猪饲料的制备探讨UCM298447.ppt

Helpful Websites Kansas State University Grain Science and Industry / Feed line moving feed to individual pig feeders. Picture courtesy of Dr. Robert Goodband, Kansas State University, Swine Nutrition and Management Activity 2: Particle Size and Shape Break into groups of 3 or 4. Build a cup-shaped castle with dry (“as is”) sand and another castle with rocks or marbles. Activity 2: Particle Size and Shape Sandcastle holds shape better than the rock or marble castle. Activity 2: Particle Size and Shape Make a castle with rocks and one with marbles. See how the rocks stack together better than the marbles because of their irregular shapes (not all rocks are the same shape). Activity 2: Particle Size and Shape Because of the uniformly round shape of the marbles, they don’t pack together. Instead, they roll off each other. Same principle applies to animal feed – the more uniform and round the ingredients, the less likely the feed will pack together. This decreases the chance of feed handling problems. Activity 2: Particle Size and Shape For a feed that is fine (small) in particle size, it’s better to have a more uniform, round shape. Tendency of the small particles to pack together (like sand) is offset by their uniform, round shape which causes the particles to not pack together and roll off each other (like marbles). Proper balance between size and shape reduces feed handling problems. Activity 2: Particle Size and Shape Add a small amount of water to the cup of sand and the cup of rocks or marbles. Make castles again. Activity 2: Particle Size and Shape Water makes the sandcastle hold together even better, while the rocks or marbles still roll off each other. Activity 2: Particle Size and Shape The sand with water is a perfect example of what really fine grinding and added fat (moisture) will do in feed lines and feeders. Conclusion Animal nutritionists use their expert knowledge of particle size and shape and other propertie