Sir, – I read with great interest Andrew Rafferty's article in The SF on December 5, re 'Autumn pregnancy testing'.

I agree with Andrew that the artificial vagina gives a much more natural sample and allows you to check out the bull's ability to carry out natural service.

However, I object to it being described as 'old fashioned'. I have collected more than 65,000 ejaculates of semen over the years using that method and it is still used worldwide in bull studs. The reason for that, of course, is that in most cases you get a better sample than by electric ejaculation (EEJ) methods.

I am still involved in testing semen, albeit only looking down a microscope at semen collected by David Fleming using the AV method.

Regarding sometimes having to test twice using EEJ, I would say that if a bull is young enough and healthy enough in the opinion of the vet, he should never be slaughtered on the basis of semen quality if collected by EEJ.

We have tested a number of bulls which have failed by this method, on some occasions three times and they have produced excellent samples when tested the 'old fashioned' way.

Most vets are excellent at programming females to be in standing heat on the days we arrange to carry out these tests, or to carry out on farm semen collection for use in the AI industry throughout Britain.

Jim Cameron MBE

Jim Cameron Livestock Consultancy,

Newlands Cattle Breeding Centre,

Scone,

Perthshire.