Development of pecking damage in layer pullets in relation to dietary protein source.

1. In recent years, the UK egg industry has become increasingly dependent on plant protein sources, in particular soyabean meal, and it has been suggested that this trend (and/or the concomitant absence of animal protein in layer diets) might be causally related to increased feather pecking and cannibalism. 2. This study examined the development of pecking damage in relation to dietary protein source, by rearing 12 groups of 12 layer pullets to 24 weeks of age on diets based on 'animal' (fishmeal) or 'plant' (soyabean meal) protein. 3. Damaging pecking began at 6 weeks of age, in three groups (one plant and two animal). Injurious pecking began at 18 weeks of age, and affected four groups (two plant and two animal). 4. Greater numbers of vigorous pecks/pulls were observed in plant protein groups throughout the experiment, although they were significantly higher only between 13 to 16 weeks of age. Pecking damage scores did not differ between treatments. 5. Dietary protein source did not affect plasma oestradiol, progesterone or egg production. 6. These results do not support the notion that inclusion of fishmeal in laying hen diets prevents or alleviates feather pecking and cannibalism.