The animals cannot display their natural patterns of behaviour, such as scratching, nest building, flying, dust bathing and scratching for food. Hens in battery cages also lay approximately 300 eggs a year, whereas wild hens traditionally laid less than 20 a year. This forced over-production of eggs severely strains the animals' bodies, leading to osteoporosis and low calcium levels.
The distressed and desperate hens can peck each other and behave aggressively. To prevent this, some egg producers chop off part of the hens' beaks, a painful and unnecessary practice.
READ MORE: Craddock Farms denied appeal to build egg-producing farm
The hens' lives are short. Their stressed bodies cannot keep laying 300 eggs a year so, after a year or two when their egg production rates drop, the hens are of no further use to the industry and are sent for slaughter.
Male chicks are of no use for egg production, so they are killed within a few days of birth. The male birds are slaughtered either by being sliced alive in a high-speed machine - a process known as maceration - or by being gassed with carbon dioxide.
Germany kills 45 million male chicks each year, either by maceration or by gassing. However, an outcry over maceration has led to scientists developing an alternative. New technology will be used to determine the sex of each fertilised egg before chicks develop, and Germany expects to end maceration by 2017.
In New Zealand, public opposition to the cruelty of battery cages led the Government to ban them, but the gradual phase-out is extremely slow and will not take full effect until 2022.
And instead of banning hen cages altogether, the Government decided that battery cages would be replaced by "colony" or "enriched" cages. This is nonsense. Colony cages give each hen extra space equivalent only to the size of a credit card. This means that egg producers will be spending millions of dollars on changing to a system that provides very minimal animal welfare improvements for hens.
It is inevitable that hen cages will in future be banned altogether. Why not do this now and place New Zealand among the leaders in animal welfare internationally, rather than have us lagging behind ?
Last Monday, (21 March 2016), the Environment Court refused an appeal by Craddock Farms against a decision declining it a resource consent for a 310,000 caged hen farm at Patumahoe. The proposal was for 10 sheds, with up to 31,000 hens in each building.
It is impossible for hens to have any quality of life when they live in such intensive farms. The fact that such a farm was even proposed shows how backward our thinking still is. We should be moving completely away from such animal factories and housing all hens on free range farms.
The Government's lack of action on hen welfare means that supermarkets and other retail outlets which sell eggs or use them in other products, have also been slow to act. For example, one of New Zealand's two large supermarket chains - Countdown - is owned by Woolworths Australia. Woolworths Australia has pledged to stop selling cage eggs by 2018. But, in New Zealand, Countdown is refusing to make a similar commitment.
Supermarkets have massive power to influence animal welfare, as they are such huge markets for suppliers. Countdown and Foodstuffs would improve millions of hens' lives if they decided to stock only free-range eggs.
All they have to do is to follow the example of McDonald's which has pledged to stop using cage eggs in its 164 New Zealand outlets by the end of 2016. Why can't Countdown and Foodstuffs do the same? And, if Countdown can do it in Australia, why can't it stop using cage eggs in New Zealand?
And it is not only hens' lives which do not live up to the Easter advertising hype. The Easter bunny is seen on television merrily hopping around meadows carrying a straw basket.
But what happens in reality in New Zealand is very different. The annual Cromwell Easter Bunny Hunt results in the slaughter of thousands of rabbits because humans deem rabbits to be "pests."
The painful disease myxomatosis was deliberately introduced to kill rabbits in the early 1950s, and subsequently Rabbit Calicivirus Disease was illegally released in Otago in 1997. Poisoning, gassing and the ripping up of burrows have also been used, with many rabbits dying in agony after being poisoned with 1080.
At present, farmers are seeking approval for the release of a Korean strain of RCD - RHDV1-K5 - with plans for it to be introduced in 2017.
And New Zealand continues to use rabbits and other animals for painful and often deadly testing, despite the many alternatives available. 310,287 animals were used in testing in 2014, with 106,739 dying in the process. Those figures included 1445 rabbits.
As New Zealanders begin the Easter break, it would be good to think that by next Easter we would have taken significant steps to improve our treatment, not only of hens and rabbits, but of other animals as well.
Catriona MacLennan is a barrister and journalist.
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