Differential response of dairy cows to supplementary light during increasing or decreasing daylength

behaviour body condition body weight bovin cattle comportamiento comportement comportement alimentaire corticoides corticoids dairy cows feed intake feeding habits fotoperiodismo ganado bovino glucocorticoides glucocorticoids housing hydrocortisone letargo light light regimes lighting logement luz milk production milk yield peso corporal photoperiodicity poids corporel prise alimentaire (animaux) regimenes de luz rendement laitier rendimiento lechero repos rest somatic cell count vacas lecheras vivienda