Behavioral Activities and Energy Expenditure of White Leghorn Laying Hens under Day-Night Cyclic Temperatures

Abstract

Single Comb White Leghorn laying hens (Hyline) were fed ad libitum in order to estimate energy expenditure of behavioral activities (BA) such as standing, eating or body movements et cetera under artificial day-night cyclic ambient temperatures (Ta) 33-25°C, 25-33°C and constant Ta 29-29°C. The light (12h)-dark (12h) periods synchronized with the Ta, commencing at 09 : 00. Body movement of the hens was detected by the Actigraph as activity count (ACT), while standing time (STN) et cetera were measured by the infra-red beam switches. Heat production (HP) was measured by the indirect calorimetry. HP, ACT and STN of each hen were measured continuously for 48h. The daily food intake (FI) of the hens were in a decreasing order at 29-29°C, 25-33°C and 33-25°C, respectively. On the other hand, the daily HP were in a reverse order of FI at 29-29°C, 25-33°C and 33-25°C, respectively. As the ACT and STN increased significantly during the dark periods under higher Ta, this may have induced higher HP. Energy expenditure of BA when expressed by the ACT were 19%, 22% and 30% of the daily HP at 33-25°C, 29-29°C and 25-33°C, respectively.

Keywords

• behavioral activities
• energy expenditure
• cyclic temperature
• laying hen