Semen Evaluation And Shipping

What are the three main methods of semen collection?

Artificial vagina, electroejaculation, and massage.

In canine semen collection, what must be ensured regarding the bulbourethral gland?

That it returns to normal size and the dog can retract the penis into the prepuce (simulates the “tie”).

What are common indications for semen evaluation?

Infertility, sexually transmitted diseases, sale, changes in sexual behavior, maturity, and breeding soundness.

What information should be included in a breeding history?

Age and breed, previous medical conditions, pedigree fertility, reproductive performance, Brucella titers, date of birth of last litter, number of offspring per litter, number of services per female, total females bred, libido, and mounting behavior.

What structures are examined during a semen-related physical exam?

Scrotum, testes, penis (including os penis), prepuce, pelvis, prostate, urethra, and rectum, along with a general PE.

What diagnostic tests may be included during semen evaluation?

Blood/serum chemistries, Brucella canis testing, CBC, chemistry profile, and urinalysis.

What environmental factors should be avoided when handling semen?

Temperature changes, exposure to water, exposure to disinfectants, and pH variations.

What temperature should equipment be warmed to for semen processing?

98.6°F (37°C).

What type of environment should semen be processed in?

A warm room.

What characteristics of semen can be readily determined during evaluation?

Volume, gross appearance, sperm motility, sperm concentration, live-to-dead ratio, morphology, and presence of foreign cells/material.

How is ejaculate volume measured?

With a volumetric flask (often part of the collection device).

What factors influence ejaculate volume?

Species, method of collection, repeated ejaculations (↓ volume), and arousal or teasing (↑ volume).

What are the three portions of the ejaculate?

Sperm-free watery portion, sperm-rich fraction, and sperm-poor fraction.

What are average ejaculate volumes by species?

• Boar: 250 mL
• Buck/Ram: 1 mL
• Bull: 5 mL
• Dog: 10 mL
• Stallion: 65 mL
• Tom: 0.04 mL

Does ejaculate volume correlate with fertility?

No.

What does opacity and color of semen indicate?

Sperm concentration.

Rank descriptive appearance from highest to lowest sperm concentration.

Thick/creamy opaque → Milky opaque → Opalescent milky → Watery white.

What contaminants may alter semen color?

Red blood cells (RBCs).

What is wave motion?

The swirling motion of sperm, observed subjectively at 40× magnification.

What are the four classifications of wave motion?

• Very good: Vigorous swirling
• Good: Moderate swirling
• Fair: Barely noticeable swirling
• Poor: No swirl but some motile sperm present

How does sperm concentration affect wave motion?

As concentration decreases, wave motion decreases.

At what magnification is progressive motility evaluated?

100× under a coverslip.

What are the classifications of progressive motility?

Very good (80–100%), Good (60–80%), Fair (40–60%), Poor (20–40%).

How is sperm concentration calculated?

Number of sperm observed × 2 million = sperm/mL.

What are average sperm concentrations (millions/mL) by species?

• Boar/Stallion: 150
• Buck/Ram: 3000
• Bull: 1200
• Dog: 300
• Tom: 1700

What stain is used to evaluate live vs. dead sperm?

Eosin–nigrosin vital stain.

How do live and dead sperm appear with eosin–nigrosin?

Live: White/clear
Dead: Pink

How many sperm are counted for the live–dead ratio?

200 sperm.

What stains are used for sperm morphology evaluation?

Wright’s stain or Romanowsky stain.

How many sperm are examined for morphological assessment?

100–500 sperm.

What are the two categories of abnormalities?

Primary and secondary defects.

Where do primary defects originate?

During sperm production.

Do primary defects affect fertility?

Yes — they are more serious and often affect motility.

What are examples of primary head defects?

Double heads; heads too large or too small; pear-shaped; round; twisted; knobby.

What are examples of primary midpiece defects?

Swollen, kinked, twisted, double midpieces, or midpieces attached eccentrically.

What is a primary tail defect?

Coiled tail.

When do secondary defects occur?

During storage in the epididymis or during smear preparation.

What are examples of secondary defects?

Heads without tails, protoplasmic droplets, bent tails, broken tails.

What cells should be minimal or absent in normal semen?

Leukocytes, erythrocytes, and epithelial cells.

Should bacteria or fungi be present in semen?

No.

What must be done prior to collecting a semen sample?

Clean the prepuce.

What type of formalin is used in pre-filled jars?

10% neutral buffered formalin.

What safety risks are associated with formalin?

Skin/lung irritation and carcinogenic risk.

What is the purpose of a specimen bag?

To contain the specimen and hold the submission form.

How should a formalin jar be packaged for transport?

Jar placed in a sealed specimen bag → then in a second bag with paperwork.

What is a slide holder used for?

Protecting and transporting prepared slides.

What must be done before placing slides into a holder?

Ensure slides are dry and properly labeled.

What is a culturette used for?

Transporting swabs for culture.

How should a culturette be prepared for submission?

Ensure the tube is securely closed and place it in a specimen bag with paperwork