Taking Care When Handling Semen to Optimize Conception

  Mark Curry    (989) 984- 7027         Route Services and Sales
Sue Palen       (989) 277- 0480         Office Coordinator/ Products program
Greg Palen     (989) 277- 6031         “aAa” Breeding Guide / Certified Seed Specialist

Mich Livestock Service, Inc    “For the Best in Bulls”    “High Energy Forage Seed”
110 N Main St   (PO Box 661)   Ovid,  MI  48866                    phone (989) 834- 2661
email: greg@michiganlivestock.com             website:  www.michiganlivestock.com

 

Sending and receiving ”vapor phase” cryogenic shippers
Your farm tank is charged with liquid nitrogen, at a temperature of -320 degrees F.    Our truck inventory tanks are also liquid tanks, so when you buy semen it is at -320F temperature, and the general processor recommendation is that the canes should transfer from supply tank to your tank in less than ten seconds.    When dealing with 1/4cc straws (sexed or imported semen) the recommendation is less than eight seconds.     Here is where problems start:  the neck tube of your tank only has nitrogen vapor which rises to -140 degrees F.    As canes or straws come out of the neck, they rise above -140 degrees F, which is the minimum safe temperature for semen transport—thus the “less than ten” and “less than eight” second rules.

Most semen today is shipped via UPS or Federal Express in “Doble” or “vapor phase” shippers (DOT rules do not allow parcel carriers to handle “wet” nitrogen tanks).    Thus shipped semen is only at -140 degrees F during transport.    When we receive shippers here, we pour them full of liquid nitrogen before extracting semen, in order for protective liquid (-320F cold) to be in the straw cups when they move to our storage and transport.    Without this step, it is easy for the semen arriving via UPS to be damaged just removing it from the vapor shipper.    For most of us, if we order semen to be shipped direct to our farms (bypassing someone like us) you run the risk of damage in handling it from the shipper into your semen tank.    Again, the risk is greater if the semen (like gender selected) is packaged in the smaller diameter 1/4cc straws.

Pulling straws from your tank in order to breed cows
If you look in the neck of your semen tank, you will see there is a line of frost a couple inches down in.    This is the line above which canisters should not be pulled, it indicates how high the “safe” -140F temperature for stored semen is for your tank.    Using tweezers to extract straws inside the neck of the tank, preserves your remaining inventory at safe temps.    Pull a canister above the neck of the tank will progressively damage your semen, reducing conception rates.

Here is what happened to one of our suppliers
They sent semen on eight bulls to an independent AI service in Arkansas by UPS, in vapor tanks.   As cows began to be bred, conception rates were falling.    Retrieving the unused semen, we had it evaluated by Hawkeye Breeders’ lab in Iowa.     As part of the test, we separated straws out of TOP cups from straws in BOTTOM cups, same bulls.    Uniformly, the semen looked better from BOTTOM cups (which stayed in the body of the tank) but looked poorer from TOP cups.   It was easy to infer that these inseminators were poorly trained in semen handling and storage;  but it could also indicate that they had no nitrogen available to reliquefy the shipper before removing the canes when received.   

Avoid  overstocking  canes  in  your  own  tank
When it is time to breed a cow, you will go to your tank to pull out a straw of semen.    Again, as we think about the “ten second” (1/2cc) and “eight second” (1/4cc) rules, ask yourself how easy you (first)  find the  individual cane  with the chosen bull;  then (second)  extract a  single straw from that cane, returning the cane back down into the canister and the canister back down into the body of the tank.    If you hear a lot of sizzling when returning cane and canister, consider it may be taking you too long  to do this.     How much of that extra time is used up trying to find the right cane, pulling the cane away from other canes in the canister, and drawing out a straw from it?     Over time, you are creating the same damage to straws in the upper cups of canes that we could document from the semen testing experiment we did with Hawkeye Breeders.

It has become a strong suggestion from semen suppliers to avoid ordering in quantities other than 5 straw multiples, so that no one in the delivery chain has to separate straws out of a cup and transfer them into another cup.    This is part of the industry effort to maintain conception.

Avoid  thawing  multiple  straws  at  once  when  group  breeding
With straw technology it only takes 40 seconds to fully thaw a 1/2cc straw in 95 degree F water, less than 30 seconds to fully thaw a 1/4cc straw in 95 degree F water.    By contrast, if straws are left in thaw bath for longer than 15 minutes, the activated sperm cells begin to suffocate.   Now that so many Ov Synch “timed breeding” groups are done, especially in larger expansion herds, we see lower conception rates mostly related to expecting an inseminator to breed many cows at a time with no assistance in moving cows to chutes or loading AI guns before walking alleys.    Too many of them will thaw an entire cup or cane of straws at once.   Can they really get ten (or even five) cows accurately inseminated in less than 15 minutes??      

Try  to  locate  semen  tanks  and  AI  equipment  close  to  the  breeding  area
Having to carry a loaded breeding gun the length of a barn or free-stall pen in all but summer temperatures, can expose the thawed semen to “cold shock” which has been known for years to damage seasonal conception rates.    Live sperm cells expect to be at near body temperature.