Feather pecking and dietary protein

摘要

Feather pecking and cannibalism in laying hens remain a serious welfare and economic problem in tile egg industry. Pecking damage occurs as unpredictable outbreaks, particularly in non-cage systems. Its consequences can range from minimal feather damage to serious feather loss, injury anti mortality. Despite numerous investigations, the causation of this damaging behaviour is not fully understood, although factors such as lighting, stocking density, group size, rearing environment and genetic predisposition have all been implicated. In recent years, it has been suggested that increasing levels of pecking damage might be causally related to the increased reliance on plant protein sources for layer diets. This has been due to restrictions imposed by some retailers, the relatively high cost of fishmeal, and the recent ban on the use of meat and bone meal. Anecdotal reports from egg producers have suggested that inclusion of animal protein (in particular fishmeal) Can be effective in preventing or halting outbreaks of damaging pecking once they have begun. The, notion that animal protein could be beneficial was expressed by the UK Farm Animal Welfare Council in its 1997 Report on the welfare of Laying Hens, where they suggested that "lack of animal protein in the diet predisposes tile flock to injurious pecking leading to cannibalism and death". They recommended "further research work to identify and quantify the factors in animal protein responsible for reducing injurious behaviour in laying hens". However, there is currently no experimental evidence demonstrating a beneficial effect of animal protein on pecking damage, and the alternative possibility of a detrimental effect of plant protein sources has been ignored. Soya bean meal, for example, is a rich source phytoestrogens, and it is conceivable that these biologically active compounds could have an effect on behaviour. To address these questions, at study was carried out at Roslin Institute (Edinburgh), to investigate experimentally whether dietary protein source (animal or plant) had any effect on tile development of feather pecking and cannibalism in layer pullets.