Best Practice for Frozen Semen Handling

Published on Wed, 07/17/2019 - 4:20pm

 Best Practice for Frozen Semen Handling.

 By Michael Cox.

 Using artificial insemination straws as part of a herd’s breeding program is a wonderful way of rapidly improving the quality and genetic merit of the herd. But the benefits of A.I. can only be achieved if the straws themselves are correctly stored and handled. American Dairymen Magazine recently caught up with Amanda Engle, independent sales and A.I. tech with Select Sires, based out of Hamilton, Alabama, to learn more about frozen semen handling.

A.I. Tank
Tank management is often the best place to start when evaluating A.I. straw management. The tank should be located in a safe, secure area where there is no risk of it getting knocked over or damaged from falling objects. Placing a sheet of cardboard or mat under the tank can help give it a secure base. Best practice recommends not using a second-hand tank as there is a possibility it may leak nitrogen gas and potentially kill all the semen held in a faulty tank. “If you do choose to go with a second-hand tank,” Engle says, “be sure to fill it with nitrogen in advance of putting straws in there and test the nitrogen level again after three months for leaks.”

Managing the environment
While straws will be held safely in a properly functioning tank, there is a risk that damage can occur to straws when the tank is opened for adding more straws or taking straws out for breeding. “I like to be strict on the time limit here of having straws exposed to the outside air,” Engle says, “less than 20 seconds should be enough time to grab what straws you need and get the rest back down into the chamber safely.” Avoiding touching too many straws and keeping everything below the frost line as much as possible will help protect straws from a sudden change in environmental temperature. Using a tweezers to pull up straws will reduce their exposure to the warm hands and fingers of the AI tech. “The surface area of straws is really high, so the actual volume of semen is easily exposed to the elements once it’s pulled up from the chamber” Engle says.
Once the correct straws have been identified and pulled out, they should be immediately transferred into the thaw bath. After thawing, the straw should be carefully dried with a paper towel, the tip cut off at a perpendicular angle with a sharp scissors, loaded into the sheath and then loaded into the AI gun. From this point until insemination, there is a window of 15 minutes in which to inseminate the cow. If a barn or room facility is unavailable for working with straws, preparing the straws inside a vehicle is the next best option. The main point to consider is protecting the straws from wind-chills during cold weather and excess heat during summer months. “Taking straws out of the bath feels the same as us stepping out of a shower – the air temperature can shock the semen if it’s very cold or hot,” Engle says.

Patience and practice
To help the entire process run smoothly, the cows should be loaded into the chute and ready for insemination before the straws are thawed. If a large number of cows are to be bred, a second trained person should be in charge of thawing straws and loading guns. While time is of the essence for most steps in straw handling, Engle says techs should relax more once the gun is inserted into the cow. “When the gun is in the cow, we don’t need to rush anymore. The semen isn’t in any danger of being damaged once it’s inside the cow, so we can take as much time as we need now and make sure the semen is deposited correctly.” Engle, who facilitates several Select Sires A.I. training schools every year, believes that feeling rushed is one of the most common mistakes new A.I. techs face when they begin breeding cows. “When a cow doesn’t conceive to A.I., we never know exactly when or where something went wrong, so patience and practice are very important to help us get as many cows pregnant as possible. Select Sires, like most other A.I. companies, go above and beyond the call of duty in terms of quality control, so everyone involved in handling straws on the ranch must follow the correct procedures to make the most of the top-quality genetics in the straws.” Engle also recommends gaining experience of handling, thawing and loading guns correctly by practicing at home with whatever cheapest straws are available to a new tech. “It’s all about learning the correct steps and practice, practice, practice.”