Submitted to: Poultry Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/24/2007
Publication Date: 9/1/2007
Citation: Anderson, K.E., Jones, D.R., Davis, G.S., Jenkins, P.K. 2007. Effects of Genetic Selection on Behavioral Profiles of Single Comb White Leghorn Hens Through Two Production Cycles. Poultry Science. 86:1814-1820. Interpretive Summary: Three historic strains and one current strain of commercial laying hens were compared for differences in behavioral profiles during a complete production cycle, including a molt. A molt occurs in the commercial egg production industry when daylength is decreased and nutritional intake is modified in such a manner that egg production ceases and the feather coat is shed. These factors are then reversed to allow the regeneration of a new feather coat and egg production resumes. Comfort and appetitive behaviors along with aggressive and fearfulness acts were monitored. All birds were maintained in standard commercial laying hen industry confinement. It was found that stage of production had the greatest effect on bird behavior. Genetic selection for enhanced production traits does not appear to have an effect on hen well-being or behavior.
Technical Abstract: Four layer genetic stocks consisting of three Ottawa Control strains 5, 7, and 10 and the H&N 'Nick Chick' (CCS) were utilized to evaluate potential changes in behavioral profiles due to the effects of genetic selection over time and molting. The behavior study consisted of 2 replicates from each strain. Each replicate consisted of 4 cages with 6 hens/cage. Behavioral observations were recorded on two consecutive days beginning at 22 wk of age and every 28 d thereafter during the 1st production cycle, the molt period, and the 2nd production cycle through 90 wk of age with concurrent feather and Hansen's Test scores recorded. Behavior profiles were similar between the control strains and the CCS. This indicates that genetic selection to enhance production parameters had no impact on behavior patterns. Appetitive behaviors were not affected by strain, but were affected by production phase and molting. During the molt, hens had reduced (P < 0.05) feeding (FD) and drinking (DR) frequencies to compared to those observed during the 1st and 2nd cycles. The data indicated that hens pecked inedible objects at a greater (P < 0.0001) frequency during the 1st cycle and molt than during the 2nd cycle. Strain or production phase did not influence the frequency of aggressive and submissive acts. Fearfulness scores were only influenced by production phase with the molt having the highest (P < 0.01) score of 3.46. Behavioral acts during molt are consistent with conservation strategies and appear to be consistent with fasting behaviors during anorexic states.