Repro Lab Practical #1

What is the main structural difference observed in cow and mare ovaries? Explain.

Relative location of the cortex vs. the medulla:

* In cow, cortex is on outside and in mare cortex in on inside.
* Mare must ovulate through the ovulation fossa whereas cows can ovulate over the whole surface of the ovary.

How are boars housed at the Swine Educational Unit, and why are they managed this way?

Boars are housed **individually** or in **group** **pens**, depending on their **age** and **whether they display aggressive behavior** towards the other boars

A piece of gauze was placed on top of the collection cup prior to semen collection. What is the purpose of the gauze?

To collect the gel fraction of the ejaculate/prevents the gel fraction from entering the semen collection cup

At what age will the NCSU Swine Educational Unit start to use a boar’s semen for breeding?

When the boar is 8 months of age

Which type of gloves were preferred during semen collection in boars? Why that type?

Vinyl gloves - reduce the chance of killing sperm cells

What prevents boars from being collected using an artificial vagina?

To ejaculate, boars require pressure in addition to the proper temperature. The amount of pressure on the boars glans penis can not be achieved with an artificial vagina, thus we collect via a gloved hand.

Identify the following acronyms:

a. GnRH

b. LH

c. E2

d. P4

e. PGF2a

a. Gonadotropin Releasing Hormone

b. Luteinizing Hormone

c. Estrogen or Estradiol

d. Progesterone

e. Prostaglandin F2alpha

Provide the Brand Name of the hormone or chemical you would use in the following scenario:

Inducing puberty in prepubertal gilts

PG-600 or Matrix

Provide the Brand Name of the hormone or chemical you would use in the following scenario:

Superovulating embryo transfer donors in cattle

FSH-P, Super-OV, FollitropinV

Provide the Brand Name of the hormone or chemical you would use in the following scenario:

Controlling out-of-season or early-season breeding in mares

Regumate

Provide the Brand Name of the hormone or chemical you would use in the following scenario:

inducing luteolysis regression in cattle

Lutalyse, Prostamate

Provide the Brand Name of the hormone or chemical you would use in the following scenario:

increasing intensity of uterine contractions during labor

Oxytocin, Pinocin

Provide the Brand Name of the hormone or chemical you would use in the following scenario:

treating ovarian cystic follicles in cattle

Cystorelin, Feragyl, Facteral

Provide the Brand Name of the hormone or chemical you would use in the following scenario:

Blocking ovarian function in cattle

CIDR, MGA, Progesterone

Provide the Brand Name of the hormone or chemical you would use in the following scenario:

Increasing milk yield

Posilac

How would you interpret the results of weekly progesterone assays with following profile? (L=low, M=medium, H=high)

\
L-H-H

Ovulated approximately 14 days ago, retest in 7 days to determine pregnant or open

How would you interpret the results of weekly progesterone assays with following profile? (L=low, M=medium, H=high)

\
M-L-H

had subfunctional CL, it regressed & ovulated in past 7 days

How would you interpret the results of weekly progesterone assays with following profile? (L=low, M=medium, H=high)

\
L-L-L

Anestrous, non-functioning ovary, not ovulating

How would you interpret the results of weekly progesterone assays with following profile? (L=low, M=medium, H=high)

\
H-H-H

Anestrous, but pregnant

How would you interpret the results of weekly progesterone assays with following profile? (L=low, M=medium, H=high)

\
L-M-L

Ovulated, but had a subfunctional CL and it regressed

How would you interpret the results of weekly progesterone assays with following profile? (L=low, M=medium, H=high)

\
L-L-H

Recently ovulated in past 7 days

What other body fluids could be used for monitoring hormones?

Milk, Urine, Salvia, CNS fluid, Feces, Blood, Sweat

What are the advantages of using this type of kit to determine when to breed your cows?

Determine cyclic animals, Identify short cycles, better management of animals estrous cycle

What are the disadvantages of using this type of kit to determine when to breed your cows?

Cost, Time, inconsistent testing, may claim an animal is pregnant when she is not (false positives)

Draw a graph that illustrates the bovine estrous cycle. Make sure you include the following hormones: progesterone, estrogen, and PGF2α.

What are the two exogenous reproductive hormones used in the NC Synch protocol.

* Gonadotropin Releasing Hormone (Factrel)


* Prostaglandin F2a (Lutalyse)

What is the length of the goat estrous cycle, and when do these animals generally display estrus?

Estrous Cycle Length – 21 days

Seasonal Breeders – display estrus in Fall

What are two signs/symptoms that a doe is in estrus?

* Interest in buck
* Raised tail
* Vocalizations
* Red/swollen vulva
* Sometimes mucus from the vagina is present

What is the site of semen deposition by AI and natural service in the doe?

AI – Uterine Body

Natural Service - Vagina

What are the advantages of using artificial insemination in small ruminants?

\
* Introduce new genetics
* Introduce new breeds
* Small herd and don’t want to mess with a buck

What are the disadvantages of using artificial insemination in small ruminants?

* Requires more labor
* More invasive
* Requires more equipment

What is the flushing effect?

Increase the amount of feed prior to breeding, mostly increasing energy, about 1 month before introducing bucks.

* Hope to increase body weight, ovulation rate, and therefore litter size

What are the restrictions in place when using the flush effect? When will it work/not work?

* Must continue through breeding season and for 30-40 more days.
* Doesn’t work in does that are too fat (BCS 4-5) or too thin (BCS 2 or less)

What is the “buck effect”?

Strategic exposure of does to intact males will result in the doe displaying estrus approximately 7 to 10 days after the introduction of the buck.

What are the restrictions in place when using the buck effect? Where does the buck need to be?

* Bucks need to be isolated from does for this procedure to be effective.
* Buck must be out of the doe’s line of sight and sense of smell for an extended period of time, perhaps as long as several months

What is the purpose of conducting a breeding soundness exam (BSE) on bulls?

The purpose is to identify bulls that are capable of breeding and to identify individuals that may be injured and unable to breed females.

How often should a BSE exam be done?

A BSE should be conducted 30 to 60 days before very breeding season.

What is the main purpose of collecting heifer pelvic measurements?

Screening tool to identify heifers likely to have calving difficulties

What is the minimum scrotal circumstance size a yearling bull must have to pass its breeding soundness exam at the Beef Educational Unit?

32 cm

Name at least 1 factor that a breeding soundness exam in bulls doesn’t test for.

Libidio

What is the name of the tool used to take heifer pelvic measurements?

Pelvimeter

What is a good male-to-female ratio for the average bull?

For young bulls a ratio of 1 bull to 12 females.

For mature bulls a ratio of 1 bull to 36 females

Number of females should equal the number of months old the bull is.

Assuming they are in good health and pass the BSE

How do you calculate the measurement for the total heifer pelvic area?

Multiply the measurement for the height by the width measurement, this gives the square area (cm^2)

When is the best time to take hiefer pelvic measurements? What is the minimum pelvic measurement that is recommended?

It is recommended to do this 4-6 weeks before breeding season. No less than 140 cm^2

Should heifer pelvic measurements be used as a screening tool or a selection tool?

A screening tool - If you use it as a selection tool you will simply be picking your larger framed animals. Ideally, you should identify the animals with abnormally small pelvic measurements and cull them.

Describe the the estrous scale used at the Equine Educational Unit. Be sure to inclde what each number represents

0 = Violent Behavior

1 = Indifferent Behavior

2 = Slightly Interested

3 = Interested, Winking, may urinate

4 = Greatly interested, Urinating, Squatting, and will lean into stallion

How often should you tease mares to determine when they are ready to breed?

Everyday or every other day

Mares are classified as what type of breeders and when do they display estrus?

Long day breeder, only display estrus when daylight is increasing

How many progressively motile sperm should be in an on the farm breeding dose?

500 Million

How many progressively motile sperm should be in a shipping dose?

1 Billion

Name 2 things that we look for in a semen evaluation.

Color and Volume of the ejaculate

Sperm Concentration

Sperm Motility

Sperm Viability

Sperm Morphology

What kills sperm?

Everything kills sperm

What type of artifical vagina is used at the Equine Educational Unit and why is this type prefered?

Used to use the Colorado as it maintains temperature and pressure better; have now switched to the Missouri as it is **lighter**

Free teasing

Stallion comes up to fence, mares are loose OR stallion in a small pen, mares are loose in pasture around him

In hand teasing

Stallion comes up to fence, mares are walked up individually

Stall Teasing

stallion walked up down barn aisle, mares are in stalls

Cystorelin, Fertagyl, Factrel Hormone + Structure

GnRH (peptide)

Cystorelin, Fertagyl, Factrel Use

Treatment of Cystic Ovaries, stimulate LH and FSH

Cystorelin, Fertagyl, Factrel Species

Cattle (dairy)

Oxytocin Use

Stimulates Milk letdown, Stimulates uterine contractions

Oxytocin Species

ALL - Cattle, Horses, Swine, Sheep, Dogs

Lutalyse, Prostamate Hormone/Structure

Prostaglandins (PGF2a)

Lutalyse, Prostamate Use

Regress CL to control the onset of estrus, induce parturition

Lutalyse, Prostamate Species

Cattle, Horses, Swine

pLH Hormone/Structure

Gonadotropins (LH) - protein

pLH use

Induction of ovulation

pLH Species

ALL

Follutein, Pregnyl Hormone/Structure

Gonadotropins (hCG) - protein

Follutein, Pregnyl Use

Treatment of Cystic Ovaries, Induce ovulation

Follutein, Pregnyl Species

Cattle

FSH-p, Folltropin-V, Super-OV Hormone/Structure

Gonadotropins (FSH) - protein

FSH-p, Folltropin-V, Super-OV Use

Superovulation of embryo donors

FSH-p, Folltropin-V, Super-OV Species

Cattle, Horses, Swine, Sheep, Dogs

Gestyl Hormone/Structure

Gonadotropins (PMSG) - protein

Gestyl Use

Superovulation, stimulatation of estrus during anestrous

Gestyl Species

Cattle

P.G. 600 Hormone/Structure

Gonadotropins (PMSG+hCG) - protein

P.G. 600 Use

Induction of estrus in anestrous gilts and sows

P.G. 600 Species

Swine

Posilac Hormone/Structure

Somatotropin (bGH or bST) - protein

Posilac Use

Increase milk production

Posilac Species

Cattle

Regumate Hormone/Structure

Progestogens (Progesterone) - steroid

Regumate Use

Synchronize estrus in mares or cyclic pigs, suppress foal heat

Regumate Species

Swine, horses

Melengesterol Acetate Hormone/Structure

Progestogens (Progesterone) - steroid

Melengesterol Acetate Use

Suppress or Synchronize heat

Melengesterol Acetate Species

Cattle

Megestrol Acetate (Ovaban) Hormone/Structure

Progestogens (Progesterone) - steroid

Megestrol Acetate (Ovaban) Use

Prevention of estrus

Megestrol Acetate (Ovaban) Species

Dogs, Cats

Depo-Provera Hormone/Structure

Progestogens (Progesterone) - steroid

Depo-Provera Use

Prevention of estrus

Depo-Provera Species

Dogs, cats

Fluorogesterone Acetate Sponges Hormone/Structure

Progestogens (Progesterone) - steroid

Fluorogesterone Acetate Sponges Use

Synchronize estrus

Fluorogesterone Acetate Sponges Species

sheep/goats

CIDR Hormone/Structure

Progestogens (Progesterone) - steroid

CIDR Use

Synchronize estrus