The demand for straw and feathers as litter substrates by laying hens

Consumer demand theory has been applied to investigate behavioural demands and environmental requirements of farm animals. Recent research with laying hens has shown that the demand for various floor litters (peat, sand, wood-shavings) is inelastic. Other types of litter (e.g., straw and feathers) are available to laying hens in some housing systems. This study aimed to determine the importance of straw and feathers to laying hens by measuring demand functions for these items. In 1 h sessions individual birds (n = 6) were given the opportunity every second day to work on fixed ratio (FR) schedules (FR5 to FR200) for access to either straw or feathers. The number of responses made and reinforcers delivered was recorded, All birds worked to gain access to straw but only three worked for feathers. None of the hens dustbathed consistently in either litter. The mean elasticities of the demand were significantly different from zero and were -0.48 (s.e, 0.04; p < 0.001) for straw and -0.45 (s.e. 0.05; p < 0.001) for feathers. The results imply that even if a substrate does not stimulate dustbathing, caged laying hens have a high demand for a litter substrate. (C) 2000 Elsevier Science B.V. All rights reserved.