|Cheng, Heng Wei|
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2002
Publication Date: 8/1/2002
Citation: CHENG, H., FREIRE, R. BEHAVIORAL RESPONSES TO INDUCED MOLTING IN LAYING HENS. POULTRY SCIENCE ASSOCIATION MEETING ABSTRACT. 2002. V. 80(SUPPL.1): ABSTRACT P. 102. Interpretive Summary:
Technical Abstract: Induced molting in laying hens by feed withdrawal (FW) has led to public concern regarding the well-being of hens. Behavioral changes in animals have been used to evaluate well-being and behavioral-managerial interactions. A total of 168 hens from Hy-line W-92 line (65 wk of age) were divided evenly into induced molting (IM) and control groups. IM hens were food deprived for eight days and kept on a 8h:16h (light:dark) lighting program, leading to a 30% loss in body weight. The control hens were fed on laying ration ad libitum. Behavior was measured as 7 mutually exclusive categories from video recording using instantaneous sampling at 1-minute intervals for 10 minutes each hour, starting at 0700 on Days -3 (pre-FW), 1, 3, 5, 8 (during FW), and 1 and 4 weeks (post-FW). During the FW period, IM hens exhibited increased pecking of the cage and other birds on Day 2 (ANOVA, P<0.05). Preening was greatest from Day 3 to 6 (ANOVA, P<0.01), largely at the expense of inactive standing (ANOVA, P<0.01). Behavior throughout the light period was reasonably constant, with the exception of preening which was lower in the two hours prior to lights-off (ANOVA, P<0.01). IM birds drank more than controls in the first week following the return of food (ANOVA, P<0.05), though no other significant behavioral differences between IM and controls were observed during this period. Surprisingly, time spent feeding was lower in IM hens than controls on Day 8 and 38 (t-test, P<0.01 and P<0.05 respectively) In contrast, IM hens spent more time preening (t-test, P<0.05) and standing (t-test, P<0.05) on Day 8 after the return of food. Results presented here suggest that the largest changes in behavior occur soon after food withdrawal, but most behavior is reasonably constant within a day during this period. However, more notable changes in behavior were found one week after food was returned, possibly due to development of the reproductive system and increased skin sensitivity caused by feather push-out.