Ключевые слова: agriculture, animals, avian, beak, bird, birdcage, cage, captivity, chicken, closed, cockerel, cockscomb, confined, coop, crest, crowded, egg, farm, feather, flock, flu, food, group, head, hen, looking, mesh, nature, pen, poultry, pullet, red, rooster, rural, staring, tot, trapped, virus, white, wire,