The first thing to look at is the feeding regime. 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 build-up to 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.

Obesity will depress fertility. Bulls should be gradually decreased from the show diet over a period of time – this is dependent on when the bull is needed and how long the purchaser has the bull 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. They will likely be changing from predominantly starch digesters to forage-digesting bacteria. This process takes time to change – abruptly changing the diet will lead to a situation where the animal can’t absorb nutrients, leading to excessive weight loss and stress.

It is also advisable to get information from the vendor regarding the constituents of feed the bull was on before the sale, as this will aid in a problem-free transition in diets.

Fertility and health

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 purchasers.

But buyers should be aware that many different factors can affect semen production and quality after that on-farm test. Lameness, stress, fever and even exposure to disease can all lead to a bull going temporarily infertile. In many cases, these can all be avoided with proper management post-purchase.

While best efforts may have been 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’s best, if possible, to pen 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, compulsory since the introduction of the BVD Eradication Programme introduced to Ireland in 2013.

In addition, many farmers have tests carried out on newly purchased pedigree bulls to ensure they are free of disease. Despite bulls having clear BVD tests in their infancy, some farmers take no chances and test for BVD again in case bulls were exposed to a persistently infected (PI) animal at any stage.

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.

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.

Where a herd is using the live IBR vaccine, it is essential to vaccinate the bull upon arrival as a period of stress with exposure to the low levels of inactivated virus in other animals could lead to the onset of IBR in that individual. The IBR strategy for the entire herd needs to be consistent to avoid risk.

Individual vaccine programmes should ideally be discussed with your vet.

It is advised that any hoof work needed to be done on the bull be done at least a month in advance.

Those whose herds are autumn calving with bulls mating inside need to take special care. It is not advisable to have bulls working on slats or cubicles. These can lead to an increased risk to the bull.

The bull slipping could lead to injury, which may lead to premature culling or at the least losing the shape of the calving pattern due to him being unable to service. Bulls particularly need to be watched where automatic scrapers are working.

Ideally, out-wintering pads or straw bedding should be used as the location for indoor bulling. This will ensure sufficient grip for the bull when mounting, which reduces the risk of slipping.

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 the mating period to ensure they are showing normal libido.

The bull is half the herd. When implemented correctly, these small steps could be the difference between getting one year or 10 years out of the bull which is a substantial investment on any farm.

Remember

  • 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 one bull can service as many cows as he is months old. For example, a 15-month-old bull should service a maximum of 15 cows, a 20-month-old bull should service 20, 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.