A Comparison between the effect of( step- down and short constant ) light systems of pullets on some productivity indicators in laying hens. Damascus University Journal of agriculture sciences, [S. l.], v. 36, n. 2, 2021. Disponível em: https://journal.damascusuniversity.edu.sy/index.php/agrj/article/view/171. Acesso em: 18 jun. 2026.