A study of changes in fasting metabolic rate with duration of egg production in the domestic fowl

Synopsis The fasting metabolic rate (FMR) of six Warren SSL hens was determined at point of lay, peak production and post‐peak production (70 per cent). The results showed that the averages of the FMRs for the six hens during the first two periods were similar (3.12 and 3.06 kcal/h kg†), but that the post‐peak production average showed a marked increase in FMR to 3.75 kcal/h kg† indicating that the FMR of the laying fowl may not always be constant, and that an increase can occur after peak production.