New Cage Design for Laying Hens

New Cage Design for Laying Hens

New Cage Design for Laying Hens U. A. LUESCHER,1 J. F. HURNIK,' and J. POS 2 Department of Animal and Poultry Science and School of Engineering, Unive...

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New Cage Design for Laying Hens U. A. LUESCHER,1 J. F. HURNIK,' and J. POS 2 Department of Animal and Poultry Science and School of Engineering, University Guelph, Ontario, Canada NIG 2W1

ofGuelph,

(Received for publication August 26, 1981) ABSTRACT Battery cages for laying hens are being increasingly criticized as providing an inadequate environment for the welfare of birds. A prototype cage design, which should come closer to meeting the ethological needs of chickens, presently is being developed at the University of Guelph. Its basic principle focuses on varying the internal cage environment in time rather than in space according to the circadian behavioral rhythms of the birds. (Key words: laying hens, cage design, behavior, animal welfare)

INTRODUCTION

Battery cages for laying hens are widely used in the commercial production of chicken eggs. The reason for their widespread acceptance is high production efficiency due to high bird density, better feed conversion, lower labor costs, and easier visual inspection of birds. However, battery cages have been heavily criticized as being inadequate for animal welfare. There exists, therefore, good reason to develop an alternative cage system which accommodates the behavioral needs of the birds without impairing the economic interests of the producer and the affordability of the poultry products for consumers. Attempts to do this have been made, including the development of colony cages and "Get Away" cages (Bareham, 1976; Brantas, 1978). The colony cage actually yields no improvement for the birds and even increases social interference. The "Get Away" cage provides a more complex environment, allowing the hens to manifest more of their natural behavior repertoire. However, it requires more space and a pronounced decrease in stocking density. Most behaviors follow a distinct circadian rhythm and are influenced by social facilitation. Consequently, there is competition for certain features of the cage at certain times of the day, while at the same time other parts are not in use. Since this results in poor utilization of space, it may be more efficient to alter the

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Department of Animal and Poultry Science. School of Engineering.

environment in time rather than in space, allowing all the hens to conduct various behavioral activities during the period of time when such behavior is generally performed in natural circumstances. This might be achieved by equipping a battery cage with devices which could be presented to the hens at the appropriate time of the day (Hurnik, 1979). Having the approximate dimensions of a commercial battery cage, it could sustain densities of birds similar to the ones found in commercial operations. Such a cage is presently under development at the University of Guelph. As a first step, the use of a moveable roost is being tested (Fig. 1).

EXPERIMENTAL PROCEDURE

Shallow cages (45 cm wide, 32.5 cm deep, and 37.5 cm high) are equipped with a wooden perch extending from one side of the cage to the other, parallel to the feed trough at a distance of 12.5 cm from it. The perch is 3.5 cm wide and kept level with the cage floor when not in operation, allowing eggs to roll through the cage. Controlled by a timer, it can be raised approximately 4 cm, providing the hens with an opportunity to roost comfortably. The slot in the cage floor for the roost is sufficiently wide so that toes are not caught between the roost and the wire floor. The movement of the roost is slow (taking 5 sec) to provide enough time for the birds to leave the descending roost without undue disturbance. A unit of 108 cages with roosts and an iden-

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1982 Poultry Science 61:606-607

RESEARCH NOTE 32.5 cm

607 DISCUSSION

FIG. 1. Schematic illustration of the cage showing the roost in raised and lowered position.

tical unit w i t h o u t roosts are being used for the

investigation. The roosts are raised 15 min before the lights go out and lowered 15 min after the lights come on. A stocking density effect is also being studied, and 1 to 4 hens have been assigned randomly to each cage.

REFERENCES Bareham, J. R., 1976. A comparison of the behaviour and production of laying hens in experimental and conventional battery cages. Appl. Anim. Ethol. 2:291-303. Brantas, G. C , 1978. Ethologische Betrachtungen an Legehennen in Get-away-Kaefigen. Arch. Gefluegelkd. 42-129-132. Hurnik, J. F., 1979. Behaviour and cage design. Pages 18—24 in Poultry Industry School. University of Guelph, Ontario.

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Preliminary observations reveal that the best use of the roost is made at a stocking density of two hens per cage (up to 90% of their resting time at night is spent sitting on the roost). Up to the third month of production, no significant differences have been found in number of eggs laid and egg quality traits. Similarly, the scores for feathering and excitability do not differ so far between experimental and control groups. A further step planned in the development of the cage is to shelter the cage during the peak of oviposition so that the whole cage is changed into a laying nest during that time. In addition, feed delivery will be synchronized with the time of maximal feed intake.