Avian and Poultry Biology Reviews 15 (1), 2004

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The electroencephalogram and sleep in the domestic chicken

Takanori Ookawa*
Formerly Department of Physiology, Gifu University School of Medicine, Gifu, Japan

ABSTRACT

Recent electroencephalographic studies on the surface and subsurface of the chicken striatum confirmed that there is a marked correlation between the electroencephalogram (the EEG) and behavioural states of the chicken during wakefulness and sleep. An asymmetrical EEG pattern was recorded from the surface and subsurface of the chicken telencephalon. The chicken EEG changes are essentially similar to those of mammals, though the sleep spindles observed in mammalian neo-cortex are lacking in the chicken cerebrum. Birds exhibit a unique behavioural and electrophysiological state called `unihemispheric sleep' in which one cerebral hemisphere is awake and the other is sleep. This finding identified electro- encephalographically that the optic nervous fibres undergo a complete dicussation in birds. Chicks blinded by bilateral optic enucleation retain the ability to develop normal growth.The EEG associated with sleep was characterised by high amplitude and slow waves, and by low voltage fast waves, that is, paradoxical sleep in blinded chickens. During wakefulness, the EEG of blinded chickens shows the arousal pattern. The classification of stages from wakefulness to sleep has not yet been fully established in the birds.

Keywords: sleep, electroencephalogram, domestic chicken

Avian egg antibodies: basic and potential applications

Jennifer Kovacs-Nolan and Yoshinori Mine*
Department of Food Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada

ABSTRACT

The existence of an IgG-like molecule in avian eggs, referred to as IgY, has been well documented, and extensive research has been carried out on its characterization, production and purification. Although it is the functional equivalent of mammalian IgG, themajor serumantibody found inmammals, IgY is structurally different, and has been found to exhibit several important differences when compared to mammalian antibodies, including its physico-chemical properties and immunological capabilities. Recently, considerable researchhas focussedontheuse of IgYas analternative tomammalianantibodies for several applications, including for immunotherapeutic applications, especially for the oral passive immunization against various bacteria and viruses. Much researchhas also been carried out on the use of IgYas a replacement for IgGin various immunodiagnostic and immunoaffinity purification purposes.The use of IgYoffers several advantages over polyclonal antibodies produced inmammals, including providing a muchmore hygienic, cost efficient, convenient, humane and plentiful source of antigen-specific antibodies.

Keywords: avian, egg yolk, antibody, IgY, pathogens, stability, isolation, avian immune system, immunotherapy, diagnostics, af®nity chromatography

Beak trimming in chickens: historical, economical, physiological and welfare implications, and alternatives for preventing feather pecking and cannibalistic activity

M. J. Jendral* and F. E. Robinson
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada, T6G 2P5

ABSTRACT

Beak trimming is a commonly practiced procedure in the poultry industry and usually involves partial amputation of the upper and lower beak. Beak trimming is performed to reduce mortality and production losses associated with feather pecking and cannibalistic behaviour.Although the procedure is traumatic andmay cause acute and chronic pain, the consequences of feather pecking and cannibalistic activity may be more detrimental to birdwelfare than the act of beak trimming.This reviewaddresses the predisposing factors for feather pecking and cannibalism, and the historical and legislative developments of beak trimming. Beak anatomy is reviewed and post-trimming physiological effects are considered, as they relate to pain. Methods of beak trimming and alternative solutions are presented.

Keywords: beak trimming, chickens, cannibalism, pain, welfare