Lab #1 - Lambing

What is the length of a sheep pregnancy?

about 5 months, 144 to 152 days

Parturition

the act of giving birth

3 stages of parturition

preparation, expulsion of the fetus, expulsion of the fetal membrane (placenta)

Preparation Stage

activation of the lamb’s hypothalamic-pituitary-adrenal axis (HPAA) — the lamb releases a hormone that signals the end of pregnancy and the beginning of labor.

removal of the ewe’s progesterone block. the hormone progesterone produced but the corpus lute and the placenta had been preventing dilation of the cervix and contraction of the uterus. Once the ewe’s progesterone starts to decrease, her cervix can dilate and the uterus can contract

stage 1 ends when the water breaks. (water breakage describes the rupture of the membrane or sac that surrounded the lamb during pregnancy. The sac contains fluid, so the term “water breakage” describes the observed release of the fluid)

Expulsion of the fetus

Uterine contractions & abdominal contractions move the lamb out into the world!

Expulsion of the fetal membranes (also called the placenta)

Fetal membranes may be expelled with the lamb or shortly afterward

If the fetal membranes are not expelled within 8 to 12 hours, the membranes are considered “retained” and they serve as a potential source of infection for the ewe.

What are some signs of lambing?

• ewe isolating herself from others

• ewe with a water bag or fetal body parts presenting

• ewe that is straining or having abdominal contractions

• brand new baby, mom delivered quietly

• Constant standing & lying down

• Nickering

• Uncomfortable

Zoonotic Disease

Pathogens that can be transmitted from an animal to a human

PPE

Personal Protective Equipment such as goggles, mask, coveralls, boots, mask, & gloves

Which 3 lamb body parts should present at the vulva during delivery

• both front feet

• nose

• head

What is a normal length of delivery (stage 2)

30 minutes to 2 hours

what are 2 abnormal lamb presentations

• one bent front leg or one front leg one the top of the head —> abnormal but manageable

• Bad: just the head (legs are farther back, making it difficult to pass through the birthing canal), only the front feet are present, head is back (frequently lamb is deceased when in this position), only the tail is present

What MUST a lamb do immediately after birth in order to live?

Breathe - if there is fluid in its lungs, must be rubbed or patted to get the fluid out. If not, the amniotic membrane around them must be broken so they can breathe. Clear their nose and face too

Why is it critical o dip a newborn. lamb’s umbilicus (or navel) with antiseptic?

Decrease the risk of infection because the umbilical cord contains blood vessels, which can be an open pathway for bacteria to enter the bloodstream.

List 3 reasons it is critical for a lamb to stand and nurse within the first hour of life

1. Acquire fluid & energy

2. Maintain its body temperature

3. Receive antibodies in colostrum (passive transfer of immunity)

When is Lamb Processing performed?

1 to 3 days of age

Describe the correct location for placement of an ear tag in a lamb

The ear tag is placed in the middle of the ear, between either the 1st and 2nd area of cartilage, or the 2nd and 3rd area of cartilage

Define the 3-number system used on tags placed in the Left ears of lambs at the farm

• 1st number = last number of the year

• 2nd & 3rd = sex and birth order

What ear tag number will the 1st ram lamb receive in 2025?

501

What ear tag number will the 1st ewe lamb receive in 2025?

551

Why is it important to weigh lambs during processing

Allows us to compare the weights from birth and again later to calculate the rate of gain. Birthweight also allows us to asses health and make sure the lamb weighs a normal or appropriate amount to ensure it is healthy. We can also indirectly evaluate the mom’s milk production.

Why is tail docking performed?

To prevent fly strike - manure gets softer and can cling to their hind end, attracting flies to lay eggs and result in maggots. Illness and sores can result from these maggots.

3 methods of docking tails

• Elastrator band - placed about 3 joints down the tail

• Hot knife or Hot Docker - slowly cut through the tail at a very hot temperature

• Burdizzo - strong clamp that is held in place for 2 minutes to crush nerves & blood vessels, while a scalpel cuts off the tail below the clamp site

Why might a ewe’s diet be supplemented with Selenium and Vitamin E and/or lambs may receive an injection of Selenium and Vitamin E after birth?

The soil and forage are deficient in these. We supplement ewes with these to avoid white muscle disease which occurs with a deficiency of vitamin E and Selenium. These two aspects of a sheep’s diet aid with immune system, muscle and nerve function, and can lead to muscle degeneration without adequate amounts.