2120 final report.pdf - Agra CEAS Consulting

APPENDIX 2: THIRD COUNTRIESA2.4.2.3. Technical dataRaising pullets:Most flocks originate as day-old chicks that are brought to the grow-house for raising. A single layercage may contain as many as fifty chicks 157 . As they mature, the cage density is reduced. Usuallyduring the first week, beaks are trimmed. The period of light is reduced sharply over the first fourweeks and then more gradually. Feeding rations are adjusted over the period to promote fulldevelopment of the pullet in preparation for laying. Genetics companies provide detailedrecommendations on the ration to be fed to their breeds at different stages of the bird’sdevelopment. It is common for at least four different rations to be fed during the grow-out period.At an age of 17 to 18 weeks, pullets are moved to lay-houses.Large-scale commercial systems:Given their dominance of the U.S. egg industry, it is the large-scale commercial production systemsthat are of central interest to this study. Among these production systems, the principal differencelies in whether producers engage in molting and, if they do, the number of times they molt theirflocks. Historically, layers began producing at about 20 weeks of age. With the more rapidlymaturing strains that have been developed in recent years, production now begins at 16 to 18 weeks.Peak production now occurs around 24 to 26 weeks, compared to 32 weeks in the past. As flocksnear about 70 weeks of age, egg production slows and, depending on the price of eggs and the costof feed and pullets, approaches break-even for the producer. At this point, producers have twochoices. They can either send their hens to slaughter, replacing them with a new flock of pullets, orrecycle the existing flock by inducing a ‘molt’.Traditionally, molts are induced through reduced lighting and removing feed for 10 to 14 days,followed by the use of a special feed formulation for several days. For a period of two to four weekswhile molting, egg production drops to zero. With the removal of feed, birds lose 30% to 35% oftheir weight and drop at least a portion of their feathers. Mortality rates usually accelerate duringthe molt, though it is generally recommended that mortality rates not be allowed to exceed 1.25%during the period that feed is withheld. With the resumption of feeding and reintroduction oflighting, the birds gain weight and resume laying.Within 8 to 12 weeks after the molt is initiated, birds return to production and generally reach apeak egg production of 80% to 85% (compared to a peak of 85% to 95% during the first cycle).Production at this level does not continue long and falls to around 50% within 30 to 40 weeks afterthe molt was initiated.At this point, with production again approaching break-even, producers must decide whether to sendtheir flock to slaughter or to induce a second, and final molt. If molted for a second time, hensreturn to production for a period of about 30 weeks before being sent to a spent hen facility.157 While essentially all layers in the U.S. are housed in cages, around one-fifth (21%) of these layers were floor reared as pullets. SeeUSDA, APHIS, Layers ’99, October 1999.375