I try to pride myself in achieving good conception rates with artificial insemination (AI), but there are also times when I can feel really disappointed with how it has turned out.

This winter I have (in my opinion) an excellent batch of breeding heifers earmarked for calving down next autumn. There were just over 30 to start with.

I went through them hard, even though all had good maternal genetics. In the end I only decided to breed 25 of them, with anything that was too small, or had temperament issues, left to the side.

I dosed and vaccinated them well in advance of starting to breed.

They were well settled into the house and on excellent quality silage and meal.

I chose two top-quality proven bulls to use. One was sexed female semen, and the other was conventional semen.

I had pre-recorded heat dates, so I was looking forward to a successful breeding season.

Of course, all this is no guarantee of success – how you can be cut down very quickly!

Repeat

I had only 13 sexed straws, so I used them on the first 13 heifers that I saw in heat. Then I moved on to the conventional semen.

I noticed a lot of heifers were putting blood out a couple of days after being artificially inseminated, so I started doubting myself. I started to wonder if I should bring some other semen into the equation. I chose two more bulls with good genetics, although this time they were unproven.

When the first three weeks of breeding were finished the heifers started to repeat, and I was starting to worry. I normally only inseminate heifers for eight weeks, so if there was a problem with the semen I would not get much of a chance to put it right.

From then on, I went with the two unproven bulls.

I scanned the heifers last week and it made for interesting reading, especially when everything was set out on paper in front of me.

Out of the 13 sexed straws, which I used, I have six heifers in-calf. I then used 10 straws from the really good, proven, conventional straws, and only had four more in-calf. Then I moved on to the two unproven bulls for the repeats.

So far, I have 12 out of the 15 remaining heifers scanned in-calf. The last couple are not long enough inseminated to know, for sure.

I have been scanning my cows, heifers and sheep for a number of years, and it is an important part of management on this farm. I like to get it done as soon as possible – it’s probably the desire to know for sure what’s going on.

That said, I would have been fairly confident that most of the heifers were now in-calf, but the scanning puts it beyond doubt. In most things I continually doubt myself, and need some form of certainty.

Semen

Looking back through my scanning results it looks like there was an issue with the semen I was using at the start, although, when some of the heifers proved in-calf, it is very difficult to be sure. It, also looks like the last two batches of semen I used were excellent.

Having said all that, it could just be my own fault in not doing the inseminating work to a high enough standard.

I know, from years of experience, that some AI straws are not as good as others.

No one who is selling AI straws will ever tell you that, but I have seen a wide variation in the conception rates of different bulls.

But this is just speculation. For me, the most important thing is to get the scanning completed and find out what is going on in both the cattle and the sheep.