Breeding and Reproduction Flashcards

Which condition describes a female mouse that shows signs of pregnancy (including a vaginal plug) but is not actually pregnant?

Answer: Pseudopregnancy

Pseudopregnancy occurs when ovulation happens without fertilization, causing hormonal changes that mimic pregnancy.

What is the primary purpose of using a 'vasectomized male' in a rodent breeding program?

Answer: To induce pseudopregnancy in females for embryo transfer

Vasectomized males mate with females to induce pseudopregnancy, preparing the uterus for embryo transfer without producing offspring.

At what age are female rats generally first bred in a laboratory setting?

Answer: 8-10 weeks

Female rats are typically first bred at 8-10 weeks of age when they have reached sufficient body maturity.

Which hormone surge triggers ovulation in cats, making them induced ovulators?

Answer: Luteinizing hormone (LH)

In induced ovulators like cats, the mechanical stimulation of mating triggers an LH surge that causes ovulation.

In laboratory animal breeding records, 'D.O.B.' refers to:

Answer: Date of Birth

D.O.B. stands for Date of Birth and is a critical data point for tracking animal age, breeding eligibility, and study enrollment.

What is 'cross-fostering' in laboratory animal breeding?

Answer: Transferring pups from one dam to another to equalize litter sizes or improve survival

Cross-fostering involves moving neonates from their biological dam to a surrogate dam to improve survival odds or balance litter sizes.

Which of the following is a sign that a female hamster is in estrus and receptive to mating?

Answer: Lordosis posture (arched back, immobile stance)

Lordosis — a rigid, arched-back posture — is the characteristic receptivity signal in female hamsters during estrus.