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Feline Reproduction

Parturition

  • Milk may be obsereved just prior to parturition - uncommon
  • Prepartum rectal temperature drop - is not obsreved

  • Posterior presentation is common, does not predispose to dystochia

Pregnancy

  • Ovulation follows coitus by 24-30 h
  • Fertilisation in oviduct
  • as morulae pass into the uterine horn by day 4-5 postcoitus
  • superfecundation

  • Transuterine - intercornual migration
  • Implantation - 12-13 (14-16) days after ovulation
  • Endotheliochorial (4 layer) placenta zonaria

E2

  • remains low during the first 35–40 days of pseudo-pregnancy similar secretion pattern, with higher values, is observed during pregnancy
  • in the second half of gestation E2 concentrations start to vary, commencing with decreasing P4 concentrations, and increase toward parturition > Estrus behavior

Feline placenta is capable of producing both P4 and E2

Intraplacentally produced P4 has a supplemental role with mostly local effects

Relaxin becomes detectable at about day 20–25 of gestation

PRL is elevated during the last one third of pregnancy

During pseudo-pregnancy, PRL remains generally at basal levels

ICC in queens: DBP = (mm – 62.03)/1.1

BP in queens: DBP = (mm – 23.39)/0.47

  • Short partial anorexia, vomiting
  • First 3-4 weeks > minimal weight gain - Queens should be fed a normal prebreeding ration
  • 4-6 weeks - Caloric intake should be increased gradually about 50%
  • Final weeks -70%, maintain the optimal body condition

underweight - maintaining lactation

obesity - dystochia

Proestrus

Estrus

1-3 days

7 (3-16) days

  • Begins - the queen allows to mount and breed
  • Behavioral stage of receptivity to mating
  • Occurs during peak follicular activity and E2 secretion
  • Lordosis, tail deviation, head rubbing, vocalization
  • Observed only a minority of queens
  • Rubbing of the head and neck against of any convenient object
  • Vocalizing and rolling on the ground
  • Not permit breeding, nonreceptive - Attracts the toms but refuses

  • Rising serum estradiol (granulosa cells of the ovarian follicles)
  • Effect on vaginal epithelium >
  • increased number of epithelial cell layers
  • vaginal cornification > the proportion of anuclear superficial cells increases (10%)
  • Vulvar labia are nonresponsive to E > remain small
  • Not observed - vaginal bleeding

Peak vaginal cornification occurs at time of peak E2 concentration

Anuclear squames 10% >> 40% (by the 4. day)

Mating

5-50 sec - Mounting and grasping of the neck by male

0,3-8 min - Positioning

1-30 sec - Intromission, ejaculation, queen's coital cry

0-1 sec - Dismounting

1-7 min - Queen's after-reaction > disoriented rolling, stretching, genital licking

21 days

Anestrus

3 months

Interestrous

10-14 days

Puberty

  • The puberal estrous occurs 6-9 months of age
  • incfluenced by
  • Time of year/photoperiod
  • Body condition - at least 80% of adult body weight (2,3-3,2 kg)

  • Oriental breeds (Siamese, Burmase) - very young age
  • Longhaired and Manx - later onset of puberty (11-21 months)
  • in queens that have not been induced to ovulate, Ø CL
  • low E2, P4
  • no sexual behavior or receptivity

Occasionally, queens appear to miss an interestrous

  • estrous behavior persist during two or more follicular than interestrous phases
  • cyclic E fluctuations -but the lowest E conc. remained above the 20 pg/ml

((Metestrus))

Pseudopregnancy

1-3 days

30-35 days

  • During estrus
  • Morphologic evidence of CL development

Reesthabilishment of ovarian activity can begin 7-10 days following luteolysis in both pregnant and pseudopregnant queens

Lactation and suckling of kittens may cause lactatioanal anestrus > 2-3 weeks after weaning

  • Diestrus - time of functional corpora lutea
  • P4 dominance
  • Ovulation, Ø fertilization
  • Luteal phase of nonpregnant queen is one-half the duration of the normal gestation period

  • Spontaneous ovulation - without male contact
  • Infertile copulation
  • Artificial stimulation of the vagina by probing with cotton swab > induce ovulation

No clinical signs

40-45 days "rest period"

P4

is similar in pregnant and pseudo-pregnant cats until days 10–12 of g., when implantation takes place in pregnant

  • increase dynamically, reaching peak values (~30–40 ng/ml) at day 21.
  • thereafter, gradual decrease toward parturition

in pseudo-pregnancy

  • similar initial P4 secretion - peak levels > lower than during pregnancy, followed by a gradual decline (dropping to <1 ng/ml) by days 36–46
  • the luteal phase in pseudo-pregnant cats lasts about half of its length in pregnant queens

Luteal regression/luteolysis during pseudo-pregnancy appears to be a passive degenerative process in the absence of a luteolytic principle of uterine origin

Prepartum luteolytic mechanism > signifi cant increase in fecal and serum PGF2α

This placental signal is missing in pseudopregnant queens

Mariusz P. Kowalewski (2017)

Pregnancy

63-65 days

meaning that they can go into heat several times during a season,

repeatedly exhibits estrus behavior in a given season

Seasonally polyestrous

  • Cycles repeatedly throughout a breeding season
  • Northern hemisphere -January/February with gradual frequency decline until September/October
  • Anestrus from November until end of January
  • Hot summer, stress - interrupts
  • Hours of daylight - major impact on the onset and the duration of ovarian activity

Long-day breeders, are sexually active in spring and summer.

Prolonged anestrus results from decreasing or short day length (< 8h/day)

Senger, 2012.

When the photoperiod is shortened, melatonin and PRL secretion are enhanced > reducing ovarian function

14h/day

~16 day

12h/day+

interrupted darkness

~16 day

12h/day +

social stimuli

~21 day

Induced ovulator - by coitus

  • Vaginal stimulation is transmitted via spinal afferent nervous pathway to HT> increased neural activity > GnRH release > LH peak
  • LH correlated with the number of copulation, max LH - 4h after 8-12 copulations
  • about 50 % of queens ovulating after a single copulation
  • Most queens do ovulate following 4 (or more) copulation
  • Ovulation occurs 24h after the LH peak
  • number of matings does not influence the number of ovulated follicles

Spontaneous ovulation - with incidence ranging from 35% up to 87%

dr. Linda Müller

clinical veterinarian

Department and Clinic of Reproduction

University of Veterinary Medicine

Angelika von Heimendahl, Gary C. W. England 2010., BSAVA Manual of Canine and Feline Reproduction and Neonatology

Placental production of P4

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