inch ground and pelleted ration (Ration 4) resulted in lower digestion coefficients for these nutrients. There was no significant difference in rate of gain or efficiency of feed utilization between treatments; however, animal variation was great within treatments.Steers fed Rations 3 and 5 had the highest intakes, feed efficiencies and gains.The feed required per 100 pounds of gain was 857, 921, 787, 837, and 794 pounds respectively for Rations 1, 2, 3, 4, and 5.The average daily gains were 2.42, 2.23, 2.76, 2.43, and 2.79 pounds, respectively. With the exception of the digestibility of crude fiber, grinding and pelleting had no effect on the digestibility and feed efficiency of the cattle finishing ration used in this experiment.Crude fiber digestibility was lowered.Regrinding the pelleted ration lowered the digestibility of all the nutrients except crude fiber; however, ether extract was the only one that was significantly lowered. Advisor: Donald C. Clanto