The energy requirement for maintenance and production of laying hens.

Abstract

Heat production was recorded by open-circuit respiration calorimetry. In the first 3 experiments heat production after 24 h without feed by birds laying at about 80% production was measured. Mean daily fasting heat production of 12 White Leghorn hens of 1.68 kg bodyweight caged individually, 12 White Leghorn hens of 1.68 kg caged in pairs and 10 Australorp x Rhode Island Red hens of 2.4 kg caged in pairs were 97.0, 98.0 and 90.6 kcal per kg W^0.75. The overall relation between heat production (H) and W^0.75 was H=85.2 W^0.75+16.6. The relation between daily energy retention (Y) in kcal per kg W^0.75 and intake of metabolisable energy (ME) (X) in kcal per kg W^0.75, established with 37 White Leghorn hens at peak and end of production, after 12 months, was Y= 0.642 X-65.7. The net availability of ME for egg production was 64.2+or- 5.5% and the daily maintenance requirement was 102+or-7.6 kcal per kg W^0.75. The result was applied to a laying trial with 1020 hens in batteries and 300 on deep litter to get a measure of ME used for maintenance. After subtraction of ME used for production the calculated mean for maintenance was 131 and 138kcal per kg W^0.75 for hens in batteries and on deep litter. ME for maintenance was greater in winter.-D. W. F. S. (Abstract retrieved from CAB Abstracts by CABI’s permission)