EFFECT OF FEEDING A CONCENTRATED WHEY-CANOLA MEAL MIXTURE AS THE MAJOR COMPONENT OF STARTER RATIONS FOR CALVES

Abstract

Thirty-two male Holstein calves were subdivided into four groups at 35 days of age and used to evaluate the feeding of an evaporated whey-canola meal feedstuff (EWC) fed in combination with either a grain-based starter ration or chopped hay. Over a feeding period of 7 wk, dry matter intake of EWC increased to 84 and 90% of total dry matter intake for the grain-based and hay-based starter rations, respectively. Rumen fluid butyrate and valerate levels increased to 40% and 15%, respectively, of total volatile fatty acids produced. Plasma urea levels were lower and phosphorus, potassium and copper levels were higher when EWC was fed. The digestibility of EWC-based diets was higher than either grain or hay diets without EWC. Nitrogen, calcium, sodium and potassium balances were substantially increased by the EWC-based diet. Bloat was a problem when the EWC was fed in conjunction with a grain-based starter ration. This problem was prevented by feeding small amounts of chopped hay. It was concluded from the results of this study that EWC could be fed in combination with chopped hay at up to 90% of the total dry matter intake of young calves without causing acidosis or digestive upsets. Key words: Whey, canola meal, starter rations, calves