The Home Office released yesterday a second set of statistics of animals in research, following the publication of the number of scientific procedures using animals, released in July this year.

New figures published disclose the number of animals bred for scientific procedures that did not undergo any "regulated procedure". A procedure is defined as regulated if it has the potential to cause any pain, suffering, distress and lasting harm above a defined threshold.

The published figures show that in 2017, 1.81 million non-genetically altered animals of protected species (vertebrates and cephalopods) were bred for scientific procedures, but were killed or died without being used in regulated procedures.

The majority of these animals were mice (80%), 11% were rats and 7% were fish. These animals include those whose tissues have been used for in vitro experiments, animals bred for the purpose of experiments but not used because they are wild-type or have the wrong gender for a specific purpose, and sentinel animals in laboratories for disease monitoring.

Dr Mark Downs FRSB, chief executive of the RSB, commented: “The publication of these figures as a national statistic is welcome. It is a further step of open reporting for the bioscience sector involved with the use of animals in research.

“Furthermore, the shared European framework for reporting these figures will allow comparison of implementations of the EU Directive between jurisdictions, and support decision-making and harmonisation of standards”.

Earlier this year, in July, a set of statistics was published which reported the number of procedures using animals.

These figures counted the total number of regulated procedures, which does not necessarily correspond to the number of animals used. Furthermore, any licensed work with genetically altered animals (GAA) is classified as a regulated procedure, meaning procedures involving GAA were also included in the statistics published in July.

Professor Dominic Wells, chair of the RSB Animal Science Group, commented: “Advancement in animal science, such as development of organoids from pluripotent stem cells, both from laboratory animals and from human patients, or the faster generation of genetically altered animals using CRISPR/Cas9, are all impacting the type of animal breeding and tissues used in research, either by reducing the numbers of animals and procedures, refining the processes involved or replacing the use of animals altogether.

“Both animal scientists and the regulator are aware of the challenges involved in keeping colonies of animals and the unavoidable fact that not all animals bred will directly take part in an experimental study.

“It must be a goal to achieve a workable minimum number of animals bred and not used in procedures.

“The efforts by the scientific community to make the breeding processes more efficient are particularly welcome and must be further supported, such as correct archiving of GAA lines and colony management, and the sharing of resources across institutions, particularly gametes and embryos for GA lines and tissues harvested from adult animals.

“The figures published yesterday will help us track how new avenues of research and novel technologies will impact the field of breeding and will help to identify areas of potential efficiency, replacement, reduction and refinement.”

The return of animals for both sets of statistics has avoided double counting, with the Home Office reporting that animals of protected species used in research in 2017 amount to a total of 5.53 million.

This combines animals used for the first time in experimental procedures (33%, reported in July), animals used in the creation or breeding of GA lines (34%, reported in July), and non-GAA bred but not used further in procedures (33%, reported yesterday).

The duty to publish these additional statistics of animals bred for scientific procedures without being used in regulated procedures stems from a legal requirement in the Animals (Scientific Procedures) Act and the corresponding article 54 of the EU Directive 2010/63 on the protection of animals used for scientific purposes. This is the first year that the additional reporting is mandatory for all research establishments in EU member states. Each EU Member State from this year onwards will publish this data every five years.

In the UK, some research establishments already publish these additional figures online, and have done so for some years, due to the integral part these animals play either in scientific studies or in the processes involved in colony breeding. The processes involved in breeding animals for science are subject to stringent controls, regular review and the application of the 3Rs (reduction, refinement and replacement).

The Royal Society of Biology supports the use of animals in research when no alternatives are available and firmly maintains that excellence in science, and in animal welfare, go hand-in-hand.