Detailed with species differences among farm animals.

1. By: Dr.Arshaq Asfar

2.  Parturition is the physiologic process by which the
pregnant uterus delivers the foetus and placenta
from the maternal animal.
 Parturition comes from the Latin word parturire, "to
be ready to bear young one" and is related
to partus, the past participle of parere, "to
produce".

3. stages
Stage 1:
Cervical
dilation
Stage 3:
Expulsion
of the
placenta
Stage 2:
Delivery
of the
fetus
 3 stages:

4.  Changes not visible externally.
 Preparation of birth canal and foetus for expulsion.
 Signs of discomfort, mild colic, restlessness with
elevated pulse and respiratory rate, body temperature
falls.
 Structure of cervix changes.
 Onset of myometrial contractions.
 Foetus assumes the disposition for expulsion.

5.  Loosening of the ground substance due to changes in
the composition of collagen components.
(Fitzpatrick,1977)
 Increased incorporation of water which permits collagen
fibres to separate under extension forces.
(Fitzpatrick and Dobson,1979)
 Cervix dilates: external os opening before internal os
and becomes cone shaped due to wide dilation of
external os. (Abusineina,1963)
 Simultaneous shortening and internal os dilation.
 Vagina and uterus form continuous canal that becomes
tightly engaged by the distended allantochorion.

7.  Presence of cervicotubular and tubular-cervical
contractions. Gillette and Holm (1963); Taverne et al. (1979)
 Cervicotubular contractions prevent the premature
displacement of foetuses, thus ensuring orderly
expulsion from the horns. (Taverne et al., 1979)
 Isolated ,uncoordinated waves changes to regular and
coordinated peristaltic type.

8.  Frequency increases from 12-24 per hour in last 2 hours
to 48 per hour just before expulsion (30 per hour in
ewe). (Gillette and Holm 1963)
 Placental attachment becomes less intimate.
 Superficial cells undergo fatty degeneration.
 Separation of margins with haemorrhage in deciduate
placenta.

9.  Becomes more active and disposes itself.
 Progressive rotation from ventral to dorsal position and
fore limbs, head and neck extended in foal and puppy.
 In calf and lamb extension only.
 Flexed knees of calf first occupy dilating cervix; 30
minutes later digits are in cervix and it extends carpal
joints in its efforts to ‘stand up in utero’. Abusineina (1963)

11. Animal 1st Stage (hrs)
Cow, Buffalo 2-6
Mare 1-4
Ewe 2-6
Sow 2-12
Camel 2-7
Bitch 12

12.  Refers to expulsion of foetus.
 In polytocous species stage cannot be separated from
3rd stage.
 Sign: Apperance of abdominal contractions,
superimposed upon onset of each myometrial
contractions. (Gillette and Holm,1963; Zerobin and Spörri, 1972)
 Disappearance of cervicotubular contractions.
(Zerobin and Spörri, 1972)
 Ferguson’s reflex.
 Allantochorionic sac ruptures and gush of urine like fluid
escapes from vulva.

13.  Amnion traverses vagina and appears at vulva as
‘water-bag’ with foetal limbs.
 Foetal head next occupies vulva,contractions of uterine
and abdominal muscles reach climax of expulsive effort,
maximum effort coinciding with the birth of the foetal
occiput.
 Further straining causes foetal thorax to pass through
vulva.
 Usually, birth of hips quickly follows and hind limbs may
be expelled.

14.  Foetus is born in amnion and quick movement causes its
rupture; respirations, then begin.
 In mare, cow and ewe (when monotocous) foetus is
usually delivered in anterior presentation, dorsal position
and extended posture.
 In polytocous bitch and sow up to 40–45% of foetuses
may be normally delivered in posterior presentation.

15. 2nd stage of labour in the cow
1 2 3
4 5

16. 1 2
3 4
5 6
7 8
9 10
11 12

17. Animal 2nd Stage
Cow, Buffalo 70 min
Mare 17 min
Ewe 1 hr
Sow 4 hrs
Camel 30 min
Bitch 6-12 hrs

18.  After 2nd stage, regular abdominal contractions largely
cease. (Gillette and Holm, 1963)
 Myometrial contractions persist; decrease in amplitude.
 These contractions are important for dehiscence and
expulsion of fetal membranes.
 Waves of contractions passing from uterine tube to
cervix persist, but in cow and sow reappearance of
contractions in reverse direction.
(Zerobin and Spörri, 1972; Ngiam, 1977)

19.  Weakening of acellular layer of adhesive protein, ‘glue
line’ between cotyledonary and caruncular epithelium, is
probably important in ensuring placental separation.
(Bjorkmann and Sollen, 1960)
 In last 5 days of gestation collagenisation of placentome
and flattening of maternal crypt epithelium in cow.
Grunert (1984)
 Foetal villi have shrunk, owing mainly to sudden loss of
turgidity related to escape of blood from foetal side of
placenta when umbilical cord ruptures.

20.  Early degenerative or maturational changes which are
seen in caruncles of ewe and cow, cause separation of
fetal membrane.
 Apex of allantochorionic sac becomes inverted and as
sac is ‘rolled’ down cornua the fetal villi are drawn out of
crypts.
 This forms a mass within maternal pelvis which
stimulates reflex contractions of abdominal muscles
leads to expulsion of fetal membranes.
 Domestic animals normally eat afterbirth except Mare.

21. Cow
Mare

22. Eating of foetal membranes Foetal membranes along with placentomes

23.  In polytocous species,dehiscence and expulsion of fetal
membranes are interspersed with fetal births.
 Stimulus of suckling causes release of oxytocin, which
promotes ‘letdown’ of milk and augmentation of
myometrial contractions.
 Suckling resulted in greater synchrony of contractions
and increase in number of tubocervical contractions.
(Ngiam, 1979).
 Suckling exerts a favourable influence on expulsion of
afterbirth.

24. Animal 3rd Stage
Cow, Buffalo 6-12 hrs
Mare 30min-3hrs
Ewe 2-3 hrs
Sow 4 hrs
Camel 1 hr
Bitch Along with fetus or
shortly

25. Cow:
 Immediate approach of labour has been recognised by
slackening of pelvic ligaments and change of the
mammary secretion from a relatively transparent, honey-
like secretion to an opaque cellular secretion –
colostrum. Parkinson,T. J. (1993)
 Occasional straining may occur during 1st stage.
 Food is only picked; rumination is irregular; there may be
kicking at belly.

26.  Line of demarcation between first and second stages is
not clear-cut, as in mare.
 Umbilical cord is shorter in calf and its rupture generally
occurs as calf falls from vulva.

27.  Imminence of labour can be recognised by degree of
mammary hypertrophy, waxing of teats and possibly
escape of milk from glands.
 Best indication: onset of patchy sweating behind elbows
and about flanks 4 hrs before birth of foal.
 Tail is frequently raised or held to one side or slapping of
it against the anus and kicking at abdomen.
 Onset of 2nd stage occurs abruptly characterised by
appearance of amnion or commencement of forcible
straining. Pycock,J.F (1977)

28.  During its delivery, head is generally in oblique position;
it may even be transverse – cheek lying on the limbs.
 Separation of placenta tends to proceed rapidly once
second stage begins. Pycock,J.F (1977)
 Straining is not a feature of third stage.

29.  Imminence of parturition indicated by preparing bed.
 Transient drop in body temperature, 1.2°C within 24
hours before of parturition.
 40% of puppies born in posterior presentation.
 Umbilical cord intact at birth quickly torn by mother.
 Uterine discharge dark green in colour, due to
breakdown of marginal haematoma (‘green
border’).(Queen: brown coloration)
 Stage of expulsion of foetuses most irregular, tendency
for puppies to be expelled from alternate horns.
(Van der Weyden et al., 1989).

30.  60 to 75% of sows farrow at night. (Bichard et al., 1976;
Kovenic and Avakumovic, 1978)
 No separate 2nd and 3rd stage of labour.
 Several alternating periods of rest and bed-making and
in the hour preceding birth of first piglet, sow settles
quietly into lateral recumbency.
Jones(1966) and by Randall (1972)
 Offspring delivered randomly from both uterine horns.
Taverne et al.(1977)

31.  55.4% anterior and 44.6% posterior presentations.
Randall (1972)
 Mean interval between consecutive births is 16 minutes.
 Fetal membranes tend to be expelled as 2 or 3 masses of
joined allantochorions with placental stalks of umbilical
cords.
 Sow usually stands up and micturates profusely after
parturition.
 Early-born piglets are more likely to survive than either
middle-born ones or late-born ones from tips of the
uterine horns.(Dzuik and Harmon, 1969; Sprecher et
al., 1974; Leman et al., 1979).