Growth and Nutrient Utilization by Calves Fed Milk Replacers Containing Milk or Soybean Protein-Concentrate Heated to Various Degrees

Four groups of six Israeli-Friesian calves each, 7 to 10 days old, were fed on all-milk replacer-Milkvit, and heated, partly heated, and raw soybean milk replacers for 46 days. The calves fed raw and partly heated replacers did not grow while on these diets. The growth rate of the calves fed the heated replacer was 35% that of those fed the Milkvit control during the first 10 days and 95% after the first month. Heating improved the digestibility of the soybean protein from 72% for the raw to 79 and 88% in the partly heated and heated soybean replacer groups. Blood urea was highest in the raw and partly heated, intermediate in the heated soybean replacer group and lowest in the Milkvit-fed calves. Blood glucose was highest in the Milkvit group shortly after feeding, and lowest in the raw and partly heated soybean replacer groups. Soybean diets diminished markedly the incidence and severity of diarrhea. Soybean concentrate, when included in the diets of suckling calves, should be properly heated.