Welfare Archives - The Sciku Project

May 20, 2021May 20, 2021

Xenopus Enrichment

Smooth frogs and fake plants
embracing in the water.
Happiness is here.

The African Clawed Frog, Xenopus laevis, is a common laboratory model species of amphibian, used in research primarily for their embryos and eggs. Yet despite their popularity little attention has been given to the housing and husbandry – what is the best way to keep the African Clawed Frog?

Recently, however, things have begun to change as more attention is being given to the welfare of ‘lower’ vertebrates and invertebrates. Indeed, in 2016 we published research demonstrating that a darker tank background resulted in lower levels of corticosterone (a stress hormone), lower instances of stereotypical behaviour and less change in body mass (Holmes et al, 2016). The results suggest that darker backgrounds are better for African Clawed frog welfare in captivity (check out the sciku ‘Clawed frogs indicate‘ for more information about the study and the likely reasons behind the preference).

Now in 2021 new research has been published by Ramos and Ortiz-Díez that examines X. laevis preferences for types of physical enrichment within their tanks. The researchers provided tanks of frogs with artificial plants and opaque PVC tunnels and checked on the frogs three times a day for 6 weeks to see where in the tanks they were spending their time – with the plants, tunnels or in the open areas of the tanks. The results indicate that the frogs preferred the plants 40% more than the tunnels, although both were preferred over the areas of open space in the tank.

As research into the welfare of amphibians gains momentum it’s good to see more work focussing on this common laboratory animal and how it’s kept in captivity. Particularly warming is that in the experimental methods the researchers specifically state that tanks with dark sides and bases were used to reduce visual stress, referencing our earlier work.

Original research: https://doi.org/10.1177%2F00236772211011290

A note about the sciku: The phrase ‘smooth frogs’ that starts the poem is a reference to the meaning of the name laevis – smooth (the word Xenopus means ‘strange foot’).

Interested in African clawed frogs? Check out these other Xenopus sciku: ‘Clawed frogs indicate‘, ‘Have frog, will travel‘, ‘Fungal culprit‘ and ‘Reservoir or predator‘.

March 25, 2021March 25, 2021

The Masterplan by Dr Lisa Holmes

Zoo science prevails
Conservation cannot wait
“Prevent extinction”
By Lisa Holmes

Celebrating its 90th year, Chester Zoo is one of the world’s leading zoo’s, housing more than 500 species and dedicated to their mission of “Preventing extinction”.

This week marks the release of their new 10 year Conservation Masterplan; a bold vision with the aim to tackle the global extinction crisis using six key targets:

Preserve options for future conservation for an additional 150 species through conservation breeding and propagation.
Halt or reverse the decline of 200 highly threatened populations of plants and animal species in the wild.
Improve landscapes for wildlife totalling 250,000 hectares.
Train 5,000 conservationists to deliver positive change for wildlife.
Empower 10 million people to live more sustainably.
Influence change in five major policy areas for wildlife.

Chester Zoo has an integrated approach to conservation using the skills and expertise of their staff, conservation partners, students, academics and supporters.

Dr Lisa Holmes is the Lead Conservation Scientist for Behaviour and Welfare at the zoo. She works closely with the animal curators and teams to provide an evidence-base for management decisions. With her team of staff and students, she conducts research to monitor the wellbeing of all species and is developing tailored welfare assessments for use within the zoo. She is also Vice-Chair of the Animal Welfare Working Group for the European Association of Zoos and Aquaria (EAZA).

Check out Lisa’s previous sciku ‘A Zoo Without Bars’.

You can read Chester Zoo’s Conservation Masterplan by clicking on the image below:

April 17, 2018May 20, 2021

Have frog, will travel

Have frog, will travel,

yet what impact on welfare?

Best to avoid moss.

Transporting animals for research, agricultural, conservation or leisure reasons can involve a range of potential stressors. It’s therefore important to be aware of the impact of transportation on animals so as to minimise any negative effects.

African clawed frogs are a common laboratory animal, used for a range of developmental studies. Holmes et al (2018) investigated the impact of transportation between research facilities. They found that transportation and re-housing had a negative impact across a short- and longer-term, with corticosterone (a ‘stress hormone’) remaining high for 1 week and body mass remaining low for 5 weeks after transportation. Investigating further the researchers found evidence that being transported in moss might be the least preferable transport medium, with water or sponge appearing to be more suitable.

Original research: https://doi.org/10.1016/j.ygcen.2018.03.015

Interested in African clawed frogs? Check out these other Xenopus sciku: ‘Clawed frogs indicate‘, ‘Xenopus enrichment‘, ‘Fungal culprit‘ and ‘Reservoir or predator‘.

April 3, 2018April 27, 2018

How you handle mice

affects response to rewards.

Science improves too!

There is an increasing body of research to suggest that handling laboratory mice by the tail is both bad for their welfare and the science that the mice are studied for. Tail handling has negative impacts on mouse behaviour and physiology, with tunnel and cupping handling techniques resulting in behavioural improvements across various common behavioural bioassays, including the elevated plus maze, the open field test and the habituation-dishabituation paradigm.

Now new research suggests that handling is also important for reward-based behavioural assays. A study by Clarkson et al (2018) examined mouse response to sucrose solution (a common reward). They found that tail handled mice showed a reduced response to the sucrose than the tunnel handling method, a finding indicative of the tail handled mice having a ‘decreased responsiveness to reward and potentially a more depressive-like state’.

Across eight years and five research papers, from three distinct research groups in two countries, the field of laboratory mouse research has been irrevocably changed. Combined, the research suggests that tail handling results in poor animal welfare and potentially erroneous scientific results. The National Centre for the Replacement, Refinement & Reduction of Animals in Research now has extensive information on mouse handling techniques, example videos, tips and testimonials for researchers and animal carers to find out more about changing their current mouse handling methods to the tunnel or cupping techniques.

Original research: http://dx.doi.org/10.1038/s41598-018-20716-3

April 3, 2018April 30, 2018

Tunnels and cupping

beat tail handling mice for

behavioural tests.

Laboratory mouse handling method can affect mouse behaviour and physiology, and new research suggests that it can also impinge on mouse performance in behavioural tests. Research by Gouveia and Hurst (2017) found that tail handled mice performed poorly in a habituation-dishabituation paradigm test in comparison to cupped or tunnel handled mice. The tail handled mice ‘showed little willingness to explore and investigate test stimuli’ and even prior familiarisation with the test arena didn’t improve their performance much.

Combined with the previous research findings on mouse handling this research continues to expand on the long-reaching impacts of mouse handling technique on both mouse welfare and scientific experimental rigour and asks the question – just how valid are behavioural tests using laboratory mice that have been tail handled? Yet the story of mouse handling is not yet done, click here for the final instalment of this tale/tail!

Original research: http://dx.doi.org/10.1038/srep44999

April 3, 2018April 30, 2018

Cup handled mice

Cup handled mice show

improved glucose tolerance

and less anxiousness.

When performing scientific research with animals, it’s important to ensure that the procedures used do not themselves impact upon the results obtained. Laboratory mouse handling method has already been shown to impact upon mouse anxiety in common behavioural tests. However it seems that handling can have physiological impacts too.

Ghosal et al (2015) compared the behavioural and physiological responses of laboratory mice to either tail handling or cupped handling techniques. Cupped handled mice showed fewer anxious behaviours in a common behavioural test, reduced blood glucose levels and a lower stress-induced plasma corticosterone concentration in response to an overnight fast compared to tail handled mice. The researchers also found that obese laboratory mice handled using the cupped method demonstrated improved glucose tolerance.

Replication and repeatability are crucial components of science and this paper is a perfect demonstration of this – the researchers are from different research laboratories and in a different country to the mouse handling work that preceded it. In this way not only does it build on what came before, it also strengthens those earlier findings. Yet the mouse handling story is not finished yet, click here for the next chapter of this tale/tail!

Original research: https://doi.org/10.1016/j.physbeh.2015.06.021

April 3, 2018April 30, 2018

Reducing mouse anxiety

Further reducing

mouse anxiety using

familiar tunnels.

Building on the finding that handling laboratory mice using a tunnel resulted in lower anxiety than picking them up by the tail, Gouveia and Hurst (2013) next investigated whether familiarity with the tunnel might be an important factor. Once again they found that tunnel handling resulted in lower anxiety than tail handling during an elevated plus maze (a common behavioural test for laboratory mice).

This time they found differences between mouse strains, with C57BL/6 mice being most interactive towards tunnels from their home cage and ICR mice showing no difference in interaction between familiar home cage tunnels and novel tunnels previously used for handling mice from other cages. The researchers suggest that ‘as home cage tunnels can further improve response to handling in some mice, we recommend that mice are handled with a tunnel provided in their home cage where possible as a simple, practical method to minimise handling stress’. The tunnel would also act as a form of environmental enrichment for the home cage.

In science it’s rare to tell a complete story through the findings of two research papers, click here for the next chapter of this tale/tail!

Original research: https://doi.org/10.1371/journal.pone.0066401

April 3, 2018April 30, 2018

The little changes

can make a big difference:

Handle mice with care.

Traditionally laboratory mice are handled by picking them up by the tail, yet increasing evidence suggests that this is bad, both for the mice themselves and the quality of the science they are being used for. The evidence for this started building from Hurst and West’s 2010 study which demonstrated that handling by the tail resulted in increased aversion and anxiety.

The researchers proposed two alternative methods for handling laboratory mice: holding the mice cupped in the hands or using tunnels that the mice can crawl into and be transported by carrying the tunnels. These novel methods of handling led to the mice approaching the handler voluntarily, being more accepting of physical restraint and showing lower levels of anxiety.

In science it’s rare to tell a complete story through the findings of a single research paper, click here for the next chapter of this tale/tail!

Original research: http://dx.doi.org/10.1038/nmeth.1500

March 2, 2018March 2, 2018

When I talk about running

What I remember

when I talk about running:

Stress fading away.

Proponents of exercise have long sung its praises as a way of staying physically healthy, but there is increasing evidence that it has mental health benefits as well. Miller et al (2018) found that exercise (and specifically running) helped reduce the impact of chronic stress on the brain.

The scientists compared stressed and unstressed mice that either had access to a running wheel or not. Mice that were able to exercise mitigated some of the negative impacts of stress, whilst mice that were unable to exercise showed a reduction in the long-term potential of their hippocampal function (the part of the brain responsible for learning and memory).

In honour of World Book Day the poem references Haruki Murakami’s excellent meditation on running and life ‘What I Talk About When I Talk About Running’, which itself was a play on Raymond Carver’s ‘What We Talk About When We Talk About Love’.

Original research: https://doi.org/10.1016/j.nlm.2018.01.008

January 23, 2018January 23, 2018

Beak trimming distaste

Beak trimming distaste,

yet long beaks lead to poor health.

Best of a bad bunch?

Sometimes it’s better to cause harm for the right reasons rather than allowing worse harm to occur. Egg-laying barn hens typically have their beaks trimmed to reduce pecking damage but this practice results in pain and sensory loss for the birds. As a result the practice of beak trimming is being debated worldwide and some countries have already banned it based on welfare concerns.

Riber and Hinrichsen (2017) compared the welfare of trimmed and non-trimmed flocks of hens across 10 separate farms and across 62 weeks. They found that beak trimming actually resulted in higher conditions of hen plumage, skin and keel bones, as well as decreased mortality. Whilst beak trimming seems distasteful, this evidence suggests that it may be the best option after all.

Original research: https://doi.org/10.3389/fvets.2017.00222

January 19, 2018January 19, 2018

Increase carpet tog

Cold stress avoided

in laboratory mice –

increase carpet tog.

Temperature is an important element of animal care and it’s crucial to ensure that captive animals don’t overheat or suffer cold stress. Laboratory mice are often housed with a floor substrate of wood chips which may be useful in reducing cold stress.

Freymann et al (2017) found that the depth of this floor material influenced mouse physiology. Specifically a deeper wood chip layer resulted in mice with reduced adrenal, liver, kidney and heart weights and an increased tail length. These traits have previously been observed in mice housed under warmer conditions suggesting that the deeper substrate material is acting as an insulator and could be used to reduce cold stress in this captive species.

Original research: https://doi.org/10.1177/0023677217694400

December 18, 2017December 18, 2017

Exploiting blind spots

Tropical clawed frogs –

what you can’t see can’t hurt you.

Exploiting blind spots.

Providing sufficient shelter for animals in captivity is frequently an important method to improve welfare, however cover may limit the ability to observe animals for health checks. Western clawed frogs (or tropical clawed frogs) are a common model organism, kept in high numbers in laboratories around the world, but there is comparatively little empirical evidence for how best to adequately house this species in captivity.

Cooke (2017) found that a black overhead cover was the optimal method of providing refuge for this species. In a second experiment exploiting the frog’s inability to see certain wavelengths the black cover was swapped for a red translucent cover which was found to be just as effective.

Red translucent covers could therefore be an effective method of providing refuge for the animals whilst simultaneously allowing carers to observe and conduct health checks.

Original research: https://doi.org/10.1177/0023677217737798

November 15, 2017March 25, 2021

A zoo without bars by Dr Lisa Holmes

A zoo without bars –

Building thoughtful habitats

for all to explore.

Chester Zoo (www.chesterzoo.org) is a registered conservation and education charity that supports projects around the world and closer to home in Cheshire. Welcoming 1.9 million visitors a year, it is the most visited zoo in the UK; home to over 15,000 animals and more than 500 different species, many of which are endangered in the wild.

Chester Zoo has continued with the ‘always building’ philosophy of our founder, George Mottershead, who created the UK’s first zoo without bars and focused on animal wellbeing and conservation. In 2015 Chester Zoo opened Islands which was the largest zoological development in the UK to date. The Islands expedition is an immersive experience, taking visitors through six South East Asian islands to discover the incredible wildlife native to those areas and highlight the conservation issues that the zoo staff are working hard to address.

Modern day zoo research encompasses many aspects of biological and social sciences with the overall aim to address challenges faced in the natural world. Chester Zoo not only supports conservation research both in- and ex-situ but leads on important projects both in the UK and across the globe to improve the management of animals and plants, influence sustainability of wild populations and inspire others to Act for Wildlife.

Lisa Holmes is the Behaviour and Welfare Scientist within the Applied Science team at Chester Zoo. Her role involves working closely with the animal curators and keepers to provide evidence-based recommendations to enhance animal wellbeing and help to inform enclosure design. Lisa supervises postgraduate and sandwich placement students who help to gather key data for a wide range of species. Lisa’s research team are currently working on a long-term project assessing the response of species which have moved into the new Islands habitats.

Check out Lisa’s latest sciku ‘The Masterplan’ here.

September 22, 2017December 11, 2017

Do creepy-crawlies suffer?

Do creepy-crawlies

suffer as live food? Is this

a welfare concern?

Invertebrates are often used as live food for other animals in captivity (for example geckos are often fed live crickets). Increasingly there are suggestions that some invertebrate species may be able to experience a sensation of pain and may have higher cognitive functions such as emotions and learning. As a result, should we be considering the ethical and welfare issues associated with using invertebrates as live prey?

Keller (2017) has published a review of the latest research into invertebrates and how institutes using live prey might consider and act on any welfare implications. Since there is mounting evidence that some invertebrate species can suffer, perhaps it would be best to stop all live prey feeding? But this response has its own problems: live prey feeding provides enrichment to captive species and many captive species will not feed if the food item is dead.

September 4, 2017September 4, 2017

Is ‘P’ suitable?

Refine and reduce

for animal welfare, but

is ‘P’ suitable?

Statistics and animal welfare might seem like unlikely bedfellows but a greater understanding of statistics may actually improve animal welfare. The 3Rs – Replacement, Reduction and Refinement – are critical for the ethical use of animals in experiments, but sometimes the animal species concerned cannot be replaced with a more ethical substitute. Refining procedures and reducing the numbers of animals tested should therefore be a fundamental consideration of any animal experiment.

Determining an appropriate sample size is often done using power analyses based around the P-value, but increasingly there is concern about the validity of this statistical term as a means of accepting or rejecting the experimental hypothesis. Instead, effect sizes and confidence intervals could be used to determine an experiment’s outcome and, in turn, minimum suitable sample size could be calculated using effect size precision. In this way statistics can be used to improve animal welfare by reducing the numbers of animals used. Sneddon et al, 2017.

July 21, 2017May 20, 2021

Clawed frogs indicate

by action and reaction

a choice between shades.

Ensuring the welfare of animals used for research is vital both from an ethical stand point and for the quality of the research produced – animals in poor condition do not produce accurate or reliable results. The African clawed frog is a common research species found in laboratories around the world but little work has investigated how to optimally house it in captivity.

Holmes et al (2016) found that a black tank background produced lower levels of ‘stress’ hormone (corticosterone), lower amounts of stereotypical behaviour and a smaller loss in body mass than a white tank background.

As African clawed frogs are naturally dark green/brown in colour and use camouflage to avoid predation, a light background might be more stressful for the frogs as they may appear more exposed. Providing dark tank backgrounds could therefore be an easy method for improving the welfare of thousands of African clawed frogs housed in captivity around the world.

Interested in African clawed frogs? Check out these other Xenopus sciku: ‘Fungal culprit‘, ‘Have frog, will travel‘, ‘Xenopus enrichment‘ and ‘Reservoir or predator‘.