2-Swine Reproductive Physiology Flashcards
(40 cards)
Swine reach puberty at what age
5 months of age.
breeding boars and gilts at ____ of age usually retards the growth and development of animals.
5 months
◼ Gilts should not be bred at not less than 225 days old (____ months) weighing around 120- 130 kg and have already cycled at least twice.
◼ Gilts that are ____, when bred usually produce small litter size and show poor maternal behavior to their young.
7 1⁄2 months
very young
the estrous cycle of sows and sexually mature gilts last for
18 to 42 days or an average of
21 days.
their estrus (heat period) or period of sexual receptivity, lasts for
2-5 days
Techniques in checking for sexual
receptivity (5)
- Haunch pressure test
- Riding-the-back test
- Semen-on-snout test
- Teaser boar method
- Tape recorder
◼Breed the gilt or sow on the first day she shows signs of accepting the boar.
◼Repeat breeding ____ hours after the first mating.
◼Breeding interval of ____ has little effect in litter size and conception rate.
12-24 hours
less than 12 hours
◼Breeding more than ____ during the same heat period has no added advantage over two matings.
◼Use the same boar for the first and second services for proper evaluation of boar performance.
◼Sows and gilts bred in the morning or in the afternoon should be bred again in the ____
twice
morning of the following day.
◼____ usually need more boar services than sows.
◼The conception rate is also higher for sows than for gilts.
◼Conception rate of __% may be considered as a good average for commercial herd.
Gilts
80%
◼Mature sows ovulate an average of ____ eggs every heat period.
16-18
Pregnancy or Gestation period
“3 months, 3 weeks and 3 days”
◼Most litters that farrowed before the ____ day of gestation are premature and not capable of living;
109th day
◼Heat period after farrowing (postpartum) occurs within the first __ days after delivery.
◼Sow should not be bred during this heat period for they will not get pregnant.
9 days
◼If the sow lost her litter for one reason or another, the sow may be bred during the postpartum heat which is usually delayed by about __ weeks
2 weeks
◼A sow needs ____ days from one
farrowing to the next (farrowing interval).
145-163 days
Litter size at birth ranges from ____ pigs.
A normal piggery may expect an average of ____ pigs at birth including stillbirths.
An average of ____ pigs at birth suggests some management problems in the herd.
A newly established piggery with all gilts however, may expect an average litter size at birth of around __ pigs only.
1 to 27 pigs
10 or more
less than 9
9
what hormone is responsible for the recruitment and development of
follicles.
Follicle Stimulating Hormone (FSH)
mainly responsible for ovulation of the oocyte and together with FSH are responsible for follicle maturation.
Luteinizing hormone (LH)
what hormone is mainly responsible for the manifestation of “heat” or sexual receptivity in animal.
Estrogen
what hormone is secreted by the dominant follicle which suppresses the
secretion of FSH.
Inhibin
What hormone is secreted by the corpus luteum (CL) and
responsible for the maintenance of pregnancy in the animal.
Progesterone
what is secreted by the uterus and responsible for the lysis of the CL in the absence of pregnancy and it initiates parturition.
Prostaglandin f2 alpha (PGf2ɑ)
what hormone is responsible for uterine contraction and milk-let- down.
Oxytocin
Secretes gonadotropins in response to GnRH
▪ FSH Follicle Stimulating Hormone
▪ LH Luteinizing Hormone
Source of OXYTOCIN
what gland
The Pituitary
