Example enrichment study protocols

The example protocols below provide guidance on how to conduct an evaluation of environmental enrichment, using the approaches outlined in this web resource. General advice on adapting the protocols is available.

Consult the decision table to help you select the protocol that is most likely to meet your needs.

Description

Type

Useful documents

Protocol A: Use of an enrichment item (mouse mezzanine with shelter)

Preparation: create ethogram and playroom

Observation: daily flexibility; approx. 5 – 40 min per day

Behavioural observation

Protocol A: data collection sheet

Protocol A: looking at the data (page 5 of main protocol document)

Protocol A: example ethogram

General mouse ethogram (page 1 of general ethograms document)

Protocol B: Playrooms for rats

Preparation: create ethogram and playroom

Observation: daily flexibility; approx. 20 – 45 min per day

Behavioural observation

Protocol B: filling out the data collection sheet

Protocol B: option 1 data collection sheet

Protocol B: option 2 data collection sheet

Protocol B: option 3 data collection sheet

Protocol B: looking at the data (page 8 of main protocol document)

Protocol B: example ethogram

General rat ethogram (page 4 of general ethograms document)

Protocol C: Video recording zebrafish behaviour

Preparation: create ethogram, set up and test recording equipment

Observation: daily flexibility; approx. 20 – 45 min per day

Behavioural observation

Protocol C: data collection sheet

Protocol C: looking at the data (page 6 of main protocol document)

General zebrafish ethogram (page 6 of general ethograms document)

Protocol D: preference test

Preparation: modify cages

Observation: daily flexibility; approx. 5 – 10 min

Preference test

Protocol D: data collection sheet

Protocol D: looking at the data (page 6 of main protocol document)

Decision table

Which of these statements best describes your situation?

Options for evaluation

I am aiming to address a behaviour of concern (e.g. stereotypical overgrooming) through introduction or modification of enrichment.

Observe behaviour, focusing on frequency or duration of negative welfare indicators, consider adapting Protocols A, B or C.

 

For visible indicators of poor welfare, such as barbering, data can also be recorded during welfare checks.

 

Observe behaviour with and without the enrichment and make comparisons between these two.

I would generally like to improve welfare by introducing or modifying enrichment.

Observe behaviour, focusing on positive and negative welfare indicators. Consider adapting Protocols A, B or C.

 

Observe behaviour with and without the enrichment and make comparisons between these two.

I want to find out whether the animals use an enrichment item and how they use it.

Protocol A could be adapted.

 

I would like to find out what enrichment animals prefer when they are given a choice.

A preference test may be suitable, for which you could adapt Protocol D.

 

Preference for edible items within a group can be indicated by how much is eaten or chewed. You can use a scoring system or weigh items before introducing them to the cage and 24 hours later. These observations can be made for the group, so there is no need to singly house individuals.

I would like to find out how important it is to the animals to have access to enrichment.

A motivation or 'consumer demand' test may be suitable.

Examples of enrichment evaluations available online

Reference 

Evaluation type 

Study animals 

Enrichment evaluated 

Statistics 

[1] Windsor and Bates (2019) 

Nest scoring 

Safety observations 

Mice 

Four types of nesting material 

AVOVA 

[2] Schroeder et al. (2014) 

Preference test 

Zebrafish 

Different types of structural enrichment (sand, gravel and artificial plants) 

Kruskall-Wallis test; Wilcoxon test 

[3] Van Loo et al. (2004) 

Preference test 

Mice 

Nest boxes and nesting material 

Binomial test; t-test 

[4] Czezyk et al. (2020) 

Preference test 

Behavioural observation 

Zebrafish

Different types of structural enrichment (plastic plant, shelter, plastic lily pad) 

ANOVA 

[5] Li et al. (2019) 

Preference test 

Behavioural observation 

Piglets 

Music 

ANOVA 

[6] Tilly et al. (2010) 

Behavioural observation 

Motivation test 

Mice 

Smaller cage versus larger cage with more structural enrichment

Generalised linear model 

[7] Hanmer et al. (2010) 

Motivation test 

Rats 

Various toys and objects (e.g. polyester and fur covered blocks) 

ANOVA; t-test 

References

[1] Windsor Z, Bate ST (2019). Assessing the safety and suitability of nesting material for singly housed mice with surgically fitted head plates. Heliyon 5(7): e02097. doi:10.1016/j.heliyon.2019.e02097 

[2] Schroeder P, Jones S, Young IS et al. (2014). What do zebrafish want? Impact of social grouping, dominance and gender on preference for enrichment. Laboratory Animals 48(4): 328-337. doi:10.1177/0023677214538239 

[3] Van Loo PL, Blom HJ, Meijer MK et al. (2005). Assessment of the use of two commercially available environmental enrichments by laboratory mice by preference testing. Laboratory Animals 39(1): 58-67. doi:10.1258/0023677052886501 

[4] Czezyk A, Burn C, Russell C (2020). Does Providing Hiding Spaces for Zebrafish in Large Groups Reduce Aggressive Behaviour? Journal of Young Investigators 38(5). doi:10.22186/jyi.38.5.43-56 

[5] Li X, Zhao JN, Zhao P et al. (2019) Behavioural responses of piglets to different types of music. Animal 13(10): 2319-2326. doi:10.1017/S1751731119000260 

[6] Tilly SLC, Dallaire, J, Mason GJ (2010). Middle-aged mice with enrichment-resistant stereotypic behaviour show reduced motivation for enrichment. Animal Behaviour 80(3): 363-373. doi:10.1016/j.anbehav.2010.06.008 

[7] Hanmer LA, Riddell PM, Williams CM (2010). Using a runway paradigm to assess the relative strength of rats’ motivations for enrichment objects. Behavior research methods 42(2): 517-524. doi:10.3758/BRM.42.2.517