Enhancing Animal Welfare Through Environmental Enrichment: A Cross-Industry Survey Insight

1. DART Study Enrichment-what are we doing? Results of a cross-industry survey

2. What is EE? • Environmental enrichment (EE) is any modification in the environment of the captive animals that seeks to enhance its physical and psychological well-being by providing stimuli meeting the animals’ species-specific needs

3. Types of EE • Social enrichment, which can involve either direct or indirect (visual, olfactory, auditory) contact with conspecifics(other individuals of the same species) or humans. • Occupational enrichment, which encompasses both psychological enrichment (e.g., devices that provide animals with control or challenges) and enrichment that encourages exercise. • Physical enrichment, which can involve altering the size or complexity of the animal’s enclosure or adding accessories to the enclosure such as objects, substrate, or permanent structures (e.g., nestboxes). • Sensory enrichment, or stimuli that are visual (e.g., television), auditory (music, vocalizations), or in other modalities (e.g., olfactory, tactile, taste). • Nutritional enrichment, which can involve either presenting varied or novel food types or changing the method of food delivery.

4. Why use EE? • Reduce the incidence or severity of undesirable or abnormal behaviors • Barbering and related alopecia • Self-mutilation • Repetitive/stereotypic behaviors • Depressed behaviors • “Crazy” bunnies • Help with tooth over-growth • Regulatory body directives • AAALAC, etc.

5. Where are we now? • Survey sent to 13 companies with in- house DART programs in the US and Europe addressing: • EE practices for rats & rabbits • Uses of edible vs. non-edible enrichment • 11 respondents, with responses from CROs, pharmaceutical, and chemical companies with in-house animal facilities.

6. Rabbits

7. Rabbits: Non-edible a – One respondent only plays music for Dutch-Belted rabbits

8. Rabbit Music Why? When?

9. Rabbit Music • What? (≥1 response/respondee) • Pop 1 • Rock 2 • New Age 1 • Radio 3 • Country 1 • Classical 3 • Easy Listening 1 • Anything with no loud bass or startling sounds 1 CRP (rabbit vendor) uses both music and talk (spoken word) radio. 

10. Rabbit Manipulatives • Hanging stainless-steel items: • Washer rings • Chains • Bells • Mirrors • Rattles • Bowls • Triangles • Rolling toys: Jingle ball (contains SS washer noise makers), SS ball, Taz balls, PVC pipe • Chew toys: Aspen wood block, Flexi keys, Nylabones, Cyclone chew, Dumbbell, Cardboard trays/tunnels

11. BMS rabbit caging

12. AZ rabbit caging

13. Rabbit Exercise • Methodology rabbits group-housed in floor pens • Study animals rotated into a exercise pens (AZ example below)

14. Rabbits: Edible Enrichment a – One respondent gives food enrichment to pre-study or non-study rabbits only; all others give enrichment to study animals (routine and/or inappentence)

15. Routine edible enrichment • What? (≥1 response/respondee) • Kale 1 • Timothy hay cubes (1× daily-weekly) 4 • Rabbit stixa (Bio-Serv®) 2 • Alfalfa cubes 1 • Fruit 1 • Veggies 1 • Loose hay 1 • Bunny blocks (Bio-Serv®) 1 • Cereal 1 a – Certified, high-fiber pineapple-flavored, maintenance diet, supplement, or enrichment treat

16. Edible enrichment for inappetence • What? (≥1 response/respondee) • Loose hay • Fresh produce (carrots, apples) • Yogurt • Wheat cereal • Timothy hay cubes (1× daily-weekly) • Gel diet • Bunny blocks (Bio-Serv®) • Dry diet moistened 50:50 (w/w) with warm water • Fruity gems (Bio-Serv®) • Organic granola

17. Criteria for inappetence • Veterinary recommendation •  Food consumption • < 30 g/day • < 50 g/day • < 100 g/day •  Fecal output • Considerations: age, sex, arrival date, behavior • Based on individual animal condition, not group mean patterns

18. Edible enrichment considerations • Drug-food interactions • Grapefruit - Cyp 3A4 inhibitor • Brussels sprouts, broccoli, cabbage, kale – Cyp 1A2 enzyme inducers • Anti-coagulants & dietary Vitamin K • Kale/spinach

19. Rats

20. Rats: Non-edible a – Was not specifically queried, but one respondent uses music for all animals, including rats.

21. Rat Manipulatives • Hanging stainless-steel items: • Nuts and bolts • Jingle Tags • “Mouse relaxer” • Hiding Devices:huts, tunnels, houses • Chew toys: Nylapucks, gummy bones, nylabones, wood blocks, cyclone chews, chewsticks • Nesting/bedding materials: Aspen wood shavings, Crink’lNest, nestlets, alpha twist, sizzlenest • Other: Non-woven gauze

22. BMS: Custom-made with SS nuts instead of nylon spacers. They love them!!

23. BMS: Tunnels are always a rat favorite…we have seen entire litters cram themselves inside one.

24. Rats: Edible Enrichment a 2 respondents routine for non-study rats (methodology or training rats); 1 used for behaviorial reward in specific instances

25. Types of edible enrichment (rat) • Routine (≥1 response/respondee) • Cereal 1 • Yogurt drops 1 • Bacon yummies 1 • Supreme Mini-treats 1 • BLT 1 • Inappetencea(≥1 response/respondee) • Fruity gems • Gel diet • Portion of bunny block aCriteria: marked decrease in food consumption, body-weight loss, few or no feces, certain behavioral changes

26. Summary • Use of enrichment is pervasive in DART studies. • Rabbits: Music, manipulatives, and edible forms are all routinely used • Rats: Manipulatives and nesting materials are common, with only minimal uses of edible enrichment • Consumption of edible enrichment is not routinely measured in nearly all instances

27. Thank you to all survey respondents!Any Questions?