Beak-Trimming Effects on the Behavior and Weight Gain of Floor-Reared, Egg-Strain Pullets from Three Genetic Stocks During the Rearing Period ,

At 4 wk of age, White Leghorn pullets from three genetic stocks were divided equally into two groups for beak treatment. One group had half of the upper mandible and less of the lower mandible removed. For pullets in the other group, the beaks were kept intact. Chicks of the six combinations of stock and beak treatments were kept separately in two pens each. A sample of pullets from each of the 12 pens was marked, observed, and then weighed on Days 1, 7, 14, and 21 after beak-trimming and at 16 or 18 wk of age. The amount of feed consumed per pen was determined weekly from 4 to 7 wk. The stocks differed in terms of the percentage of time spent standing and crouching. The beak-trimmed pullets pecked less at the feed, delivered fewer pecks of all kinds, stood and crouched more, and showed more comfort activity than the birds with beaks intact. The pullets with the trimmed beaks gained 90% as much weight as intact-beak pullets during the first 3 wk after treatment and used 88% as much feed. During the 1st wk after the beak treatment, the relative weight gains and amount of feed consumed were even less for the beak-trimmed birds. However, by 18 wk of age, there was no difference in BW between the two groups of pullets. Interactions for beak treatment by age were found generally in both behavioral and performance traits. The initial differences between the beak-trimmed and intact-beak pullets tended to diminish with age. No differences were present at 16 or 18 wk of age, except for a continued lower frequency of litter-pecking by the beak-trimmed pullets.