Handling semen correctly is vital to prevent loss of quality

Correct semen handling is essential on any farm, but ensuring semen is of high quality is even more important for autumn block calving herds, says vet Maarten Boers, The Livestock Partnership.

“Block calvers only have one chance to get it right so it’s essential they maximise their chances,” he says.

When farmers are using leftover semen from the previous season it is worth testing its quality. “At least 80-90% viable sperm is the acceptable sperm class, with anything below 60% not recommended for use,” says Mr Boers.

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

Semen testing of AI straws can be carried out by the vet on farm and also by the semen company, but the key to maintaining semen quality is by correct handling, says Mr Boers.

“One of the main problem areas is drying straws after thawing. Straws must be dried with a paper towel after thawing – water is incredibly toxic to semen, just one droplet reaching the tip of the straw could create a serious risk.

The chances of deterioration in semen quality are also increases the more straws are handled, Mr Boers explains.

“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.

“Potentially, the unit could be lifted out of the flask more than 50 times before all straws are used and every time they are raised above the frost line, there could be serious consequences in terms of sperm viability.”

And a lack of clearly labelled goblets also increases the chance of semen exposure, according to Kingshay consultant and AI technician, Rob Mintern.

“When goblets are not clearly labelled, anybody selecting a straw will have to sort through the whole batch to find what they are looking for – potentially increasing risk of temperature change.

“Farmers should ensure goblets are colour coded with a chart on the wall or lid of the canister for easy identification.”

This is something agreed by Will Tulley, Tyndale Vets. “Farmers tend not to have good records of where straws are in the flask. Ideally one goblet should contain one bull’s straws.”

AI routine after the straw has been removed from the canister must also be correct to minimise risk of deterioration in semen quality, says Mr Mintern.

“Thaw times and water temperature vary, but as an example, a 0.25cc straw may need to be thawed at 37C water for 14 seconds.

“In this case, you have 14 seconds to pick up the towel, warm the gun and put the rod down your back so it stays warm.”

The straw must then be removed from the water using tweezers, not by hand. “You should never touch the straw directly as any chemical on your hand can kill the semen, even through the AI glove.”

A lot of AI equipment is not as hygienic as it should be, says Mr Tulley. “Ensure the water used for thawing is clean and at the correct temperature specified by the semen supplier.”

“Ideally, it should take no more than 10-15 minutes from thawing to insemination and you should thaw [no???] more than two straws at a time,” he says.