Female Reproduction

Estrous Cycle

Estrous Cycle - Estrus

• Also known as heat• Period of time when the female is

receptive to the male• Hormone– Estrogen

Estrous Cycle - Metestrus

• Ovulation occurs• Hormone– LH• Leutinizing hormone

Estrous Cycle - Diestrus

• Assumes pregnancy• Hormone– Progesterone

Estrous Cycle - Proestrus

• If not pregnant the body prepares for estrus

Is the cycle working?

• How do we detect if an animal is heat? – Natural Signs– Heat detection aids

Natural Detection

• Timeline for heat– On a piece of paper you are going to

draw a timeline– Show the natural signs of heat

detection

Detection Aids

• Teaser Animals• Chin-ball markers• Heat pads• Tailhead Chalking• Recordkeeping• Pedometer

Teaser Animal

• Animal that has been made so that it cannot reproduce however it still has the hormones running through it’s body

• Can be done through surgery or hormone therapy– Females with added hormones• Androgenized

– Males surgery

Chin Ball Markers

Heat Pads

Tailhead Chalking

Record Keeping

Pedometer

Now What Happens?

• Mating– We will cover the different methods of

mating when we cover male reproduction

What happens now?

• Starts developing– 3 main stages• Ovum Period• Embryonic Period• Fetal Period

Ovum Period

• Fertilization– Union of sperm and egg– Takes place in the fallopian tube

• Cell Division – Cells undergo mitosis and begin to

divide

StagesZygote - 2 to 8 cells Morula – spherical mass

of cells

Blastula – mass of cellswith a hollow cavity

Embryo Stage

• Implantation– New embryo becomes implanted into

the uterine horn where it will be nourished and developed

– Abnormal• Ovarian: young seldom survive• Tubal: young occasionally survive to birth• Abdominal: young do not survive to full

term

Embryo Period

• Differentation – cells become organized into specific structures

• Completion of all major organ systems

• Looks like an organism

Fetal Period

• Placentation– Membranes develop to provide the

fetus with nutrition– Each embryo has their own set of

membranes • Twins have common membrane and

common blood supply– Freemartins

Placental Attachment

• Cotyledon– Contacts made at only certain points in

the uterus– Also known as buttons– Cows and ewes

Cow Ewe

Placental Attachment

• Diffuse– Contact is made over most of the

uterus– Mares and sows

Placental Structures

• Amnion– Inner most layer that forms the sac

(amniotic sac) • Filled with amniotic fluid that protects young

from shock and adhesion

• Umbilical Cord– Long flexible tube attached to the

placenta where food, oxygen, and wastes are exchanged between the mother and the baby

Growth and Development

• Fetus grows and organs continue to develop so that the animal can live on its own

How do I know if they are pregnant?

• Can choose to look if they are pregnant or wait

• Advantages and disadvantages• Different methods

Advantages of pregnancy Checking

• Early warning of breeding troubles• Rebreed non-pregnant females• Separate pregnant and non pregnant

animals• Provides a mean for culling• Increases profits– Can sell as pregnant animal– Slaughter animals bring more if they are known

open– Unproductive breeders can be culled

Disadvantages of Pregnancy Testing

• Health risk to the dam and fetus• Labor and equipment

Ways of Pregnancy Testing

• Rectal palpation– Primary method for all livestock– About 42 days after breeding

Ways of Pregnancy Testing

• Analysis of progesterone– Used in cattle, dairy, and sheep industry– Not really common although is

becoming more so– Check for levels of progesterone in

blood or milk– 30 days post breeding

Ways of Pregnancy Checking

• Ultrasound– Able to look and see the fetus– Must have a highly skilled technician– Depends on your technician when they

can detect

Ways to Pregnancy Test

• Ultrasonic– Listen for echoes

• Rectal doppler– Look for heart beat

Preparing for Birth

• Some producers do something called “flushing”– Giving the animal extra nutrients three

weeks prior to birth– Most animals (especially sheep) will

begin to look thinner because all nutrition is going into their babies

Preparing for Birth

• Animal will start to create an udder– As it gets closer most animals teats will

become waxy– Typically referred to as “bagging up”

Preparing for birth

• Bring the animal to a smaller area– Sheep = jugging– Swine = putting in farrowing crate– Cattle = bringing into smaller pens

• Allows the animals to be watched

Preparing for birth

• Sheep– Crutching • Removing the wool from the butt and

udder area

• Other animals are just left until they beginpaturition

How do I know when they are going to give birth?

• Cattle– Swollen udder– Fluid in udder changes from watery to thick,

milky colostrum– Muscles around tailhead shrink– Noticeable enlargement and swelling of the

vulva– Cow is nervous, uneasy, anorexic– Musclar contractions start– Look for young– Makes nest and wants to be isolated

How do I know when they are going to give birth?

• Sheep– 10 days prior, teats become full of milk– Vulva swollen– Cervical seal passes as thick creamy

mucus– Ewe becomes nervous

How do I know when they are going to give birth?

• Horses– 2-6 weeks udder swells– 7-10 days muscles shrink and abdomen

drops– 4-6 days prior teats fill with milk– 12-24 hours “waxing”

How do I know when they are going to give birth?

• Pigs– 3 days prior sow will spend most of the

time sleeping and eating– As it nears they will nest build– Clean and dry birth site– Vulva enlarges– Milk fills with teats 10-18 hours before

Parturition

• The act of giving birth• 4 Stages– Preparatory stage– Expulsion of fetus– Expulsion of the placenta– Period of rest

Preparatory Stage

• Restlessness of animal due to minor contractions

• Dilation of the cervix• Cervix expands allowing uterus and

vagina to become continuous canal

Expulsion of Fetus

• Increased contraction• Straining followed by a few minutes

of rest• Fetus in amnion is propelled through

the birth canal• Fetus exits the sac

Expulsion of Placenta

• Caused by uterine contractions• Should be expelled within 12 hours

following parturition– It may become retained and need to be

helped– Treat it with antibiotics

• Most animals will eat their placenta if you do not remove it from the pen

Period of Rest

• Mothering will kick in and they will begin to mother the animal– Clean and dry it off– Make sure that it gets up

• The mother will also rest

Proper Presentation

• Forelegs first with nose resting on the forlegs– Piglets can be born either way

• First water bag will appear on the outside increasing in size until it ruptures due to weight

Proper Presentation

• Immediately after the first bag a second bag will follow with the fetus inside

• If presentation is normal do not assist until necessary

Dystocia

• Difficulty giving birth• Problems– Oversized fetus– Multiple births– Breech presentation– Deviation in normal presentation– Failure to dilate– No contractions

Should I Lend Assistance

• Have some offspring been delivered already?

• Has anyone else attempted to assist? • Should I assist or call the vet?

Assistance Devices

PullingBy hand

OB Chains

MechanicalCalf Puller