Maintenance and breeding of laboratory animals MCQs With Answer

Maintenance and breeding of laboratory animals MCQs With Answer

This quiz series is designed for M.Pharm students studying Pharmacological and Toxicological Screening Methods-I. It focuses on practical and theoretical aspects of maintaining and breeding laboratory animals used in preclinical research. Topics covered include housing standards, environmental control, nutrition, breeding systems, genetics, health monitoring, identification, quarantine, and ethical/regulatory requirements. Questions are crafted to reinforce decision making in colony management, ensure reproducible experimental outcomes, and minimize variables related to animal husbandry. Use these MCQs to test knowledge required for designing, conducting, and interpreting pharmacological and toxicological studies involving laboratory animals.

Q1. What is the most appropriate ambient temperature range for housing adult laboratory mice to minimize thermal stress?

• 10–15°C
• 18–26°C
• 28–32°C
• 5–12°C

Correct Answer: 18–26°C

Q2. Which practice is best for preventing introduction of infectious agents into a rodent colony?

• Frequent bedding changes
• Quarantine and health screening of new arrivals
• Increasing cage density
• Sharing water bottles between cages

Correct Answer: Quarantine and health screening of new arrivals

Q3. Which mouse breeding system is most suitable to maintain an inbred strain with minimal genetic variation?

• Rotational outbreeding
• Brother–sister mating for >20 generations
• Random mating within a large colony
• Harem mating with multiple males

Correct Answer: Brother–sister mating for >20 generations

Q4. What is the primary purpose of sentinel animals in a rodent facility?

• Increase colony breeding efficiency
• Detect pathogens present in the facility
• Serve as breeding stock for experiments
• Provide enrichment for other animals

Correct Answer: Detect pathogens present in the facility

Q5. Which of the following is the recommended minimum number of cage changes per week for standard laboratory rat cages under non-SPF conditions?

• Once every two weeks
• Daily
• Two to three times per week
• Once per month

Correct Answer: Two to three times per week

Q6. For timed-pregnancy studies in mice, which sign is most commonly used to confirm copulation?

• Weight loss of the female
• Presence of a copulatory plug
• Increased activity at night
• Change in fur coloration

Correct Answer: Presence of a copulatory plug

Q7. What does “SPF” stand for in laboratory animal colony management?

• Standard Pathogen Free
• Specific Pathogen Free
• Specialized Protected Facility
• Sterile Pathogen Free

Correct Answer: Specific Pathogen Free

Q8. Which factor has the greatest influence on reproducibility of pharmacological studies using rodents?

• Color of cage bedding
• Consistency of husbandry and environmental conditions
• Frequency of handling by technicians
• Use of different food brands every week

Correct Answer: Consistency of husbandry and environmental conditions

Q9. What is the typical gestation period of an albino Wistar rat?

• 21–23 days
• 28–30 days
• 16–18 days
• 32–35 days

Correct Answer: 21–23 days

Q10. Which identification method is considered permanent and suitable for mice used across multiple experiments?

• Temporary ink marking
• Tail marking with dye
• Ear punch or ear notch
• Placing colored cage cards

Correct Answer: Ear punch or ear notch

Q11. In a breeding colony, what does a high pre-weaning mortality usually indicate?

• Excessive enrichment items
• Problems with maternal care, disease, or environmental stress
• Optimal breeding performance
• Too low a breeding age for males

Correct Answer: Problems with maternal care, disease, or environmental stress

Q12. Which dietary component is most critical to control for reproducible toxicology studies?

• Color additives in the feed
• Consistent nutrient composition and phytoestrogen content
• Packaging material of the feed
• Shape of the feed pellets

Correct Answer: Consistent nutrient composition and phytoestrogen content

Q13. What is the recommended minimum light:dark cycle for nocturnal rodents to maintain circadian rhythm?

• 24 hours light
• 18 hours light : 6 hours dark
• 12 hours light : 12 hours dark
• 6 hours light : 18 hours dark

Correct Answer: 12 hours light : 12 hours dark

Q14. Which practice reduces genetic drift in a large outbred stock used for toxicology screening?

• Rotating breeders randomly without records
• Maintaining a defined colony pedigree and controlled breeder selection
• Replacing breeders monthly with wild-caught animals
• Mixing litters frequently to equalize sizes

Correct Answer: Maintaining a defined colony pedigree and controlled breeder selection

Q15. For colony health monitoring, which sample type is typically tested to screen for common viral and bacterial rodent pathogens?

• Water samples from bottles
• Fecal pellets and serum from sentinel animals
• Feed samples
• Air samples from corridors

Correct Answer: Fecal pellets and serum from sentinel animals

Q16. What is the primary ethical justification for using the smallest number of animals necessary in an experiment?

• To reduce costs only
• To satisfy space constraints
• To comply with the principle of reduction in the 3Rs
• To simplify statistical analysis

Correct Answer: To comply with the principle of reduction in the 3Rs

Q17. Which condition in breeding cages indicates male aggression as a problem affecting colony welfare?

• Reduced cage changing frequency
• Ruffled fur, wounds, and barbering among cage mates
• Over-enrichment leading to hiding
• Increased nesting material usage

Correct Answer: Ruffled fur, wounds, and barbering among cage mates

Q18. What is the main advantage of monogamous pair mating compared with harem mating in small rodent colonies?

• Lower pregnancy rates
• Clear parentage for genetic studies
• Higher male reproductive stress
• Reduced need for record keeping

Correct Answer: Clear parentage for genetic studies

Q19. Which action is most appropriate when a facility discovers Mycoplasma pulmonis in a rat colony?

• Ignore, because it is non-pathogenic
• Implement a control or eradication plan with veterinary guidance
• Double cage density to dilute infection
• Switch to a different brand of bedding

Correct Answer: Implement a control or eradication plan with veterinary guidance

Q20. Which parameter is essential to record for each breeding pair to monitor reproductive performance?

• Color of the cage label
• Date of mating, date of birth, litter size and pup survival
• Technician’s favorite food
• Time of day the cage was cleaned last month

Correct Answer: Date of mating, date of birth, litter size and pup survival

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