Protein and Fat Sources in Milk Replacer for Calves

Abstract

The chemical composition and solubility of milk replacers substituted milk protein by plant or animal protein were studied in experiment I. Five experimental diets included the control diet (diet 1), utilizing 100 % crude protein from milk protein, and the test diets in which 30 % of milk protein was replaced by full fat soy flour, extruded soybean meal, fish meal and egg powder for diet 2, 3, 4 and 5, respectively. There was little difference in chemical composition, except the diet 5 which contained more ether extract than the other diets. Solubility value of diets 1, 2, 3, 4 and 5 were 93.77, 91.67, 86.80, 89.44 and 93.44 %, respectively (P<0.05). The effects of water temperature 30-50°C on solubility were significantly higher than that of 60- 90°C (P<0.05). The experiment II was to study the effect of fat source (butter fat, BF; tallow, T; soya bean oil, SBO; palm oil, PO) on the rancidity of milk replacer utilizing various protein sources (milk protein, M; full fat soy flour, SF; fish meal, FM). Twelve experimental diets consisted of (1-4) 100 % crude protein from M with the following fat sources of BF, T, SBO and PO respectively; (5-8) 70 % crude protein from M and 30 % from SBO with the following BF, T, SBO and PO as fat source respectively; (9-12) 70 % crude protein from M and 30 % from FM with the following fat sources : BF, T, SBO and PO respectively. Peroxide value was measured as the results of rancidity of milk replacers every week for 16 weeks. The results showed that the rancidity of diet 3, 7 and 11 occurred at the 11th week; while diet 12 occurred at 12th week ; diet 4, 8, 9 and 10 occurred at 13th week ; diet 1, 2, 5 and 6 occurred at 14th week. Milk replacers used M+FM as a protein source were higher of peroxide value than the diets used M and SF as the proteins source. And the diets used M+FM and M+SF as a protein source were higher of peroxide value than the diets used only M.