|Pohle, Kim - PURDUE UNIVERSITY|
|Cheng, Heng Wei|
Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: June 18, 2004
Publication Date: July 25, 2004
Citation: Pohle, K., Cheng, H. 2004. Housing effect of behavior & physiology during a feed-withdrawal molt in laying hens: Furnished cages vs. conventional cages. Poultry Science. 83(S1):361. Technical Abstract: Environmental variations affect an animal's response to stressors. This study examined whether an enriched environment can reduce hens' stress responses during feed-withdrawal induced-molting which has been identified as a managerial stressor to laying hens. At 19 wk of age, White Leghorn hens were randomly assigned into conventional cages at 6 hens per cage (645 cm2 of floor space/hen), or furnished cages at 10 hens per cage (610 cm2 of floor space/hen). Furnished cages contained nests, perches, scratch pads, and dust baths (Big Dutchman, Germany). Feed-withdrawal induced-molt was initiated at 72 weeks of age. Feed was withdrawn on Day 0, cracked corn was returned on Day 7, diet was changed to pullet feed on Day 14, and then to layer ration on Day 21. Physiological data was collected via blood collection on days -13, 0 (prior to feed withdrawal), 1, 5, 7 (prior to feed return), 14, and 35, including serotonin, epinephrine, norepinephrine, dopamine, and corticosterone levels, and hematological parameters. Behavioral data were collected on days 0, 2, 4, 6, 8, 9, and 17 using continuous observation from 0900-0930 and 1430-1500. There were no significant differences between furnished and conventional cages in overall hormone levels and heterophil:lymphocyte ratio during the molting period (ANOVA, P>0.05). Behavioral observations during the feed withdrawal period indicated that hens in conventional cages spent more time sitting on the cage floor than hens in furnished cages (ANOVA, P=0.04). Hens in conventional cages also spent more time inactive than hens in furnished cages (ANOVA, P=0.005). Hens in both conventional and furnished cages increased their time spent preening (ANOVA, P=0.004) and exploratory pecking (ANOVA, P<0.001) following feed withdrawal. Hens housed in the furnished cages, compared to their behaviors before the treatment, increased dust bath usage (ANOVA, P= 0.01) during the feed withdrawal period. These results indicate that housing conditions do not fully compensate for the physiological stress induced by feed-withdrawal induced-molt.