veterinary Theriogenology I note (1).pdf

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Theriogenology-I
Alemayehu (PhD)
Oogenesis and Ovulation
• General Events
– Maturation of oocyte cytoplasm & nucleus
– Cumulus oophorus & oocyte free of granulosa cells
– Follicle wall thins & ruptures
• Specific changes
– LH-FSH surge stimulates meiosis I to start again in preovulatory
oocyte.
– LH surge causes increase in follicular fluid - (edema) follicle
swells and makes granulosa to produce progesterone
– Enzymes in follicle begin breaking down the follicle wall.
– Collagenase attacks collagen in theca externa and tunica
albuginea
– Maximum number of oocytes ovulated for a cow 17 cycles/year
x 8 year = 136 oocytes ovulated/lifespan
• During natural mating, semen is
deposited in the anterior portion of
the vagina
• When a cow is bred, either
naturally or by artificial
insemination, the uterine muscles,
under the influence of hormones
oxytocin and estrogen, rhythmically
contract to aid in sperm transport
to the oviducts
• The UTJ functions as a filter of
abnormal sperm and the isthmus as
a reservoir for healthy sperm
Capacitation and Fertilization
• Upon gaining access to the isthmus, healthy
spermatozoa attach themselves to the walls. During this
period of attachment, many physiological changes occur
to sperm membranes, which are essential to attainment
of fertilization potential
• These changes are collectively referred to as capacitation and are
apparently regulated by this very important attachment to the walls
of the isthmus
• Capacitation of sperm - A biochemical change to sperm
that allows the true acrosome reaction to occur
• Time for capacitation : Pig 3 hrs, Ewe 1-2 hrs, Cow 5-6hhr,
Horse ?
• Glycoproteins from epididymis coat the sperm; Oviductal and
uterine fluid remove coat and allow capacitation
Capacitation and Fertilization

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Hair like structures on the infundibulum and within the ampulla
rhythmically beat to move ova and a surrounding mass of cells
called the cumulus mass down the oviduct to the site of
fertilization

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Fertilization - YouTube (360p).mp4
Spermatozoa_motility_01.mp4
Prevention of Polyspermy and Polyploidy
• Oocyte blocks to polyspermy
– Zona reaction
– Vitelline block
• Mechanisms of blocks
– Sperm attaches to vitelline membrane
– Cortical granules fuse to vitelline membrane and release
contents
– Cortical granule components alter zona/Vitelline
membrane, i.e. makes it less penetrable by sperm
– Species variation
• Zona reaction most important in sheep and dog
• Vitelline block most important in rabbits

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– Factors causing decreased effectiveness of blocks to
polyspermy:
• Age of ova
• Heating ova
• Excessive sperm numbers
• Coordination of events for fertilization to occur,
i.e. Time of breeding relative to ovulation.
– Optimize sperm transport and reservoir formation
– Breed early enough for capacitation - If too early,
sperm will die before the oocyte is in the oviduct
– Breed late enough so fertile life span of sperm and
oocyte overlap
Prevention of Polyspermy and Polyploidy Ova
(hours)
Sperm
(hours)
Length of
Estrus
Timing of
Ovulation
Timing of
Insemination
Cattle
20-24 30-48
12-19 hours 10-11 hours (after
end of estrus)
6-12 hours (after
onset of estrus)
Horse
6-8 72-120
2-7 days 1-2 days (before
end of estrus)
2nd day of estrus
and every 2 days of
rest of estrus.
Sheep
16-24 30-48
24-36
hours
24-36 hours (after
onset of estrus)
12-18 hours (after
onset of estrus)
Swine
8-10 24-72
48-72
hours
35-45 hours (after
onset of estrus)
16-24 hours (after onset
of estrus)
2nd insemination 8-24
hours
after 1st insemination.
Development of the zygote (Early Embryogenesis)
• Gestation is the period of pregnancy. It starts with
fertilization and ends with parturition. When male
and female pronuclei can be observed, the cell is
called Ootid.
• The ootid has an enormous cytoplasmic volume
relative to the nucleus. Following fusion of the male
and female pronuclei, the embryo is called the
zygote.
• The zygote undergoes a series of mitotic divisions.
This proccess of cell division with out growth is called
cleavage. The cells are called blastomeres
• The mitotic divisions of each blastomere generally
occur simultaneously. More cleavage results in 4-cell,
8-cell, 16-cell, 32 cell embryos etc. With each
cleavage, the blastomeres become smaller.
• The 8- to 16 cell stage embryo is called a morula. By
the 32- to 64-cell stage, the morula will be compact
with gap junctions forming between cells and tight
junctions forming between cells on the outside of
the embryo

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• The inner cell mass will develop into the embryo
proper and the trophoblastic cells will eventually
give rise to the chorion.
• The chorion will become the fetal component of
the placenta. As the blastocyst expands, it will
press against the zona pellucida causing it to thin.
• Then a small crack or fissure in the zona pellucida
develops, and the blastocyst escapes (hatch) from
the zona. The blastocyst now becomes a free-
floating embryo within the lumen of the uterus
• After entry into the uterus, embryos migrate freely
between days 10 -16 in most animals. Afterwards, the
embryo will become settled at one location, a process
called Implantation.
• Implantation is the process by which chorionic villi
extend in to the endometrium forming a union.
• After hatching, the conceptus undergoes massive
growth. Eg, in the cow at day 13 the blastocyst is about
3mm in diameter. In the next four days (day 17), the
blastocyst will become 250 mm in length. By day 18,
the blastocyst occupies space in both uterine horns
Maternal Recognition of Pregnancy
• Maintenance of pregnancy is largely dependent on a
proper balance of hormones. Progesterone has a dominant
role in maintenance of pregnancy particularly during the
early stages. In the absence of pregnancy, the
endometrium will produce PGF that will destroy the CL.
• The embryo must communicate its presence to the
maternal system to prevent luteaolysis. The biochemical
process by which the embryo signals its presence is termed
as Maternal Recognition of Pregnancy.
• In cattle and sheep, the embryo produce a protein called
interferone-τ (INF- τ, bovine and ovine, respectively). These
proteins have anti-luteolytic properties through alteration
of PGF biosynthesis and regulation of uterine oxytocine
receptors

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Embryonal
Blastocyst
CL
Follicle
ER
Oxytocine
Receptore
Oxytocine
Estrogen
Interferone-τ
Uterine
Endometrium
PGF2α
PGE2
Extra Embryonic Membranes and Placentation
• The dramatic growth of the conceptus is due largely to the
development of a set of membranes called the
extraembryonic membranes.
• Formation of the extraembryonic membranes is an obligatory
step in the acquisition of the embryo's ability to attach to the
uterus of the dam.
– The trophoblast gives rise to the chorion and the amnion.
– The yolk sac develops from the primitive endoderm.
– The chorion will eventually attach to the uterus, while the
amnion will provide a fluid filled protective sac for the
developing fetus
• During the same time that the amnion is developing,
a sac-like evagination, the allantois from the
posterior region of the primitive gut. The allantois is
a fluid filled sac that collects liquid waste from the
embryo.
• Toward the end of gestation the volume of allantoic
fluid varies from 4000 to 15000 ml, averaging about
9500 ml, in the cow.
• As the embryo grows, it eventually will make contact
with the chorion and fuses with it forming the
chorioallantoic (allantochorionic) membrane.
• The chorioallantoic membrane is the fetal contribution to the
placenta and will provide the surface for attachments to the
endometrium.
• In ruminants the maternal placenta (caruncles) and the
allanto-chorion (cotyledons) form the placentome. There are
between 75 and 120 placentomes in the cow.
• Both relative rate of growth and formation of organs proceed
rapidly during differentiation. After differentiation, the
conception is called Fetus. Fetal size is affected by sex (males
are heavier than females), and stage of gestation (over half of
the total weight is gained during the last two months of
gestation in ruminants)

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Age of conceptus Crown-rump length
30 days 1 cm
60 days 5 cm
90 days 13 cm
120 days 30 cm
150 days 38 cm
180 days 56 cm
210 days 71 cm
245 days 81 cm
280 days 86 cm
Average size of bovine conceptus at different ages
Animal 1cell
(Hrs)
8cell
(Days)
Morul
a
(Days)
Blastocy
st
(Days)
Enter
Uterus
Placentat
ion
(Days)
Gestatio
n
(Days)
Cow 24 3 4-7 7-12 3.5d 30-70 280
Sow 14-
16
2 4-5 6 2d 12-24 114
Ewe/
Doe
24 2.5 4-5 7 3d 15-30 148/149
Mare 24 3 4-5 6 5d 24-45 337
Pregnancy diagnosis
• Transrectal Palpation
• Ultrasonography
• Detection of hormones and proteins in body
secretions (blood, urine, milk, saliva)
• On Farm Implementation of Early Non-
pregnancy detection
Methods of pregnancy diagnosis
• Transrectal Palpation
– Transrectal palpation is a widely used method for
early PD in dairy cattle today
• palpation of the uterus, amniotic vesicle, cotyledon, CL
• slipping of the chorioallantoic membranes between the
palpator’s thumb and forefinger beginning on about day
30 of gestation
– the risk of iatrogenic pregnancy loss
– widespread use, high accuracy, and relatively low
cost per animal
AV_FMS.mpeg
videoplayback.mp4 Pregnancy Diagnosis in Bovine Determination of Pregnancy Per-rectal examination(0-9 month preg.).mp4

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• Transrectal Palpation: The rectal diagnosis of the
gestation is based on a series of signs or symptoms that
allow to confirm or to exclude the pregnancy after the
35 days:
• 1 - Situation, retraction, and weight of the uterus.
• 2 - Asymmetry, consistency of the wall and fluctuation of
the uterine horns (ballottement)
• 3 - Presence of the fetal membranes.
– a) Presence of the amniotic vesicle or sack.
– b) Allantochorion (double wall - membrane slip).
• 4 - Presence of the placentomes.
• 5 - Presence of the fetus.
• 6 - Changes of the middle uterine artery (Fremitus)
• B-Mode Ultrasonography
– Ultrasound is a less invasive technique for early PD and may
minimize the rare incidence of palpation-induced abortions
– Accurate diagnosis can be made as early as 26 d post AI in
cow and 10 d in mare
– Additional information gathered using the technology
include evaluation of ovarian structures, detection of twin
fetuses, and of fetal sex
– Foetal heartbeat can be visualized at around 21 d of
gestation
– Represents definitive characteristic for positive confirmation
of a viable pregnancy
B
A C
15 day
22 day
35 day

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Image of bovine foetus: A) a female foetus at 65 days of gestation; and B) a saggital view
of a male foetus at 65 days of gestation
Ultrasound image of bovine foetus: A) Male foetus and B)
Female foetus
• Detection of hormones and proteins
– Progesterone assay – milk, plasma, serum
– Pregnancy specific protein B
Methods of pregnancy diagnosis Parturition
• Events just prior to parturition:
1. Pelvic ligaments soften - Tail head sinks due to estrogens
and relaxin.
2. Cervix softens and begins secreting stringy mucus -
estrogens and relaxin.
3. Swelling of vulva.
4. Udder swells - fills with first milk and due to edema:
5. Fetus moves into proper position - resting on thorax,
front feet and head facing the cervix.
6. In some species of domestic animals there is a change in
the maternal behaviour like preparing a bedding or nest
or hiding place (sow, bitch etc)
7. There will be inapettance, restlessness

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• There are different speculations:
– Accumulation of waste and CO2 - irritate the uterus
– Increased volume and weight of the foetus -more pressure
• Factors that regulate plasma P4 are significant in
controlling the length of gestation
o Fetal ACTH causes -
 Fetal Corticosteroids causes -
  Progesterone levels
( placental production or CL regression) -
 Production of Estrogens by placenta –
 PGF2a production by uterus -
What initiates normal parturition
• Initial hormonal changes is significantt.
– Progesterone - removes block on uterine contractions.
– Estrogen - makes uterus more responsive to induction of
contractions i.e., more irritable and smooth muscle
tissue stimulation.
• Foetal factor (Foetal-Pituitary-Adrenal-System) play a primary
role in the initiation of parturition.
• As the foetus mature the pituitary gland produce ACTH. This
stimulate production of oestrogen by the placenta.
• Then PGF2 will lead to luteulysis and a decline in progesterone.
• Oxytocin is also released which result in more contraction of
the uterus.
• The foetus determines the days while the dam determine the
hours of parturition.

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Stages of parturition:
• Stage-I or dilation of cervix, (2-6 hours, cow)
o The first stage of labor is the preparation for birth.
Coordinated uterine contractions (estrogen & PGF2a
induced).
o Fetus pushed against cervix - amnion dilates cervix.
• Allanto-chorion may break.
• Relaxation of pelvic ligaments and associated
structures
• The cervix, vagina and vulva all dilate and the cervical
mucous plug is released to facilitate the passage of the
calf
• Interference before this stage is completed should be
avoided
• Stage-II or expulsion of the fetus through the birth
canal.
• The start of the second stage of labor is signaled by the
appearance of the water bag
• Duration of this stage lasts from 0.5 hr to 3h. A cow or
heifer should be given no more than 1 hr after the water
bag appears before being checked to see if she needs
help
• Pressure of fetus in cervix stimulates oxytocin release
and reflex contractions of abdominal muscles
Stages of parturition:
• Strong uterine contractions due to synergistic actions of
high estrogen, PGF2a and oxytocin
• Strong abdominal muscle contractions.
• Amnion ruptures - mucin lubricates vagina - vestibule
• Fetus passes through vagina - vestibule.
• Stage-III or Expulsion of the fetal membranes (placenta)
and involution of the uterus (getting ready for the next
pregnancy) comprise the third stage of labor
• The time from expulsion of the placenta up to the non-
pregnant state of the uterus is called Puerperium .
Stages of parturition

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• Physiological processes during purperium are
– Regeneration of endometrium: involve the removal of
lochia and re-growth of the endometrium. This takes 3-4
weeks in the cow, 13 -25 days in mare.
– Involution of the uterus: this involves the reduction of size
of the uterus. There is extensive enzymatic activity in the
cells making up the uterine wall. The time required are 45 d
-cow, 25 d mare, 30 d -ewe and 21 d-bitch.
– Resumption of ovarian cycle: dairy cows 30-72 days, beef 30
- 140 days, mare 6-13 days, ewe 30 days, sow 3-5days. Some
additional days In suckling animals.
• Elimination of possible bacterial contamination of the
uterus
Stages of parturition
• Bovine Abortion
• Abortion - expulsion of dead or live conceptus incapable of
independent life;
• Premature delivery - preterm birth of immature viable fetus;
• Stillbirth - dead fetus expelled at term
• A single isolated case may not warrant a full investigation. A
thorough, objective history should be taken along with a good clinical
exam. The success rate of positive diagnosis is ~ 25%.
• Abortion is often the result of prior events and the cause is often
undetectable by the time of the abortion. Toxic and genetic factors
are not always discernible in available specimens. Many causes are
unknown
Diseases and accidents of gestation
• It would be helpful to be able to estimate how long a fetus has been
dead
• Estimation of the length of time: 12 h - cloudy cornea; 24 h - kidneys
soft and pulpy, abomasal contents cloudy, mucoid, and flocculent; 36-
96 h - subcutis gelatinous and reddish or blood tinged; liver soft and
friable; abomasal contents reddish
• Types of Abortion: Non-infectious abortion
–Genetic: The majority occur before pregnancy is diagnosed,
–Nutrition: is seldom a cause of abortion but does result in dystocia
and the birth of weak calves. Vit A, I and Se deficiency.
–Environmental: High maternal body temperature results in
profound fetal hypotension, hypoxia and acidosis.
–Physical: trauma is an unlikely cause of abortion. Palpation of the
amniotic vesicle/fetal m/ms in early gestation can result in abortion
• Infectious abortion
• Infectious Bovine Rhinotracheitis (IBR) – caused by bovine herpesvirus
• Mycobacterium bovis - generally associated with infertility. M.
bovigenitalium occasionally causes abortion.
• Ureaplasma sp. - occasionally cause of abortion (during the last
trimester), cause placentitis and fetal pneumonitis
• Salmonella (Eg. S. dublin, occasionally other serovars) may cause abortion.
• Haemophilus somnus: occasionally causes abortion with retained
placenta at 7-9 months of gestation. Listeriosis (Circling Disease, Silage
Sickness) is caused by L. monocytogenes.
• Mycotic: Fungi are estimated to be the cause of 2 to 30% of all infectious
abortions. Two-thirds of mycotic abortions are due to Aspergillus
fumigatus. Other species of fungus implicated in bovine abortion include
Mucor, Rhizopus, Absidia and Mortierella. The source of infection is
usually external via the respiratory or GI route

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• Chlamydia : Chlamydia are obligate intracellular bacteria. They are
susceptible to TTC. Abortions occur without clinical signs as early as 5m of
gestation but usually occur in the last trimester. Retained placentas are
common. Abortions are usually sporadic. The route of infection is via
ingestion of tissues. Rebreeding problems are common after abortion
• Epizootic Bovine Abortion commonly known as Foothill Abortion is a vector
transmitted disease. The etiologic agent is unknown. The vector is the
argasid tick, Ornithodoros coriaceus. Last trimester abortions are seen
• BVD: The etiologic agent is a Pestivirus in the family Togaviridae. The virus
can infect many species. The virus is shed in feces and nasopharyngeal
secretions. It is transmitted by aerosol droplets and by the oral route from
fecal contamination
• Leptospirosis: The etiologic agent is a spirochete, Leptospira interrogans,
which has over 180 serovars in 19 serogroups. Each serovar is adapted to a
particular reservoir host but can cause disease in any mammalian species.
After a 4 to 10d incubation period, they disseminate to many organs in a
leptospiremic phase lasting up to 7d. During this period, acute clinical
disease may be seen.
• Acute disease is most commonly manifested as mastitis in dairy cows.
Chronic infection is manifested as abortion, stillbirth, and the birth of
premature and weak infected calves. Retained fetal membranes are
common after hardjo abortion. Abortion may be the only manifestation of
infection or may be related to an episode of illness
• Administer tetracycline for treatment of acute infection. Control is achieved
through hygiene and vaccination
• Neosporosis : This was first identified as a cause of abortion in 1989. The
etiologic agent is a protozoa of the genus Neospora. The life cycle is probably
similar to Toxoplasma gondii (i.e. oral route of infection with transplacental
infection of the fetus; carnivore sheds oocysts in feces; oocysts are ingested
by cattle, sheep and goats; carnivore eats cattle, etc).
• Abortion occurs at 3 to 8 m (usually 5 to 6) of gestation. Gross lesions are
non-specific and the fetus is usually autolyzed. There is usually no metritis or
RFM after abortion. Occasionally the calf is born alive with hind limb
weakness or paralysis, with a poor prognosis
• There is no known treatment for the disease. Prevention is by protecting the
feed and water from fecal contamination and fecal contact
• Brucellosis : The species affecting food animals are Brucella abortus cattle,
elk, bison; B. melitensis goats and sheep; B. suis swine and reindeer.
Transmission is by the oral route (B. Abortus and B. melitensis); oral and
genital route (B. suis in swine); and oral route (B. suis in reindeer).
• Dropsy of FM: hydrallantois and hydramnios
• Hydroallantois, or hydrops of the allantois, is due to a defective placenta
(the chorio-allantois). The fetus is normal.
• The condition is characterized by a rapid accumulation of watery, clear fluid,
usually in the last trimester.
• The cow is rounded in the caudal view, and you normally can't palpate the
fetus or placentomes.
• Usually the condition results in a sick cow with anorexia, decreased rumen
motility, dehydration and weakness.
• The cow may be down; If the cow survives, postpartum metritis is common
• The placenta is thick.
• The condition usually ends in death or intervention.
• The prognosis is guarded to poor for life and fertility.
• Treatment consists of Caesarian section with a slow drainage of fluid and
perioperative support. Dexamethasone can be used if the cow is not down.

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• Hydramnios, or hydrops amnios, is due to a defective calf,
usually attributed at least partly to a defect in swallowing.
– The placenta is normal.
– The condition is characterized by a gradual accumulation of thick, viscid
fluid during the last half of gestation.
– The cow has a pear shaped caudal view.
– Usually you can palpate the fetus and placentomes.
– The cow is clinically otherwise unaffected.
– The pregnancy usually goes to term, and frequently a small, deformed
fetus is delivered.
– Postpartum metritis is uncommon.
– The prognosis is good for life and fertility.
– No treatment is required.
– The cow may be allowed to go to term or induced to calve.
• Uterine torsion : usually occurs near term and is found at parturition because
of the subsequent dystocia.
• Diagnosis can be made by a number of ways.
– By manual vaginal exam, the vaginal wall can be felt to be twisted
or spiraled. This can be visualized with the aid of a speculum.
– By rectal exam, the broad ligaments can be felt to be crossed and
the uterus twisted.
• It is important to determine the direction of the torsion during the
examination.
• When correcting a dystocia, if the calf is found upside down (dorso-
pubic), consider the possibility of a uterine torsion.
• Alternatively, the torsion may be corrected manually by rocking the
fetus until enough momentum is achieved to flip the uterus.
• If the cervix is closed other methods must be employed such as the
surgical (C-section) correction.
• Fetal mummification occurs in cases of fetal death without involution of the
CL and fetal expulsion, followed by autolytic changes, absorption of the fetal fluids
and involution of the placenta.
• In cows the maternal caruncle involutes and hemorrhage occurs between the
placenta and the endometrium, leaving a reddish-brown, gummy mass that imparts a
reddish brown color to the mummified fetus.
• The etiology is varied and ranges from infectious causes such as BVD, leptospirosis,
etc. to non-infectious causes such as genetic, compressed umbilical cord, etc.
• Diagnosis is based on the presence of a CL, the lack of fremitus in the uterine artery
and lack of fetal fluid in the uterus. The fetus feels dry and mummy-like on palpation.
Oftentimes the head, ribs, etc. can be felt.
• Prognosis is good if the fetus is removed. After the fetus is removed, conception
usually occurs 1-3 mo. later.
• Treatment is accomplished by administering PGF2a (with or without estrogen) to lyse
the CL. Steroids are ineffective with dead fetus and non-functioning placenta. After
treatment, check the vagina because sometimes the mummy may be lodged in the
vagina when expelled

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• Fetal Maceration : results from death of the fetus followed by dilation of the cervix
and incomplete abortion or dystocia, usually during the last half of gestation. This
condition can be due to a variety of miscellaneous organisms.
• Diagnosis is by rectal palpation, the uterine wall is thick, little or no fluid is present in
the uterus and you may be able to palpate fetal bones and pus, or bones crepitating
against each other in the uterus.
• Prognosis : The prognosis is poor for cows with this condition. This is not a "retained
CL" problem so lysis of the Cl is not helpful. Endometrial damage is present even if all
fetal parts are removed.
• Treatment is very difficult. The cervix cannot usually be dilated sufficiently to
remove all the fetal parts and any remaining fetal parts act as an IUD. Surgery has
been performed in valuable individuals.
• Postpartum Period: Time from parturition to 1st fertile
estrus. Different animals exhibit different reproductive
activity
– Sows have infertile estrus 3-10 days postpartum and show 1st
fertile estrus after weaning.
– Ewes have non-fertile estrus 21 days postpartum, and show 1st
fertile estrus after 40 days.
– Mares show foal heat 5-15 days postpartum (Lower fertility) and
the next estrus 45 days postpartum.
– Cows show the 1st estrus 30-40 days postpartum in dairy cows and
40-60 days in beef cattle.
• The period before and after calving is the most stressful in
a cow's reproductive life. The complications listed below
often appear in combination, along with reproductive
infections such as metritis, to make up what has been
described as a "postpartum disease complex."
Diseases and accidents of postpartum period

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• Retained placenta, Uterine prolapse, Displaced abomasum
(with in 1mth of parturition), Ketosis, Acidosis are some of the
postpartum complications. Ketosis results from the metabolism
of fats. It is usually associated with a depressed appetite due to
metritis, mastitis or abomasal displacement. The most effective
management strategy for ketosis, acidosis and laminitis is
prevention through providing proper nutrition before and after
calving
• Factors Affecting the Postpartum Period:
– Body condition pre- and postpartum
– Plane of Nutrition
– Lactation stress
– Suckling stimulus
– Photoperiod
– Temperature
– Presence of male
• Most common reproductive problems during the postpartum
period include retained placenta, uterine /vaginal prolapse,
endometritis/pyometra, different forms of postpartum
complications (injuries and metabolic)
• 1. Retained Placenta (RP)
• A cow normally expels her afterbirth (placenta) within 2-6 hours
after parturition. A placenta which has not been passed by 12
hours is considered a retained placenta. If the cow shows no
signs of illness (e.g., fever, off feed) there is little cause for
alarm.
• Most cows will expel a retained placenta within 6-8 days after
calving. Manual removal should be avoided to prevent excessive
haemorrhage in the uterus or introducing additional infection
into the uterus.
• The placenta is best left alone or simply cut off where it hangs out of
the vulva. It is not recommended that uterine boluses be put into the
uterus routinely as this may result in a delay of the decomposition of
the placenta and, therefore, prolong its passage.
• If an animal with a retained placenta loses her appetite or
seems dull and lethargic, it may have an elevated temperature;
antibiotic should be given daily until her appetite is normal.
Incidence of RP in dairy herds should not normally exceed 8%
• Possible factors involved
– Non specific and specific infections such as Brucella, leptospira,
campylobacter, IBR and others can result in RP. These infections
can cause abortion but can also cause RP following delivery at
term.
– Twin births and dystocia, including prolonged or CS are often
followed by RP
– Deficiencies of selenium, Vit A or E may cause higher than normal
incidence of RP
– Over-conditioning of dry cows due to excess energy intake and/or
prolonged dry period is often associated with RP
• Troubleshooting and control suggestions
• Test for specific infections. Use blood tests as well as bacterial or viral
cultures in diagnosing specific infections. If an infection is identified
treat, vaccinate or cull infected cows
• Minimize exposure to non-specific organisms by keeping calving areas
clean and well bedded. Calve on grass if practical. Do not use
maternity pens for other purposes
• Breed heifers to bulls with a record of calving ease. Provide assistance
if hard labor continues for over 30 minutes with out progress.
• Provide supplemental Se as dry feed or injection in deficient areas.
Provide cows with fresh forage as pasture or green chop for at least 4
- 5 weeks each year. Provide Vitamin A (1mg of carotene = 400 units
of Vit A)

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• Prolapse of Vagina and Uterus
• Inversion of the Vagina and/or Uterus from vulva. Slight vaginal prolapse not
uncommon late in gestation in many animals usually older cows and ewes
caused by excessive relaxation of pelvic ligament by relaxin. vaginal prolapse
is not a serious problem
• Uterine prolapse occurs shortly after parturition. This is a true emergency
or an acute condition often associated with hypocalcemia and may also
follow use of great force in fetal extraction.
– It is not hereditary.
– It is more frequent in cows and ewes than sows and mares often
associated with dystocia or retained placenta.
• Excessive straining during parturition, ingestion of estrogenic feeds such as
red clover leads to prolapse. The prolapse can involve other organs such as
the bladder or intestines. In some cases, the uterine artery may rupture with
fatal consequences.
• The prognosis is relatively good if the uterus does not suffer too much
trauma and is replaced properly. The chance of recurrence is little if properly
corrected, and there are no serious long term effects
4a826419f157b6bc1f66c8c80bef1bc1.mp4
Caslick's operation is used with
varying degrees of success.
pessaries are also used occasionally
with varying degrees of success

11/22/2023
19
• Metritis: Also called inflammation of the uterus, this disease
increases the calving-to-conception interval (by ∼18 d)
– Although minor uterine infections may clear up without any treatment, metritis
can be life-threatening
– Symptoms include fever, depressed appetite, lowered milk production and foul-
smelling uterine discharge. E. coli, staphylococci, Archanobacterium pyogenes
and mixed infections are generally implicated. Cows normally have red-to-brown
discharge during the first 2 weeks after calving. If the discharge persists beyond 2
weeks or if the discharge is foul smelling, this is evidence of metritis.
– Possible factors involved are: Many cows with RP will develop metritis,
injury to reproductive tract due to dytocia or during treatment,
contamination of the reproductive tract at calving and heifers are
susceptible (unhygienic conditions), use of uterine bolus can cause a
sterile pus condition due to body reaction to material contained in the
bolus, Se or Vitamin A deficiency can be associated with metritis, over
conditioning may predispose the cows to health problems such as RP,
Metritis, acetonemia and displaced abomasum at the time of calving
The Uterus
• Endometritis :
• Accumulation of fluid inside the uterine lumen are very
typical of females suffering from chronic endometritis
• Whenever fluid secretions are found in the uterus during
dioestrus they should be regarded as abnormal. Sometimes the
secretions are concentrated in a particular area of the uterus and
at other times they can be detected along the entire uterine
lumen
• The interface between the secretion and the surrounding uterine
wall is wavy
Transverse section through the uterine
horn (arrows) of a mare with chronic
endometritis
Uterus of a mare with large
accumulation of exudates as a
result of a chronic endometritis
Pyometra in mare. The uterus is
severely distended by a large amount
of fluid
Uterus and urinary bladder (arrow)
of showing severe endometritis

11/22/2023
20
Mucometra Urometra
• Pyometra – Pyometra is one form of metritis. This is a chronic
infection of the uterus. The animal usually has an accumulation
of fluid (pus) in the uterus and a corpus luteum on the ovaries
• The cervix could be open (Open pyometra) or closed (Closed
pyometra)
• Treatment involves the removal of the CL using PGF and
induction of uterine contraction with myotonic drugs.

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