THE ABSENCE OF NEUROMAS IN BEAKS OF ADULT HENS AFTER CONSERVATIVE TRIMMING AT HATCH

Objective To determine the effects of the amount of beak removed and c auterisation time on neuroma formation in hens. Design A pathology stu dy with controls. Animals Twenty domestic fowl were beak-trimmed. Thre e non-beak-trimmed domestic fowl were used as controls. Procedure Beak s of two age groups with two levels of beak removal and either 2 s or 4 s cauterisation, were investigated macroscopically and microscopical ly for deformities. Results Scattered trauma-associated neuromas were present in the beaks of pullets 10 weeks after moderate trimming at ha tch, Neuromas were not present in beaks of adult hens that had been si milarly trimmed. Sensory corpuscles were present 10 and 70 weeks after moderate trimming, though fewer in number than in intact control hens . In contrast, trauma-associated neuromas persisted in beaks of 70-wee k-old hens that had been severely trimmed at hatch. A range of deformi ties that were absent in moderately trimmed, hens, were observed in he ns with severely trimmed beaks. Receptors were not seen in severely tr immed beaks. Conclusion Beak-trimming al hatch induces the formation o f neuromas, regardless of the amount of tissue removed. There is a cri tical amount of beak tissue that can be removed, beyond which trauma-a ssociated neuromas will not resolve, but will persist in mature hens.