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Correlation of Eggshell Quality with Tibia Status and Other Production Parameters in Commercial Leghorns at Oviposition and 10 Hour Postoviposition

1990; Elsevier BV; Volume: 69; Issue: 12 Linguagem: Inglês

10.3382/ps.0692068

1525-3171

J. I. Orban, D.A. Roland,

Rabbits: Nutrition, Reproduction, Health

The relationship of eggshell quality to tibia status and production parameters in laying hens was evaluated in three trials. Hens were fed commercial-type layer diets for 12 wk, and data were collected for evaluation during the last 2 wk of egg production. Hens were killed at oviposition and 10 h postoviposition, and tibiae were removed to determine tibia status, tibia weight, tibia strength, and percentage bone. Eggs collected were used to determine shell quality, shell weight, shell thickness, shell strength, percentage shell, and specific gravity. There was no relationship between shell quality and tibia weight or tibia strength at oviposition. Percentage bone, however, was negatively correlated with shell quality (specific gravity, −.308; shell weight, −.363; and percentage shell, −.265). At 10 h postoviposition, tibia strength was negatively correlated with shell quality (specific gravity, −.184; shell weight, −.195; percentage shell, −.187) for birds with a shell-less egg in the oviduct. This negative relationship was also seen when birds had no egg in the oviduct (tibia strength and specific gravity, −.501; tibia strength and shell weight, −.181; tibia strength and percentage shell, −.160). Results indicate a relationship between shell quality and tibia status during eggshell formation, suggesting possible resorption of the cortical bone of tibia in conjunction with the medullary bone during eggshell calcification.