Effect of Feedbunk Stocking Density on Weight Gains and Feeding Behavior of Yearling Holstein Heifers

Abstract
Linear feedbunk space for yearling Holstein heifers was altered by assigning 6, 12, 18 and 24 head to feed from a 4.88 m feedbunk to yield 0.81, 0.41, 0.27 and 0.20 m of feedbunk space/head. Each treatment group was fed to yield 0.75 kg average daily gain for two 45 day periods. Heifers were weighed every 45 days, and their feeding behavior was recorded on video tape for 2 of every 45 days. Precentage of heifers able to feed from the feedbunk at 1 time and the average daily gain for the 0.81, 0.41, 0.27 and 0.20 m groups were 100%, 0.82 kg; 100%, 0.66 kg; 67%, 0.72 kg; and 50%, 0.47 kg. The groups spent 4.82, 4.72, 4.30 and 3.55 h/day per head eating from the feedbunk. Heifers in the 0.20 m group consumed all feed in the bunk within 14 h after feeding. Lowering the feedbunk space to 0.20 m/head reduced average daily gain and total eating time/day. Feedbunk space/head of 0.27 m is required to insure adequate daily gains with yearling Holstein heifers under restricted feed intake.