Preference and acceptability of four protein sources by ruminating Holstein calves

Abstract

Four successive groups of four calves each (~ 4 mo old) were individually penned and observed during a 14 d trial period for choice of concentrate. Prior calf diets contained soybean meal (SBM) (for two groups and distillers grains in place of SBM for two groups. Concentrates contained approximately equal amounts of corn with either SBM, peanut meal (PNM), fish meal (FSM), or corn gluten meal (CGM). Each day of four trials, .45 kg of each concentrate was randomly assigned to one of four equal feed box sections. Calf feeding position was recorded every 30 sec for no more than 50 min or until calves stopped eating. In addition, 1.36 kg of first cutting orchardgrass hay was offered twice per day. Measurements of amount of each feed consumed, order of consumption and length of time spent eating each feed were analyzed statistically to determine preference. Overall preference was for SBM, closely followed by PNM, both over FSM and CGM, with the l preference status of FSM showing the most change over time by decreasing throughout the trial periods. Neither section in which feed was offered nor previous experience with SBM significantly influenced preference. In addition, twenty calves ranging in age from 4 mo to 7 mo were divided and housed in four groups of five and observed during a 30 d trial period for acceptability of the protein feeds tested for preference. Acceptability, measured subjectively as length of time required by calves to eat each feed, was greatest for SBM, closely followed by PNM and CGM, and least for FSM. Analysis of calf weight gain showed no differences between feeds.