Handling Sexed Semen
Following the simple steps below will help to ensure the best possible success rates
- Identify the semen in your tank without raising the straw as this will lead to reduced quality
- Straws should always be handled with tweezers
- Avoid semen exposure. Keeps straws submerged well below the frost line of the storage tank.
- Do weekly checks of the storage tank, make sure your liquid nitrogen is topped up frequently.
- Minimise the length of time that a straw container is kept above the liquid nitrogen level while removing the straw to be used. Take no more than five seconds.
- Protect semen from environmental changes. Failure to protect sperm can result in lower fertility.
- Don’t load multiple straws.
- Heat detection should occur three times per day for at least 20 minutes each time
- Evening/Night heat detection is essential as a majority of activity occurs at this time.
- Use sexed semen on females with very high activity levels. Heat detection aids are very important e.g. Moocall, scratch patch.
- There should be at least two cycles (heats) observed prior to planned Ai at 18-24 day intervals on the chosen animal.
- Secondary signs of oestrus e.g. mounting, chin resting, vocalisation can be less reliable signs of heat. Less valuable semen (not sexed semen) can be used to service these animals.
The Service Period
- During this time, you should ensure stress free handling to get best results, with animals restrained so that they cannot move much when inseminating.
- For optimum results when using 4M, insemination should be carried out 12-18 hours after the onset of standing heat.
- Heat synchronisation programmes should only be used in conjunction with good heat detection. Sexed semen should not be used on Timed AI from fixed time AI programme.
- Milking cows – 4M sexed semen should only be used in younger (1st/2nd lactation) cows who are cycling normally and have not had a fertility damaging incident in that lactation. I.e. Twins, retained placenta, whites, cystic or treatment for Ketosis.
- The younger animals in your herd will have a higher fertility index and inherently more fertile.
- Only inseminate animals that have been identified in standing oestrus
- Deposit the semen in the body of the uterus. Do not attempt to deposit the semen at the tip of the horn.
- Check the temperature of the water in your electric thawing device with a thermometer
- Only remove one straw at a time for thawing.
- Flick the straw to remove and trapped nitrogen
- Thaw the straw straight away in an electric thawer at 37c for a minimum of 40 seconds
- Thoroughly dry the straw; water kills sperm
- Shake the straw to free trapped air bubbles. Use clean straw cutters or sharp scissors to cut off the sealed end
- Pre-warm the AI equipment and keep it insulated until the insemination.
- Protect from heat and cold shock post-thaw.
- Place the loaded insemination gun in a clean plastic glove. Then place it inside you clothing to transport to the cow.
- The thawer semen must be inseminated by a qualified insemination, within 5 minutes of removal from the tank.
- Do no split straws.