As we get closer to the start of the autumn calving season, it is important to have a think about selecting bulls for your herd, as the sires you put to your cows will dictate your productivity and help fulfil your winter milk contract.
Although it is still early days yet, farmers should start planning for the breeding season now in order to match up bulls and get the sire selection right.
Time and effort should be put into your breeding plan to ensure best genetic gain is achieved.
The aim for any breeding programme, whether it is an autumn calving herd or a spring calving herd, is to improve on milk solids while improving on fertility traits, such as calving interval and six-week calving rate.
For an autumn calving herd, you must be aiming to breed a cow with good efficiency, health and longevity, and the economic breeding index (EBI) balances these objectives.
Selecting bulls
Before selecting for sires, a farmer must identify when they are going to start and finish the breeding season.
For the majority of winter milk herds (<50% liquid contract), starting to calve in October will work to meet your contract targets.
Milking cows during the winter is expensive, as they are milking off silage and meal which is not cheap, so, not oversupplying or undersupplying your contract is crucial.
Using your herd’s records, identify the lower performing cows and either mark them for culling or breed them to high Dairy Beef Index (DBI) bulls.
You should avoid breeding your replacements off cows with poor milk solids, poor temperament, poor fertility, high somatic cell count (SCC), or cows that are lame or have any other issues.
Each herd will have its own breeding objectives and targets. However, targets for farmers using the economic breeding index (EBI) should be similar to what is outlined in the table below.
Value EBI €270 Fertility sub-index €120 Production sub-index €100 Maintenace sub-index €5-15 Health sub-index €5 Carbon sub-index Positive Protein +0.17% or 3.97% Butterfat +0.25% or 4.90% Milk solids +35kg
The targets outlined above are set for a team of bulls being used on autumn-calving herds and the bulls should be selected from the active bull list. At least seven bulls should be used for 100 cows.
Farmers should work out how many replacement heifers are required for their farm and work out how many conventional or sexed straws they will need to breed the number they want.
By doing this, farmers can then work out how many beef straws they will need for the remainder of the herd.
By planning this out now, the farmer will be able to produce the right amount of replacement heifers needed while maximising profits by producing quality beef calves that are easily sold.
Two to three bulls should also be selected with low calving ease proofs for use on the replacement heifers.
The aim should be to breed all replacement heifers in the first 10 days of the breeding season, and quite often the best of doing this is through a simple synchronisation programme.
Getting your breeding season right and selecting the right bulls for your herd is essential for future milk production and for fulfilling winter milk contracts.