Teagasc and the Irish Cattle Breeders’ Federation (ICBF) recommend that teams of bulls are used when breeding dairy cows.
Margaret Kelleher from ICBF recently stated: ”Select a team of high economic breeding index (EBI) artificial insemination (AI) bulls when breeding your dairy replacements.
For a typical 100-cow herd, a minimum of eight sires should be used on your herd, with no more than 15% of matings to any one bull.
”This is the advice regardless of whether the sires are genomically or daughter proven. The key message is when planning what bull to use, also plan how to use each bull equally.”
Image source: ICBF
“Invariably bulls are only proven for milk traits and not for female fertility traits which remains a key issue for dairy farmers,” Margaret added.
”If you want to improve fertility and other traits related to fitness on your farm, then you need to use teams of bulls.
Nationally, farmers tend to use a sufficiently large team of bulls. The common mistake made by many is that an individual bull in the team can be overused.
”Typically, 34% of calves in dairy herds are sired by one bull and this is too high. The risk is that if the bull should subsequently fall in EBI, then the genetic merit of the progeny will also be affected.”
Margaret concluded by stating that: ”the key message is when planning what bull to use, the farmer should also plan how to use each bull equally across the herd”.
”For herds of 100 cows or less, a minimum of seven bulls are recommended – more sires will be required for larger herds.”