Reproduction Flashcards
Describe ferret breeding seasonality and ovulation.
Season in northern hemisphere from March to August for females. December to July for males.
Induced ovulators that respond to increasing day length.
When do ferrets born in late spring or early summer and maintained under natural lighting start to cycle? Those maintained under artificial illumination?
Natural: Not until the following season
Artificial: If maintained at 8h light-16h dark, puberty at 10-12 months.
The transfer from short to long photoperiod should not occur before what age? Why?
90 days, because jills that are prematurely transferred will remain anestrous.
What is the minimum breeding age of males and females?
Male: 8-12 months
Female: 4-5 months
What is the hallmark of estrus in jills?
Vulvar swelling.
How long is proestrus? Is estrus onset associated with elevated serum hormone levels?
2-3 weeks. Not associated with elevated FSH as in the ferret.
How can estrus terminate? (5)
- Coitus-induced ovulation and pregnancy
- Pseudopregnancy after infertile mating
- Pharmacologic termination (hCG, GnRH, or GnRH analogs)
- Death due to estrogen-induced aplastic anemia
- Spontaneous remission and anestrus due to reduced photoperiod.
When are females and males brought together for mating? For how long?
Females brought to males approx. 14 days after vulvar enlargement. Copulate many times and for prolonged periods of time and typically left together for 2 days.
A surge in what hormone accompanies coitus?
Surge in LH in females, not in males.
When does implantation occur? What is required for implantation and maintenance?
12 days after mating.
Functional CL and anterior pituitary
What type of placenta do ferrets have?
Typical of carnivores - Zonary and endotheliochorial
When and how can pregnancy be detected?
By US on day 12, palpation on day 14, and radiographs by day 30
What is required for induction of ovulation? (2)
Intromission and neck restraint by male
When should jills be socially housed prior to pregnancy? What should they be provided?
Within 2 weeks of parturition. Provided a secluded place to deliver kits.
Describe ferret nest boxes.
Should contain bedding. At least 6 inches deep and prevent kits from wandering. Smooth entrance to prevent damage to teats and mammary gland.
How is feed and water provided to the jill during lactation?
Most jills will leave the nest box to eat and drink. If she will not leave, low-sided food bowls should be placed in the nest box.
During pregnancy, ferret fetuses have a large demand for what compound? How is it provided? What occurs if fetal demand and maternal supply are imbalanced? Why would imbalance result?
Glucose, supplied by mother. Imbalance from fasting or increased nutritional demand of rapidly developing fetal placental unit can cause females to suffer from negative energy balance and succumb to severe hypoglycemia.
How long does parturition take?
Rapid, as little as 2-3 hours
When do primiparous and multiparous jills deliver?
Primiparous - Day 41
Multiparous - Day 42
What are signs of impending labor?
Few signs, but abdominal enlargement and mammary development do occur in the last week or two
What factors may delay parturition? (2)
Small litters (<3) and kits with congenital malformations
What should be done with jills past their due dates? At what point are in utero fetuses typically deceased?
Palpate for fetuses.
Day 43
Why is dystocia common in ferrets? Describe treatment?
Positional abnormalities and fetal oversize. If small litter size to blame, treat with prostaglandins and oxytocin. If no kits within 8 hours, C-section.
Why might a jill not allow her kits to nurse?
May not allow kits to nurse until all kits are delivered. Jills not attentive to their kits should be palpated for additional fetuses.
