Some chicken cages provide a "necessary defense" against bird flu, said the head of government veterinarians.
In a tweet, Nigel Gibbens said that the larger pens, which replaced the so-called battery cages in 2012, have welfare benefits and offer more space.
It occurs after 10 British veterans, who believe that the caged hens are unethical, said their "blatant endorsement" was "extremely disappointing."
They said that restricted space was "seriously detrimental to well-being".
Battery cages for chickens were banned in the EU in 2012. The ruling said that if the laying hens had to be kept in captivity they should be enriched, also known as colony cages.
The enriched cages provided more space for nesting, scratching and posing and the orientation of the Department of Environment, Food and Rural Affairs (Defra), is that each bird in an enriched cage must have at least 750 square centimeters of space.
The minimum for battery cages was 550 square centimeters.  Despite the ban on battery cages, several leading retailers have announced that they are moving towards the sale of free-range eggs.
But at the Eggs and Birds Industry Conference in October, Gibbens called this "regrettable movement" and "these cages" have a lot to them. "
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Criticizing it in a group In a letter to the Times, 10 veterinarians said that overcrowding and restricted space were" very detrimental to well-being ".  "Caged hens can not carry out specific species-specific behaviors."
The group dismissed their claims about protection against bird flu, saying there are other options to handle the threat and urged the head of veterinarians to take a "more progressive position."
Mr. Gibbens then defended his view on Twitter and said: "Risks of disease free range that is really bad for the welfare star. "
Colony cages offer welfare benefits and more space than the battery cages they replaced. Housing is a necessary defense against bird flu in times of high risk. Compelling free range runs the risk of a disease that is really bad for well-being. https://t.co/9H2tvUsnO8
– NigelGibbensChiefVet (@ChiefVetUK) December 2, 2017
A spokeswoman for Defra said: "The cages enriched offer less exposure to the threat of bird flu during an outbreak than free-field systems, and provide more space on the floor and more height than battery cages. "