THE EFFECT OF ALFALFA AS A SOURCE OF FIBER IN STARTER DIETS FOR HEIFER CALVES

Abstract

Starter diets were formulated to contain 6.6, 12.4, 17.7 and 21.9% fiber by the addition of 0, 20, 40 and 60% reground dehydrated alfalfa to a barley-based concentrate. Sixty Holstein heifer calves were randomly assigned at birth to one of these four diets which were fed free choice from 7 to 70 days of age. Whole milk was fed at 10% of body weight from birth to 56 days. Dry matter intakes were 0.47a, 0.59ab, 0.61b and 0.60ab kg/day and body weight gains were 0.44a, 0.58b, 0.69b and 0.56ab kg/day for diets containing, 0, 20, 40 and 60% alfalfa, respectively (means followed by a common letter are not significantly different (P < 0.05)). Diet did not influence blood components except for blood urea nitrogen which was higher for calves fed diets containing 40 and 60% alfalfa. The amount of fiber in the diet did not influence the incidence of scouring or other disorders. Calves which had scoured for 2 or more days had reduced rates of gain and feed efficiency compared with heifers that did not scour. Dry matter digestibility, as estimated by total fecal collections from six bull calves per diet, was 85.4, 78.7, 73.7 and 75.1 for the diets containing 0, 20, 40 and 60% ground dehydrated alfalfa, respectively. Key words: Alfalfa, dairy calves, digestibility, scours, feed efficiency