Production performance and nitrogen flow of Shaver White layers housed in enriched or conventional cage systems

• Published in: Poultry science Vol. 90; no. 3; pp. 543 - 554
• Main Authors: Neijat, M, House, J.D, Guenter, W, Kebreab, E
• Format: Journal Article
• Language: English
• Published: Oxford, UK Poultry Science Association 01.03.2011; Oxford University Press
• Subjects: Animal Feed - analysis; Animal Nutritional Physiological Phenomena; Animals; Chickens - metabolism; Diet - veterinary; Eggs - standards; Feeding Behavior; Female; Housing, Animal; Nitrogen - metabolism; egg production; nitrogen balance; manure nitrogen; caging system
• ISSN: 0032-5791; 1525-3171
• DOI: 10.3382/ps.2010-01069

Despite the large number of studies examining the impact of cage systems on Ca and P nutrition, data are limited on the N balance of hens when housed under different systems. To this end, an experiment was conducted to assess N balance, manure characteristics, and indices of the performance of laying hens housed in 2 distinct caging systems. A total of 4,836 commercial Shaver White hens were housed in either enriched (EC) or conventional (CC) cages (average floor space per bird of 643 and 468 cm², respectively) under semicontrolled environmental conditions. Enriched cages provided hens with a curtained nesting area, scratch pad, and perches. Birds in both systems were phase fed similar layer diets for 11 periods (4 wk each). Data, expressed on a hen basis, were analyzed as repeated measures using the mixed model procedure of SAS. Lower feed disappearance (P < 0.01; 92.5 vs. 95.0 ± 0.6 g/d, DM basis) and manure output (P < 0.01; 79.8 vs. 91.3 ± 1.2 g/d, as-is basis, and 27.0 vs. 28.1 ± 0.2 g/d, DM basis) were observed in birds housed in EC compared with CC, respectively. Manure DM was 34.1 and 31.0 ± 0.3% for EC and CC, respectively. Egg production, feed conversion ratio, BW, egg weight, and egg mass were not significantly different between the 2 systems. Overall egg N output decreased with age for both cage systems and was not significantly different between the systems. Although no difference was observed in the overall manure N excretion (1.94 and 1.96 ± 0.02 g/d for EC and CC, respectively), hens housed in CC had a significantly (P < 0.05) higher N balance compared with those in the EC system (85.0 vs. 30.2 ± 13.6 mg/d, respectively), which could potentially be explained by a higher (P < 0.05) manure N excretion in the EC at the later stages of production. The current data provide estimates of the efficiency of N utilization in laying hens housed under different housing conditions.