Sandpaper or rough shells
Description
The terms ‘sandpaper shells’ and ‘rough shells’ refer to eggs with rough-textured areas, often unevenly distributed over the shell.
Incidence
The incidence is normally less than 1% of total production, but may be higher for some strains of bird. It is also higher in early lay, often as a result of double ovulation, which produces one shell-less egg and another one with extra shell deposits.
| Cause | Control |
|---|---|
| Diseases, e.g. infectious bronchitis, infectious laryngotracheitis or avian encephalomyelitis | Follow effective vaccination programmes. |
| Defective shell gland Disturbances at the time a hen is due to lay can cause the egg to be held over for another day | Minimise activities which create disturbances in and around the shed. Increase shed security to stop other birds and animals entering the shed. |
| Incorrect or changes in lighting programme | There should not be sudden increases in day length as pullets come into lay, or lighting changes during lay. |
| Water shortages | Make sure that the water supply is adequate, that there are no blockages in water lines and that drinkers are functioning property. |
COPYRIGHT NOTICE: OPTIMUM EGG QUALITY - A PRACTICAL APPROACH
© The State of Queensland, Australia (through its Department of Primary Industries and Fisheries) and DSM Nutritional Products Ltd., 2007. No part of this publication may be reproduced, copied or transmitted save with prior written permission of Director, Intellectual Property Commercialisation Unit, Department of Primary Industries and Fisheries, GPO Box 46 Brisbane, Queensland, Australia 4001, and DSM Nutritional Products Ltd.
© The State of Queensland, Australia (through its Department of Primary Industries and Fisheries) and DSM Nutritional Products Ltd., 2007. No part of this publication may be reproduced, copied or transmitted save with prior written permission of Director, Intellectual Property Commercialisation Unit, Department of Primary Industries and Fisheries, GPO Box 46 Brisbane, Queensland, Australia 4001, and DSM Nutritional Products Ltd.