USE OF THE WILLEMS POLYTRON® TO HOMOGENIZE FAT AND DISPERSE INSOLUBLE INGREDIENTS IN HIGH-FAT LIQUID MILK REPLACERS

Abstract

The operation of the Willems Polytron® to prepare batches of high-fat (27–35%, air dry basis) milk replacers is described. Most milk replacers were mixed at 40% solids to minimize foaming, and were diluted prior to feeding. The Polytron homogenized fat in liquid mixtures at 55 or 65 C, and partially dispersed insoluble ingredients in soybean, rape-seed, and fish flours. The inclusion of 25% or more of partially delactosed acid whey powder increased the viscosity of the mixtures, and held insoluble ingredients in suspension for several hours. Homogenization of a milk replacer containing 73% skim milk powder and 27% bleachable fancy tallow (3% soybean lecithin added) markedly improved growth (425 vs. 190 g/day), dry matter, nitrogen, and energy digestion (92 vs. 73% for energy) and nitrogen retention (44 vs. 24%) by calves. Calf responses were similar when the liquid diet was homogenized at either 55 or 65 C. Homogenization with 3% soybean lecithin in the tallow increased digestion of dry matter, nitrogen, and energy by chives by 5–6% units (P < 0.2), and Ca by 16% units (P < 0.05) compared with no lecithin. Bleachable fancy or crude tallow and 3% soybean lecithin or 0.2% glyceryl monostearate in the fat gave similar calf responses.