Semen Collection and Handling Techniques

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Questions and Answers

What temperature should the glass collecting tube be to avoid cold shock during semen collection?

37°C

What is the maximum dilution ratio for semen that scores 5 in both motility and concentration?

4:1

Why should semens scoring 2 not be diluted?

It should be used fresh and undiluted.

What method is commonly used to synchronize the estrus of ewes?

Use of a teaser ram or testosterone-treated wether. Signup and view all the answers

What is the typical dilution ratio for most ejaculates?

2:1 Signup and view all the answers

At what temperature should both the semen and diluent be when performing dilution?

30°C Signup and view all the answers

What is a significant difference in semen handling between buck and ram semen?

Buck semen is less concentrated, requiring a lower dilution ratio. Signup and view all the answers

What are the two pharmacologic procedures commonly used for estrus synchronization?

Progesterone and prostaglandin therapy. Signup and view all the answers

What is the primary purpose of using a minimum-contamination technique during insemination in mares?

To minimize the risk of introducing pathogens and ensure a higher success rate of conception. Signup and view all the answers

What is the typical range of spermatozoa count that mares should be inseminated with?

Mares should be inseminated with 250 × 10^6 to 500 × 10^6 progressively motile spermatozoa. Signup and view all the answers

When is the best time to inseminate mares to achieve maximum pregnancy rates?

Mares should ideally be inseminated within 12 to 24 hours prior to ovulation. Signup and view all the answers

Describe the procedure for collecting semen from a ram using the electro-ejaculation method.

A bipolar electrical probe is inserted into the ram's rectum and low voltage stimulation is applied until ejaculation occurs. Signup and view all the answers

Why is the artificial vagina (AV) considered the preferred method for collecting ram semen?

The AV is less stressful for the ram and typically yields more consistent sperm quality and quantity. Signup and view all the answers

What is the purpose of the insulated jacket used in the artificial vagina (AV)?

The insulated jacket maintains the entire AV at approximately 45°C during the collection process. Signup and view all the answers

What is the recommended temperature range for lubricating the interlining of an artificial vagina?

The recommended temperature range is between 42 and 46°C. Signup and view all the answers

What factors can affect the success of electro-ejaculation in rams?

Variation in sperm concentrations, volume, and potential contamination with urine can affect electro-ejaculation success. Signup and view all the answers

How is the bull stimulated prior to ejaculation in the AV?

The bull undergoes precollection stimulation with 3 to 5 false mounts and active restraint before being allowed to mount a teaser animal. Signup and view all the answers

What is the typical volume range for mare inseminate?

The volume of the inseminate typically ranges from 5 to 20 mL. Signup and view all the answers

Describe the electro-ejaculation method and its intended use.

Electro-ejaculation involves stimulating the nerves supplying the reproductive organs using a probe or finger electrodes, typically used for lame or old bulls. Signup and view all the answers

What is the usual volume and sperm concentration found in a bull's ejaculate via electro-ejaculation?

A bull typically ejaculates 7 to 10 mL of semen containing 1.0 to 1.5 billion sperm/mL. Signup and view all the answers

What is the recommended method for thawing frozen semen straws?

Thawing 2 or 3 mL straws should be done in a 37°C water bath for 45 seconds. Signup and view all the answers

What precautions should an inseminator take when handling thawed semen on cold days?

The inseminator should protect the thawed semen from cooling down or refreezing and maintain a 37°C temperature while loading the insemination gun. Signup and view all the answers

Why is it important to prewarm the insemination gun before use?

Prewarming the gun helps to prevent the thawed semen from cooling down during loading, which can compromise sperm viability. Signup and view all the answers

What happens immediately after a bull ejaculates into the artificial vagina?

After ejaculation, the AV is tilted downward to allow the semen to drain into the collection test tube. Signup and view all the answers

What is the purpose of the filter in the artificial vagina during semen collection?

The filter allows the sperm-rich portion of an ejaculate to pass into the receptacle while retaining the gel fraction. Signup and view all the answers

What temperature range should the internal temperature of the artificial vagina not exceed during semen collection?

The internal temperature should not exceed 45 to 48°C. Signup and view all the answers

How can the temperature of the water jacket be adjusted without injuring spermatozoa?

The temperature of the water jacket can be adjusted to 50 to 60°C when the glans penis is beyond it. Signup and view all the answers

What type of lubricants should be used inside the artificial vagina?

Only nonspermicidal lubricants should be used. Signup and view all the answers

What is the recommended semen to extender ratio for semen that will be used shortly after collection?

The recommended ratio is 1:1 to 1:3 of semen to extender. Signup and view all the answers

What is the optimal temperature range for transporting semen to the laboratory?

Semen should be transported maintaining a temperature of 35 to 37°C. Signup and view all the answers

Why is it important to clean and dry the stallion's penis before collecting semen?

Cleansing and drying reduce contamination risk and prepare the penis for effective collection. Signup and view all the answers

What type of equipment should be used for artificial insemination procedures?

Only sterile, nontoxic, disposable equipment should be used. Signup and view all the answers

What is the significance of using Dorset rams as teasers compared to Romney rams?

Dorset rams resulted in a higher breeding rate of 67% in ewes during the first two weeks, while Romney rams had a breeding rate of only 34%. Signup and view all the answers

How long should ewes be isolated from rams before introducing teaser rams for effective stimulation?

Ewes should be completely isolated from rams for approximately two months. Signup and view all the answers

What are the four methods of artificially inseminating ewes?

The four methods are vaginal artificial insemination (VAI), cervical artificial insemination (CAI), transcervical artificial insemination (TAI), and laparoscopic artificial insemination (LAI). Signup and view all the answers

What hormone secretion occurs within 10 minutes after introducing a stimulating ram or pheromones?

Ewes begin to secrete gonadotrophins. Signup and view all the answers

What role do wethers treated with testosterone propionate play in stimulating ewes?

Wethers treated with testosterone propionate are nearly as effective at stimulating ewes as rams. Signup and view all the answers

Why is it advisable to keep intact rams in an adjacent field rather than in direct contact with ewes?

Keeping intact rams nearby prevents ewes from mating if they go into behavioral estrus during the teasing period. Signup and view all the answers

What is the recommended ratio of teaser rams to ewes for effective stimulation?

A ratio of one teaser ram per 100 ewes is normally required. Signup and view all the answers

How effective is a two-day exposure to rams compared to a 17-day teasing period?

Two days of exposure to rams is as effective as teasing for 17 days. Signup and view all the answers

When should a single insemination occur after removing the progesterone pessary if using PMSG?

54 to 56 hours after pessary removal. Signup and view all the answers

What is the recommended timing for inseminating ewe lambs after removing the pessary?

50 hours after pessary removal. Signup and view all the answers

What is the insemination time range when using CIDR without PMSG for synchronization?

48 to 57 hours after removal. Signup and view all the answers

How does double insemination affect conception rates and prolificacy?

It typically results in a 5 to 10% increase in conception rates and enhances prolificacy. Signup and view all the answers

What is the suggested insemination timing for superovulated ewes with PMSG or FSH?

Insemination should take place earlier than usual after pessary withdrawal. Signup and view all the answers

When using frozen-thawed semen, when should insemination occur after pessary withdrawal?

44 to 48 hours after pessary withdrawal. Signup and view all the answers

What is the recommended insemination interval for the LAI method after CIDR withdrawal?

48 to 52 hours after CIDR is withdrawn. Signup and view all the answers

For fresh semen use in insemination, what is the preferred interval after removing the pessary?

Insemination is performed 36 to 48 hours after withdrawing the pessary. Signup and view all the answers

Study Notes

Artificial Insemination

Artificial insemination (AI) is a vital technique for genetic improvement, allowing a limited number of superior males to inseminate many females.
AI is superior to embryo transfer in its ability to use many high-quality males for breeding.
Early documentation of AI dates back to 1780, with significant advancements in the 20th century (Russia and Japan) and continuing development in the US and other countries.
Key advantages of AI include: enhanced genetic improvement, disease control, accurate breeding records, financial benefits, and safety (removal of hazardous males).
The procedure is enhanced with estrous synchronization programs that help control the timing of insemination.

Male Management/Semen Collection

Young males, appropriately managed and fed, provide semen effectively at specific ages.
- Bulls: 12 months
- Rams, goats, and boars: 7-8 months
- Stallions: 24 months.
Accurate semen collection is crucial for successful AI programs.
Techniques like live mounts (teaser females, other males, or castrated males) are the most effective for routine semen collection. Teaser animals are routinely used.
Semen collection methods must consider species-specific physiology and reproductive cycles.
Collection frequency needs to be controlled (especially with boars and young bulls) to avoid reducing fertility.

Mounts and Teasing Procedures

Using live mounts, like teaser animals, increases semen collection success.
Live mounts include teaser females, other males or castrated males.
Teaser animals are the most successful for standard semen collection.
Castrated males are also effective.

Artificial Vagina Preparation (Cattle)

Artificial Vaginas (AVs) are crucial tools for semen collection.
Water temperature control is critical; AVs are maintained near 45°C.
A proper AV is cylindrical rubber tubing, a thin rubber liner, thin-walled cone and a collection vial encased in an insulated jacket or case.
Lubrication inside the liner should be sterile.

Semen Collection (Cattle)

Collection frequency is twice daily for mature bulls (Monday, Wednesday, Friday) or twice weekly for young bulls (Tuesday, Thursday).
The average bull ejaculate contains 8 to 16 billion total sperm. A weekly target is 30 billion sperm cells. Additional approaches to stimulation for collection include changing locale or mount animals.
Stimulation techniques can require multiple approaches.

Artificial Insemination Techniques (Cattle)

The rectovaginal method is a standard approach in cattle.
Excess fecal matter removal from the area surrounding the vulva is crucial prior to AI.
The insemination gun is positioned at a 30° angle with the semen end uppermost to prevent sub-urethral or urethral penetration.
Slow semen deposition is key for even distribution.

Insemination Techniques (General)

The temperature of the inseminating device should be warmed.
A proper technique for placement is necessary (such as forward or downward motions).
Techniques vary by species and specific animal.
Recording details aids reproducibility and management of procedures.

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Description

Test your knowledge on the best practices for semen collection and handling in livestock, particularly focusing on ewes and mares. This quiz covers topics such as temperature control, dilution ratios, and estrus synchronization methods. Improve your understanding of artificial insemination techniques and procedures commonly used in veterinary practices.