Two experiments were carried out with Holstein heifer calves to determine the effect of supplying a major portion of the protein in milk replacers by isopropanol-extracted protein concentrate from whole herring (FPC) or a mixture of FPC and soybean protein concentrate (SPC). Milk replacers were compared with whole milk in experiment 1. All calves were abruptly weaned when consuming 0.5 kg starter/day, or by 5 weeks of age. Calf performance was similar when the pre-weaning liquid diet was whole milk, or milk replacers containing either milk protein or 50% of the protein from FPC. Average daily gains to weaning and to 26 weeks of age for all calves were 377 and 692 g/day, respectively. Calves in experiment 2 were fed either an all-milk protein milk replacer or one containing 98% of the protein equally from FPC and SPC. Both milk replacers were fed once daily either six or seven times per week. Calf growth to weaning was lower on the FPC–SPC formula (283 vs. 364 g/day, P < 0.01), but was not significantly different (P < 0.05) to 15 weeks of age (618 vs. 643 g/day). Feeding milk replacer six vs. seven times per week had no significant effect on calf growth. Digestibility coefficients of dry matter, nitrogen, and energy were similar in bull calves fed the all-milk or FPC–SPC protein milk replacers, but retention of absorbed nitrogen was less on the latter diet (54 vs. 45%, P < 0.10).
A New Process for Preparation of Soybean Protein Concentrate with Hexane-Aqueous Ethanol Mixed Solvents
