Over the past few weeks and months, spring bull sales have taken place in both Ireland and the UK.

Many people highlight the issue of many bulls being overfed at these sales. However, this heavy or even excessive feeding is mainly driven by the customer.

If a bull was presented for sale in working condition, many potential customers would be turned off by this.

Until the attitude to sale body condition changes, pedigree breeders will continue to feed bulls to meet current perceived standards. This means extra feed bills for the breeder and it also means greater management of the bull post-purchase for the buyer.

Feed management

The management of a newly purchased bull post-sale is very much linked to the animal’s diet prior to the sale.

There have been many figures thrown about as to what pedigree bulls are getting in the buildup to a sale, varying from 1% to 2% of live body weight depending on breed.

So, given a 700kg bull, you would be looking at 7kg to 14kg of concentrates per day.

For this reason, purchasers should make themselves aware of the feeding regime of the bull and allow adequate time to get that bull to a “fit not fat” condition before bulling.

Gradually decreasing the amount of concentrates that make up the diet will also help to reduce the risk of problems in the rumen

Obesity will depress fertility. Bulls should be gradually decreased from the show diet over a period of time.

Again, this is dependent on when the bull is needed and how long the purchaser has the bull for beforehand.

Gradually decreasing the amount of concentrates that make up the diet will also help to reduce the risk of problems in the rumen. Rumen microbial populations need time to evolve to new diets.

Testing

Many pedigree breeders now look at fertility testing young bulls before sales as common practice, both for their own peace of mind as well as the purchaser’s. But buyers should be aware that many different factors can affect semen production and quality after that on-farm test.

Having an animal, especially a young bull, in isolation can lead to aggressive behaviour

Lameness, stress, fever and even exposure to disease can all lead to a bull going temporary infertile. In many cases, these can all be avoided with proper management post-purchase.

While best efforts may have being taken to acquire a bull from a high health herd, risk still remains. Having purchased a bull either privately or at a sale, it is best to isolate the animal on arrival for testing and acclimatisation.

Having an animal, especially a young bull, in isolation can lead to aggressive behaviour so it is best, if possible, to pen it with a cull animal already in the herd.

This way, if the bull was to fail any common disease tests it would only be an animal already destined for slaughter which stands the risk of being infected rather than the entire herd.

What tests should he pass?

Bulls should always be tested clear of bovine viral diarrhoea (BVD) virus. This is compulsory since the BVD Eradication Programme was introduced to Ireland in 2013.

Other tests for diseases such as Johne’s, infectious bovine rhinotracheitis (IBR) and leptospirosis are also routinely undertaken on pedigree farms, with many of these farms accredited. The minimum the new purchaser should be testing for relates to what their specific herd is testing for or previous issues the herd may have had.

Finally, libido can be affected by social ranking, lameness, back pain and other unknown factors

Vaccination programmes are vital when purchasing a new bull. Where a bull may have tested clear of a disease and a breeder has chosen not to vaccinate, this bull’s exposure to a herd with disease can lead to a period of infertility.

While the bull will likely regain full fertility following this period, it can prove particularly harmful to the herd’s calving pattern.

Finally, libido can be affected by social ranking, lameness, back pain and other unknown factors, so all bulls should be observed closely at the start of mating period to ensure they are showing normal libido.

Key points

  • Newly purchased bulls should be allowed time to adjust to their new environment. Adequate nutrition and exercise is essential during this period.
  • Young bulls shouldn’t run with too many cows in their first year. A general rule is that one bull can service as many cows as he is months old, eg a 15-month-old bull should service a maximum of 15 cows, a 20-month-old bull should service a maximum of 20 cows, etc. Fifty cows should be the maximum number for a mature bull.
  • Breed young bulls for a maximum of 60 days in order to prevent overuse, severe weight loss and reduced libido.