Effects of restricted feeding on physiological stress parameters in growing broiler breeders

Abstract

This study investigated the effects of food restriction on stress levels in growing broiler breeders. The researchers measured plasma corticosterone concentrations, heterophil:lymphocyte (H/L) ratio, body temperature, heart rate, and activity levels in both restricted and ad libitum-fed birds. Results showed that restricted birds exhibited higher corticosterone levels and a stronger stress response to manual restraint, indicating higher stress levels. Furthermore, restricted birds displayed a clear diurnal rhythm in body temperature, heart rate, and activity, while ad libitum-fed birds had a blunted rhythm. The researchers suggest that differences in metabolic rate and stress levels may contribute to the observed physiological differences between the two groups. They emphasize the importance of using a combination of behavioral and physiological parameters for a comprehensive assessment of stress in growing broiler breeders.