Quality of Protein in Milk Replacers for Young Calves. V. Effect of Method of Dispersing Fat on Curd Formation and Whey Syneresis

Abstract

Studies were to determine the effect of fat dispersion methods on the ability of milk replacers to form firm rennet curds. Firm abomasal coagulums appear to be required by neonatal calves for good growth and health. Homogenizing fat into reconstituted skim milk with either a two-stage dairy homogenizer or a Polytron produced products yielded a soft curd and poor whey syneresis, similar to the soft curd from highly heated skim milk powder or homogenized whole milk. Low-pressure dispersion of fat at 20% and 50% of total solids produced milk replacers with markedly firmer curd and more syneresis than homogenized products. Higher concentrations of total solids enhanced curd strength at all percents of fat and for all dispersing methods.Dispersing fat into whey rather than skim milk yielded a stronger curd and more whey syneresis in milk replacers containing a mixture of skim milk and whey (60:40 ratio) and 20% fat in the dry matter.When milk coagulates in the stomach of the calf, the curd shrinks and expells whey (undergoes syneresis). A test for syneresis may be useful in evaluating milk replacers because more syneresis means quick formation of the typical firm curd containing fat and casein.