Behavior of white leghorn laying hens after withdrawal of feed.

To approximate a commercially induced molt, feed was withdrawn (FW) from Hy-Line W-36 hens (65-wk-old) until they lost 35% of their initial body weight. Behaviors of 36 FW hens and 36 control hens were videorecorded on Days 1 to 3, 8 to 10, and 19 to 21 of FW, when FW hens reached 15, 25, and 35% body weight loss. The FW hens then were fed a pullet grower ration until Day 28 after the start of FW, whereupon they were provided a layer ration. Second cycle production of FW hens to 40 wk postmolt initiation averaged 15.5 dozen eggs/hen housed. The FW hens manifested increased aggression on the first d of FW, perhaps indicative of frustration, and then exhibited increased standing, head movement, and nonnutritive pecking on Day 2, followed by reduction of these actions on Day 3. Resting behavior was observed 24 and 40% of the time for FW hens on Days 8 to 10 and 19 to 21 of the FW period, respectively. Nonnutritive pecking was higher for FW hens than for control hens throughout the FW period. Preening was more frequent for FW hens on Days 8 to 10, probably due to skin sensitivity near the start of feather push out, which began on Day 11. Behavior during the feed withdrawal period was consistent with conservation of bodily reserves, but FW hens never lost their capability for alertness and reactivity. The FW hens had significantly lower mortality during the study than control hens (2 vs 12%, respectively).