Myth Regarding Artificial Insemination and correct procedure
Dr. SANJAY K. MISHRA
Veterinary Medical Officer, Animal Husbandry Department U.P.
Ex-Assistant professor, Gynaecology and obstetrics, C.V.Sc. & A.H., DUVASU, Mathura, U.P. India
*Myth regarding Artificial Insemination and correct procedure*
Dr. SANJAY K. MISHRA
Veterinary Medical Officer, Animal Husbandry Department U.P.
Ex-Assistant professor, Gynaecology and obstetrics, C.V.Sc. & A.H., DUVASU, Mathura, U.P. India
1. *Myth:*
Transfer of semen is not time dependent.
• *Correct Procedure:*
Make all semen transfers between nitrogen tanks or retrieval of semen from a nitrogen tank within 5 seconds or within 10 seconds if extreme heat or high winds are present. This time range will keep sperm within a safe temperature range.
2. *Myth:*
Thawing procedures are not critical as long as semen is thawed.
• *Correct Procedure:*
Thaw semen in 95 to 98°F (35 to 37°C) water for 40 seconds. Fertility comparisons show an advantage for semen thawed in warm water.
3. *Myth:*
Shaking the straw to move all semen away from the end of the straw that is going to be cut damages sperm cells.
• *Correct Procedure:*
Move the air bubble to the laboratory seal end of the straw before cutting. This will not damage sperm, and if the semen is not moved away from the end that is to be cut, 1 to 5% of the sperm will be lost.
4. *Myth:*
Changes in temperature after semen has been thawed are not important.
• *Correct Procedure:*
Protect semen from environmental changes while loading into insemination gun/equipment and transferring to the cow at proper place and correct time of oestrous. Failure to protect sperm can either cause cold shock or heat stress, both of which will result in lowered fertility.
5. *Myth:*
Fertility of thawed semen is not dependent on insemination time.
• *Correct Procedure:*
Inseminate semen as soon as possible after warm water thawing, but within 15 minutes. Higher fertility can be obtained by thawing semen in warm water (See Correct Procedure @ 2) if the semen is placed quickly into the reproductive tract of the cow. Sperm deteriorate rapidly outside of
the reproductive tract and by 15 minutes after thawing the advantage of warm water thawing has been lost.
6. *Myth:*
Semen stored under liquid nitrogen is better than semen stored in liquid nitrogen vapors.
• *Correct Procedure:*
An on-farm semen nitrogen tank must contain liquid nitrogen, but the level of nitrogen is not important. Today the on-farm semen nitrogen tank is so well insulated that the differences in temperature between semen stored directly in liquid nitrogen and semen stored in vapor at the top of tank is only a few degrees. No difference in semen quality can be detected at these storage conditions.
7. *Myth:*
Semen stored in plastic goblet on racks has higher seminal quality.
• *Correct Procedure:*
Use of either a plastic goblet or the ABS metal rack will provide adequate protection during storage and handling because semen in either rack system has a good margin of safety when transferred within 10 seconds (See Correct Procedure @1). The metal rack does have advantages over the goblet rack type.
8. *Myth:*
Never thaw more than 2 units of semen at one time.
• *Correct Procedure:*
Thaw only the number of units of semen that can be placed in the reproductive tract within 15 minutes. The advantage of warm water thawing exists for up to 15 minutes (See Correct Procedure @5). The actual limit is not the number of units of semen to thaw, but instead the capability of the inseminator as well as the impacts of the facility. Early reports had shown a dramatic decrease in conception when thawing more than 2 units of semen at a time. Upon further review, this early study lacked enough
numbers to obtain useful statistical information and may have been impacted by ambient temperature/humidity. More recent work with over 14,000 inseminations on multiple sites has shown no statistical difference if semen is placed in the reproductive tract within 15 minutes.
9. *Myth:*
Switching to unproven or less expensive semen on “problem breeders” is justified after 3 services.
• *Correct Procedure:*
Continue to breed animals with proven A.I. sires until the animal is added to the cull list. The chances of an animal becoming pregnant is approximately the same after many services, excluding a small percent of cows with “pathological problem ” or long lactation stale cows. This consistent fertility can be seen in herds where many inseminations are available and no bias is introduced on whether to breed an animal in heat or what type of semen is used in breeding. In reality, most “problematic cows” are the result of not getting semen into a cow consistently in the first half of lactation or breeding decision bias described
previously. In addition, Progeny Test sires (young sires) have no fertility information available and as a group, have no fertility advantage over proven sires.
