title: The postrest performance of laying hens subjected to early or late water restriction during the feed withdrawal period.
abstract: Two experiments initiated in December and April were conducted to determine the effect of water restriction on the performance of force-rested hens. Birds used in this study were housed in cages and were 74 weeks of age at the beginning of each study. Treatment assignments were 1) no water restriction, 2) water restriction on Days 1 and 2 (48 hr), and 3) water restriction on Days 9 and 10 (48 hr). All birds were subjected to identical 10 day feed withdrawal periods, were fed low protein and low calcium recovery diets to Day 35, and then were placed on a standard postrest feeding system for six 28-day production periods. With only three exceptions, within-experiment differences in postrest performance due to water restriction treatment were not significant regardless of criteria evaluated or season of force-rest initiation. When water was restricted on Days 9 and 10 in the experiment initiated in April, hens laid at a significantly lower rate with significantly heavier eggs than others in the same experiment. Hens that experienced either water restriction treatment during the April force-rest had poorer feed conversion when expressed in terms of egg numbers. Feed intake, feed conversion on a weight-for-weight basis, egg specific gravity, and mortality were not affected by water restriction treatment, regardless of season. Water restriction was not necessary for a successful force-rest of laying hens, and, in fact, could be detrimental when instituted in the later part of the feed withdrawal period in warm weather.
mesh_terms: D000818:Animals; D002645:Chickens / Q000502:physiology*; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D010058:Oviposition; D014868:Water Deprivation / Q000502:physiology*