Get the basics right to avoid breeding complications

1 Ensure flask nitrogen levels are maintained

It is worth taking out a contract with an AI company to check flask nitrogen levels once a month

If nitrogen levels drop too low, there is an increased chance of semen defrosting and dying – if losses go unnoticed, it may be months before the problem is identified through poor pregnancy rates

Check the details of any contract carefully and make sure the contract is maintained – lack of insurance could be a big risk to your herd

2 Defrosting

Defrosting incorrectly will kill semen

Ensure defrosting water is at the correct temperature before removing straws from the flask

Automatic thawers are good, but check they are always at the right temperature (37C) and are not contaminated with dust

Check the correct thaw time with your semen provider

Keep a stopwatch by the water to ensure thaw time is correct

Pick the defrosted semen up with tweezers and dry off with a paper towel – your hands must not touch the straw directly as any chemicals on your hand could kill the semen – even through the AI glove.

3 Semen testing

When block calving herds are using semen from a previous season, it is worth while testing quality – quality is important for everyone, but even more so for block calvers as they only have one chance to get it right

At least 80-90% viable sperm is the acceptable sperm class, with anything below 60% not recommended for use

Semen can survive this long period, but it’s essential flasks are regularly topped up with nitrogen so that temperatures are maintained.

4 Label straws carefully

Every time you pull a straw out of the flask, you are killing a proportion of semen

Goblets should be colour coded with a chart on the wall or lid of the canister for easy identification.

Ideally, one goblet should contain one bull’s straws.

5 Minimise temperature variation to prevent semen losses

When selecting straws from the flask, straws must not be lifted above the frost line as any change in temperature can have a negative impact on sperm quality

Once a straw has been defrosted to 37C, it needs to be maintained at this temperature

The maximum time between defrosting and insemination is 20 minutes

Less experienced inseminators should defrost less straws to ensure semen is not exposed for too long

After defrosting: dry the straw with a paper towel – one drop of water reaching the end of the straw will kill semen; and warm the end under an arm, slide into the gun, cut a paper towel with the scissors to clean them, then cut the end of the straw, place the sheath over the end, tease the plunger up to check there is semen and then put the straw down your back to keep it warm.

6 Select bulls carefully

You should “buy semen, not be sold semen”

Use the DairyCo’s Breeding+ website to compare bulls and make an informed decision

Take the time to consider which bulls are right for your herd and ask the right questions

• Visit our website for a step-by-step guide to using breeding indexes

7 Training

Regular refresher training is beneficial to everyone, as is ensuring new inseminators are given the correct training

Poor technique can result in reduced pregnancy rates, which will impact on the bottom line and could also have negative implications in terms of cow welfare.

Comments from Rob Mintern, senior livestock consultant, Agrii; Vet Maarten Boers, The Livestock Partnership and breeding specialist; and Marco Winters of DairyCo.

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