EFFECT OF ADDED BULK ON GROWTH, NUTRIENT UTILIZATION, DIGESTIVE SYSTEM AND DIARRHEA IN CALVES FED MILK REPLACER

Liquid milk replacera with or without added sawdust, purified wood cellulose or oat hulls (3% of dry replacer), or whole milk were fed to dairy calves in metabolism cages to study growth, digestibility, physical, chemical and enzymatic changes in the digestive tract, and incidence of diarrhea. In a relatively draft-free room at 21–22 °C bulk tended to increase 1 fecal dry matter (19.6 vs. 17.1%). Bulk, especially oat hulls, also tended to reduce incidence of diarrhea compared with milk replacer fed alone. Bulk had no effect on calf growth, digestibility of milk replacer nutrients or nitrogen retention. Oat hulls were the only bulk source which entered the rumen, causing development of this organ, and increasing the percent dry matter and lowering the pH of abomasal contents. It was concluded that bulk, especially in the rumen, may exert a beneficial effect on the digestive tract of calves consuming only milk replacer.