Effects of hydrolyzed spray dried red blood cells in milk replacer on calfintake, body weight gain, and efficiency

An alternative protein ingredient based on spray-dried, hydrolyzed red bloo d cells was evaluated in calf milk replacers. Two experiments were conduced to determine the value of the ingredient on intake, growth, and feed effic iency in dairy calves. In experiment 1, Holstein bull calves (n = 120) were fed calf milk replacer containing 0, 11, 22, or 43% of crude protein as sp ray dried hydrolyzed red blood cells. Calves were fed 454 g/d of experiment al milk replacer reconstituted to 12% dry matter plus a conventional calf s tarter for 28 d. Body weight gain, intake of milk replacer and calf starter , feed efficiency, fecal scores, and days scouring were unaffected by sourc e of protein. In experiment 2, Holstein calves (n = 69) at the University o f Minnesota, Crookston and Waseca were fed milk replacer containing 0, 22, or 43% of crude protein as spray dried hydrolyzed red blood cells. Calves w ere fed 454 g/d of experimental milk replacer reconstituted to 12% dry matt er plus a conventional calf starter containing 0 or 25% alfalfa meal for 35 d. No calves died during the study. Body weight gain, feed efficiency, int ake of calf starter and milk replacer, fecal scores, and days scouring were unaffected by increasing hydrolyzed red blood cells in milk replacer. Simi lar performance of all calves indicated that spray dried hydrolyzed red blo od cells can replace up to 43% of crude protein from whey protein concentra te without detrimental effects on animal performance.