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Copyright © 2015
Angus Journal

Consequences of Mishandling Frozen Semen

Accidental thermal exposure to frozen semen can cause fertility issues before breeding.

by Katy Kemp for Angus Journal®

STILLWATER, Okla. (Oct. 9, 2014) — From collection to insemination, Brad Stroud, Stroud Veterinary Embryo Service, said there are too many opportunities for accidental thermal exposure and decreased fertility to a straw of semen. Stroud presented at the 2014 Applied Reproductive Strategies in Beef Cattle (ARSBC) Symposium Oct. 8-9 in Stillwater, Okla., to explain proper semen-handling techniques.

Once semen leaves the quality control of a bull stud, too many chances for mishandling occur. With no organized curriculum for managing and handling cells and tissues in liquid nitrogen, Stroud said numerous handlers likely have no formal training or education on proper handling, and rely too much on “cowboy logic.”

It’s important to refrain from “cowboy logic” about semen handling. Believing a straw is still frozen and therefore viable is false reliability. Stroud’s data suggested any time the internal temperature of a straw went above –130° C, recrystallization occurs. The temperature of liquid nitrogen is –196° C.

Recrystallization multiplies for each accidental thermal exposure to a straw of semen, increasing the size of crystals within the straw, destroying the fertility of sperm cells. Stroud’s research also determined fertilization is likely depressed after more than 8 seconds of exposure.

Stroud demonstrated that even handling semen within the neck of a Dewar exposes straws to temperatures well above –130°. To avoid risk of decreased fertility, handlers should use a liquid nitrogen bath at all times, including when “breaking canes” and checking inventory.

“It only takes 10 seconds in the neck of a one-half-full Dewar to reach –100° Celsius internally, and –130° Celsius is the critical temperature,” said Stroud.

Education is the key to avoid mishandling frozen semen. To limit loss of fertility from improper handling, Stroud recommended The Guide to Handling Frozen Semen & Embryos, which can be found by visiting

Stroud spoke during Thursday’s ARSBC session focused on advanced reproductive technologies. Visit the Newsroom at to listen to his presentation and to view his PowerPoint slides and proceedings paper.

Comprehensive coverage of the symposium is available online at Compiled by the Angus Journal editorial team, the site is made possible through sponsorship by the Beef Reproduction Task Force.

Editor's Note: This article was written under contract or by staff of the Angus Journal. To request reprint permission and guidelines, contact Shauna Rose Hermel, editor, at 816-383-5270.