As the breeding season kicks off on many Irish dairy farms, farmers are turning out their stock bulls with the cows. The good weather and grass growth have arrived just in time, and the breeding season appears to be progressing well. As farms move into week five and six, many will be considering turning out the stock bull to clean up any cows that remain not in calf.
It is important to continue using artificial insemination (AI) for at least a few days when the stock bull is turned out with the cows. This gives the bull a chance to get up to speed and ensures that there is no break in the calving season. Farmers should also have a rough idea of how many cows might not yet be in calf, as the number of bulls needed may differ. For a 100-cow herd, with approximately 50-70% of the herd in-calf after six weeks of AI, at least two bulls will be required. If less than half of the herd is in-calf after six weeks of AI, three bulls will be required.
When a bull is running with the cows, extra safety precautions are necessary. A bull should never be trusted, no matter how quiet he seems. Farmers should always know where the bull is when herding the cows. Ideally, a vehicle should be used, and at the very least, a stick should be carried. Farmers should keep close to the fence line and always have an escape route planned as there is always potential that it will be needed. If there are any signs of aggression shown by the bull, they should be moved on from the farm.
Farmers should also be aware of the potential for bull infertility. Bulls can become infertile due to a variety of reasons, such as poor nutrition, disease, or injury. It is recommended that farmers have their bulls fertility tested before the breeding season to ensure that they are capable of doing their job. If a bull is found to be infertile, it is important to replace them as soon as possible to avoid a break in the calving season.
In addition to bull infertility, farmers should also be aware of the potential for inbreeding. Inbreeding can lead to a decrease in fertility, as well as an increase in the likelihood of genetic disorders. Farmers should keep track of the pedigree of their cows and bulls to avoid inbreeding. It is recommended that farmers use a breeding advisor to help them make informed decisions about which bulls to use.
Overall, the breeding season is an important time for dairy farmers. By taking precautions and being aware of potential issues, farmers can ensure a successful calving season and a healthy herd.