Fatness of laying hens and induced moulting regimens

Abstract
1. A flock of laying hens was divided into two groups according to their fatness, which was estimated using abdominal fatness callipers. 2. A moult was induced in both groups by reducing day‐length and restricting food intake. The food restriction period lasted for 2, 3 or 4 weeks and the birds were given either 15 or 25 g of whole wheat/bird. 3. No differences were observed between the moulting treatments on post‐moult egg weights, shell strength or Haugh units, but maximum egg output (g/bird d) was obtained by the 4‐week food restriction period for the fat‐grouped birds but by the 3‐week food restriction for the lean‐grouped birds. 4. The birds restricted to 15 g wheat/bird d showed a more rapid regression of the ovary and oviduct, which may account for their increased egg numbers towards the end of the 22‐week laying period compared to the birds allocated 25 g/bird d.