UNIVERSITY BOSSES tested on almost 7,000 animals last year, an investigation by York Vision can reveal.
Among the 6,814 experiments between 1 January 2013 and 1 January 2014, most, at 6,353, were using mice.
Only 328 rats and 133 zebrafish were tested on, according to a Freedom of Information request.
Animal rights groups say they are opposed to testing.
They originally planned to protest at the university in 2012 after more than 10,000 were experimented on between January 2011 and January 2012.
But last week bosses said they were keen to continue to reduce the number of animals that York tested on.
Of the experiments used, all were used for medical research including on cell development, breast cancer research and autoimmune diabetes.
The highest number of experiments was on GM mouse breeding, which used 2,674 mice.
The lowest was gastrointestinal inflammation, using 4 rats.
A university spokesman said: “The University has an open and transparent approach to animal testing. We are committed to the principle of the 3 Rs – reduction, refinement and replacement.
“We avoid the use of animals except where it is absolutely necessary for the advancement of medical science.”