Agonistic Behavior and Egg Production of Caged Layers: Genetic Strain and Group-Size Effects ,

作者：B.A. Al-Rawi, James V. Craig, A.W. Adams · 发表于：Poultry Science · 年份：1976 · DOI：10.3382/ps.0550796 · 被引用次数：64 · 研究领域：Animal Behavior and Reproduction、Animal Nutrition and Physiology、Animal Behavior and Welfare Studies

We housed 5 commercial strains of 20-week-old White Leghorns in groups of 4, 8, and 14 birds per cage; each subclass was represented in each of 5 rows of colony cages. Area, feeder, and water space per bird were held constant for all group sizes. Agonistic behavior, age at sexual maturity, hen-day rate of lay, hen-housed egg production, mortality, and egg quality were evaluated over 40 weeks of production. Results indicated significant differences among strains in aggressiveness. Birds in the larger groups interacted more than they did in groups of 4. Pecking was more frequent than threatening; birds interacted more during ingestion than when engaged in other activities. Egg production and quality traits and mortality were affected by genetic stocks. Increasing group size depressed egg production and increased mortality. Birds in larger groups spent less time in ingestive behavior. Egg quality traits were not altered by group size. Considerable differences were found for all traits during different periods (ages). No associations were found between frequencies of agonistic acts by flocks and their egg production or between social status of individuals and duration of time feeding. We found no convincing evidence in this study that overt agonistic behavior has any measurable effect on productivity in colony cages.