It’s the time of year on most farms to say goodbye and good riddance to your bulls if you haven’t already done so.

Those noisy, big eaters who like to throw their weight around are getting loaded on to whatever will take them and are finally gone.

Not one of the girls.

Hopefully they have left behind not too many broken fences, gates, troughs, water pipes and legs – yours and theirs.

WorkSafe doesn’t identify injuries from dairy bulls. Instead it lumps them together with dog bites and other injuries caused by animals on farms. However, every farmer, and every stock truck driver, knows a story.

While all cattle can be dangerous, dairy bulls rank near the top. Usually kept in small numbers, they can become territorial and are not as used to people as milking cows. As well, when one has a go at you, it’s not a 500kg animal that is knocking you down but something closer to twice that.

Some farms are going no-bull, using artificial insemination only, and it’s working financially as well as getting the cows in calf. An AI technician should get around 70% of every insemination holding, a bull is only at about 60% or worse. AI technicians get checked every season and some companies monitor their non-return rates daily. No one checks how many cows an individual dairy bull gets pregnant.

With the wide variety of semen products available, going no bull also gives you more options.

Short gestation semen is now bringing calving dates forward by as much as two weeks.

Hereford bulls, and most beef breeds, have a longer gestation period than dairy bulls which is why you will often see a gap at calving from when you stopped AI to when the cows which were naturally mated start.

Bringing calving dates forward using short gestation semen gives more days in milk, tightens up the calving spread and means fewer days dealing with new calves. It also gives late calving cows more time to get in calf the next year and can mean them not having to go a year as empties or be sent to the works.

Using sought-after beef breeds such as Wagyu under contract, Speckle Park and Belgian Blue can also give you some extra income.

But going no bull means you are looking for heats for the entire mating period – not just the four to six weeks of AI.

That’s several months of tail painting and drafting and waiting for the AI tech to arrive. And finding cows on heat is far from logical.

Just because it is on heat doesn’t mean the cow is ready to conceive. Cows which are pregnant can still come up and it takes a good technician to know what a pregnancy feels like and how not to upset it.

A range of products and systems deal with these problems from wearables such as cow collars and ear tags that pick up heats so there is no need for tail painting, automatic drafting gates and heat detecting stick-on pads.


Early scanning is also a good idea. A pregnancy can be detected from about 28 days by manual palpation or ultrasound scanning by your vet.

Finding the phantom pregnancies – cows which have been mated and have not come back on heat but are not pregnant – gives you the option of treating these cows with hormonal interventions to bring them back into heat.

But remember PG shots and CIDRs are a tool, not a cure. Feeding and animal health is all important to get cows in calf and to stay in calf.

A mix of AI and bulls can also work and means you don’t have to invite so many bulls on to your farm.

Teaser bulls (vasectomised bulls) can work well to identify cows on heat but the operation is not cheap. Better is to run a young beef bull with the herd from the start of mating.

With hundreds of cows to ride, he’ll be shooting blanks but he’ll stir things up and keep mating rolling along. Any calves he does manage to sire will be easily picked up as they will have beef markings.

Or, if things start going a bit quiet and there are still lots of cows to come up for AI, stick the bulls in for a night. They’ll remind the girls what they’re meant to be doing and AI will be back on track again.

Extending AI to six weeks or more will mean you also need less bulls when you stop. The recommended bull-to-cow ratio is one bull to 20/30 cows. It means if you only have 50 cows left which haven’t come up for AI you can get away with two to three bulls and add a fourth one for returns.

If you finished AI with still 100 cows left you will have to double the number.

If you are depending on the bulls getting cows in calf make sure there are at least two bulls per mob, just in case one is having an off day. However, you may be tempted to have just one bull per mob, especially as two bulls can unfortunately spend more time fighting with each other than charming the girls.

Make sure bulls are vet checked before you spend money on them. This will make sure they have enough of the good stuff and will not spread any diseases (especially BVD).

Go and see them before they are delivered. Make sure they are fit, have no issues getting around, and are the right weight for their age. Bulls should be at a body condition score of 4.5 to 5.5 prior to mating.

They will lose condition over mating and if they are too busy eating instead of doing the business, don’t expect them to get your cows in calf.

Walk through them looking for aggressive behaviour. If you can’t walk through them in the paddock how do you expect to handle them in the dairy yard? If they stalk you, leave them there.

Make sure they are delivered to the farm at least 10 days before they are needed so they can settle in and get over any soreness from trucking.

During mating keep an eye on them. If you have multiple herds, move the bulls between them to minimise any problems. Any bulls which go lame or lose too much condition will need to be replaced so make sure you have a few spare if you need them.

Infections, antibiotic treatments and elevated temperatures can affect sperm production for a month or more.

Looking after your bulls will make sure they can look after your girls.