As breeding approaches fast, farmers are getting ready to start picking up cows in heat. This all important job of spotting cows in heat is getting harder. Bigger herds, cows having shorter and sometimes silent heats. Also like so many other jobs on the farm, complicated by the lack of time and labour which heat detection requires in herds.
So the modern farm increasingly relies on heat detections aids. We all know the economics of cows running late and the benefits of a tight calving pattern.
So with this in mind we use tail paint, heat mounts and more expensive technologies to help us pick up cows so we can AI them. The timing of this is AI is critical to maximising conception rates.
Many years ago I saw my veterinary experience with a very practical and knowledgable vet in Kerry. Graced with a vast mountain of technical knowledge it was often some of the simple things he told me I remember.
One such thing was when talking to a farmer about heat detection he said ‘any job you want done well requires an expert in his field’. He then said ‘if you want to pick up cows in heat you need an expert and that is a bull.
He was referring at the time to getting a vasectomised bull, firing blanks but doing the best heat detection job of all.
I learned lots of nuggets of wisdom from him while sharing the front seat of his van with the spare wheel all those years ago.
So the main advantage of a vasectomised bull, his is natural ability to do the task at hand. However nothing is quiet that simple, to get the real benefits of this expert he must be wearing a chin ball. This is full of paint and when working clearly marks cows that are in heat. This chin ball should be put on the bull about 2 weeks before breeding and the paint needs to be topped up after 15-20 mounts. This can be a bit of a nuisance but definitely gets the best results when it comes to making heat detection more straightforward.
Don’t be surprised if the young bull marks the cow all over with paint. Which in one way makes them more suitable for the job. Older bulls tend to be more experienced hitting the target leaving less of a mark.
Often vasectomised bulls are only kept for 1-2 seasons.
The surgery itself involves removing the two vas defrens tubes that carry the sperm from the testes to the outside world. I use sedation, knock the bulls down and give a large epidural which works well. I then remove two lengths of these cords (as shown in the picture) and tie off both ends. The bull requires time to heal and also may have some viable sperm in the upper plumbing works. Ideally they should not be worked for about 6 weeks after the surgery.
My preference is to do last years calves yearlings. What most of my clients do is keep 1-2 bull calves for the job. When we get them we don’t want to ware them out either. The ratio is one bull to about 50 cows.
Where they work extremely well is towards the 2nd half of breeding where there are less cows in heat. This is a time where heat activity decreases making heat detection much more difficult. Enter the expert!
We must remember they are still bulls and will carry the same risks of a stock bull regrading behaviour and safety concerns.
Some people opt to buy in vasectomised bulls which adds a risks of introducing disease. These bulls will be in close close contact with your cows and heifers so I strongly advise disease screening before purchase. We need the bull to be of adequate stature so he can mark the cows also.
My experience is that when farmers use vasectomised bulls they tend to keep using them. However you must be willing to apply chin ball and head strap correctly and top up paint regularly.
One last tip when getting bulls vasectomised always insert a nose ring making handling them easier especially when topping up paint in the chin ball.
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