ANSC 1000 Exam 3

-pull mares off 60 days before foaling; hay
-keep pastures short to prevent seed heads
-test pasture for fungus; reseed

What are ways to prevent fescue toxicosis?

KY31 (Kentucky 31)

What forage causes fescue toxicosis due to the presence of endophyte fungi?

The fungus is passed in the seed heads.

How is the fungus that causes fescue toxicosis passed from the forage to the animal?

Endophyte Fungus

\_________ \________ is present on KY31, which causes fescue toxicosis.

ergot alkaloid toxins

The endophyte fungi present on KY31 produces \________ \________ \_______, which causes fescue toxicosis.

dystocia, prolonged gestation, enlarged foals, thickened placenta, agalactia

What are symptoms of fescue toxicosis in mares?

agalactia, thickened placenta, aborted fetuses, poor appetite

What are symptoms of fescue toxicosis in cattle ("summer slump").

1. Animal must reach puberty
2. conceive
3. maintain pregnancy
4. undergo successful parturition
5. the offspring must survive
6. the uterus must undergo involution
7. the female must experience postpartum estrus and conceive again

For reproduction to be successful:
1.
2.
3.
4.
5.
6.
7.

1.Nutrition
2.Environment
3.Anatomical defects in reproductive tract
4.Endocrine system imbalance
5.Diseases

Factors affecting reproductive performance:
1.
2.
3.
4.
5.

dystocia; excess fat around reproductive tract

What reproductive issue is present in animals who are over-conditioned (fat)? Why?

Flushing

Increase level of nutrition ~30 days before breeding

The physiological mechanisms that are involved in reproduction no longer work; a female must carry a certain % of body fat to reproduce

What is a reproductive issue present with under-conditioned (thin) animals? Why?

Good;Thin

Which body condition (moderate, good, thin) showed the fastest post-partum estrus? Which one showed the least?

gaining

You must go into the calving season with cattle in the \_____ condition.

The 120 critical days are the calving season where you feed to gain weight, not to fatten.

What are the "120 critical days"?

weaning; calving

Cattle can lose weight between \____ and \____.

first calf

The nutrition program is especially important for \______ \_____ heifers.

1. Will be lactating for the first time
2. Still growing
3. Uterine involution

What are the 3 critical needs for extra nutrients in first-calf heifers?
1.
2.
3.

Uterine Involution

The process where the uterus returns to the way it was before pregnancy

Energy

\________ is the dietary component that is limiting.

1. Turkey 95%
2. Dairy Cattle 80-90%
3. Swine 80-85%

What are the top 3 industries that utilize artificial insemination?

-Maximum use of genetically superior sires
-Greater selection of affordable sires
-Use deceased sires
-Use incapacitated or dangerous sires
-Aid in reduction of diseases
-improve management

What are some of the advantages of AI?

-Increased labor, management, and facilities
-Accentuate poor genetics by using an inferior sire

What are 2 disadvantages of AI?

Lutalyse, Estrumate, and Synchromate-B

\__________, \_________, and \_________ are drugs used for the synchronization of estrus.

Artificial Vagina

Method of semen collection for bulls, rams, and stallions?

Gloved-Hand technique

Method of semen collection for boars?

Electroejaculator

Probe inserted into rectum that causes ejaculation through electrical stimulation

Decreases

If collected too frequently, the number of semen per ejaculate \______.

1.Volume
2.Sperm concentration
3.Motility of sperm
4.Abnormalities of sperm

After collection, semen is evaluated for:
1.
2.
3.
4

1-2 days

How long does fresh semen last?

indefinitely

How long can frozen semen last?

Extender

After collection, semen is mixed with an \_______ that dilutes it to a greater volume.

Capable of being fertilized 12-24 hours

What is the fertile life of the ovum?

-Sperm survive approximately 24 hours in female reproductive tract
-12 hours are required for capacitation
-Fertility is limited to last 12 hours
-Time for transport is

What is the fertile life of sperm?

1-2 days

Length of estrus in ewe?

1-3 days

Length of estrus in sow?

4-6 days

Length of estrus in mares?

16-20 hours

Length of estrus in cows?

~26 hours

How long after the beginning of estrus do ewes ovulate?

30-38hr

How long after the beginning of estrus do sows ovulate?

~30hr

How long after the beginning of estrus do cows ovulate?

24-48hr before end of estrus

How long after the beginning of estrus do mares ovulate?

12-18 hours after onset of estrus

When should you inseminate a ewe?

24 and 36 hours after onset of estrus

When should you inseminate a sow?

must palpate to determine follicle size

When should you inseminate a mare?

12 hours after onset of estrus

When should you inseminate a cow?

superovulation

Hormone treatment of female to induce multiple ovulations. Used for multiple births and embryo transfers.

1. decreased gestation length
2. decreased birth weights
3. increased calf loss at parturition and after
4. increased retained placenta

Cons of multiple births:
1.
2.
3.
4.

1. increased reproduction of valuable dams
2.decreased time for proof of dam through a greater number of progeny
3.extends reproductive life of dams who are old or injured
4.transport of exotic breeds or proven stock to underdeveloped areas

Pros of embryo transfer:
1.
2.
3.
4.

1.Costly
2.ET offspring are not necessarily genetically superior
3.success rate is variable and not guaranteed

Embryo transfer disadvantages:
1.
2.
3.

FSH

\______is commonly used to induce superovulation in cattle

Prostaglandins

are used to synchronize the estrous cycles of the donor cow and recipient cows

PGF2a

This drug is a prostaglandin that causes the regression of the corpus luteum

1.Selection-donors must be healthy animals of superior genetic makeup
2.Synchronization-donor and recipient must be in the same stage in their estrous cycle
3.Superovulation

3 Steps of embryo transfer
1.
2.
3.

1.Freezing embryos
2.Cloning and micromanipulation of embryos
3.Sexing embryos

3 Future paths of embryo transfer
1.
2.
3

Lactation

\_____ is a distinguishing feature of mammals.

1. provide nutrition to offspring
2. source of passive immunity to offspring

Mammary glands serve 2 functions:
1.
2.

dairy cows; goat; sheep

In the US, milk primarily comes from \______ and to a lesser extent \________ and \_______.

Mammary Glands

All mammals have \_______ \______.

Mammary Gland

This is a modified sweat gland that is regulated by hormonal control and used to nurture offspring

4 glands-4 teats

What is the udder structure of a cow?

4 glands-2 teats

What is the udder structure of a mare?

2 glands-2 teats

What is the udder structure of a ewe?

6-20 glands in two rows along abdominal wall

What is the udder structure for multiparous animals?

gland

A secreting organ

Exocrine gland

Gland that secretes fluid into a duct

Endocrine gland

Ductless glands that secrete hormones into bloodstream

1.Lactoferrin
2.Lysozyme
3.Immunoglobulins

3 antimicrobial proteins in milk:
1.
2.
3.

Lactoferrin

This antimicrobial protein found in milk binds to iron (Fe) required for bacterial growth.

Lysozyme

This antimicrobial protein found in milk is an enzyme that hydrolyzes bacterial cell walls.

proper intestinal flora

Factors in milk contribute to the establishment of \________ \_________ \______

1. Water
2. Lactose
3. Fat
4. Protein
5. Minerals
6. Vitamins

Composition of milk (specific names):
1.
2.
3.
4.
5.
6.

88% water and 12% solids

What % of milk is water? What % is solid?

Least-Holstein
Most- Jersey

Which dairy breeds have the least and most milk fat %?
Least-
Most-

mastitis

Inflammation of the udder

-dirty or poorly adjusted milking equipment
-poor milking practices (dirty animals)
-injuries to cows because of their surroundings

3 main causes of mastitis

California Mastitis Test

How is mastitis tested for?

Intramammary injections of antibiotics

How is mastitis treated?

Transfer of immunoglobulins, which can only be absorbed within the first 24 hours of the newborn

Why is colostrum so important, and why must it be given as soon as possible?

Mammogenesis

structural development or growth of mammary gland

Lactogenesis

associated with the end of pregnancy & parturition; tissues change from nonlactating to lactating state

Milk secretion

synthesis of milk by epithelial cells

Milk removal

passive removal from cisterns and ejection of milk from alveolar lumen

Lactation

milk secretion + milk removal

Galactopoesis

maintenance of lactation

Alveolus

Basic milk-producing structure in udder

myoepithelial

Epithelial cells are surrounded by contractile \________cells involved in milk ejection.

streak canal

Bottom opening of udder

1.Remove nutrients from the blood
2.Transform nutrients into milk
3.Discharge milk into the center of the alveolus
4. In the lumen of the Alveolus

Functions of epithelial cells:
1.
2.
3.
Where are they found?
4.

Around 500

\_______ of blood pass through udder to supply nutrients needed for 1 gal of milk

Teats and Skin

Sensory nerves of the udder are found in the \_____ and \____, instead of inside it, where there isn't much innervation.

intramammary pressure

Milk secretion is lowered & finally stopped by build-up of \___________ \________ caused by accumulation of newly-made milk

Growth hormone, adrenal corticosteroids, and prolactin

\_____________, \_____________, and \________ are responsible for initiation of lactation

the lumen of the alveoli

Prior to milking, milk is stored in milk cavity of the \__________

45

Milk letdown occurs after \___ seconds

Alveoli\----\>Gland Cistern \---\>Teat Cistern\----\>Streak Canal

List the path that milk travels through during milking or nursing.

Oxytocin

\_____________,hormone released by posterior pituitary, causes contractions of myoepithelial cells surrounding each alveolus, and forces milk into duct system and to cisterns.

Stimulation of teats or suckling reflex by calf which sends a neural signal to hypothalamus which signals pituitary gland to release oxytocin

How does milk letdown occur?

1.Negative pressure - such as with the milking machine
2.Positive pressure - such as with hand milking
3.Positive and negative pressure - both occur during suckling

The streak canal must be opened to remove milk. What are the 3 ways it can be opened?
1.
2.
3.

Epinephrine

\___________is released into blood and can override action of oxytocin during milk "hold up"