With the breeding season fast approaching for autumn-calving herds, Future Beef Programme Advisor, James Mullane shares advice on bull selection and breeding enough replacements.

The sires autumn-calving suckler herds select this breeding season should be determined by the target market for the resulting progeny, along with your calving ease requirement.

Herds participating in the Suckler Carbon Efficiency Programme (SCEP) must also pay heed to the requirements for 4 and 5-star females when making breeding decisions. If heifers are to be retained than a percentage of the total sires used will need to have strong maternal traits with a big focus on the Replacement Eurostar rating and its sub-indexes, namely milk, calving interval, carcass weight and docility. In order to use enough inseminations to generate sufficient replacements, a replacement strategy needs to be drawn up for the herd.

An example of a 40-cow autumn-calving herd with a 20% replacement rate is outlined below:

• 40 cows x 20% replacement rate = 8 heifers entering the herd in 2028
• If assuming approximately 80% of potential female replacements born make it to the herd allowing for deaths, empties etc then the number of heifers born needs to be 10 to bring 8 heifers through in 2028
• Depending on whether you are using sexed or conventional straws the number of straws required are as follows:
• Sexed semen only: Need at least 2 sexed maternal type straws per heifer calf
  • 10 x 2 = 20 sexed semen maternal straws to be used
• Conventional semen only: Need at least 4 dairy straws per heifer calf
  • 10 x 4 = 40 conventional maternal straws to be used

The farmer can then switch to terminal type genetics.

The importance of sire selection when breeding

Farmers should make use of the Replacement Eurostar sub-indexes for their herd to select suitable sires for breeding replacements.

Example A: Balanced herd for milk and fertility looking to maintain milk and carcass weight and improve carcass weight and fertility.

Example B: Herd with good carcass traits but in need of improving milk and fertility.

So, from examples A and B and depending on the current make-up of the herd, a team of bulls can be selected to breed replacements. The suckler cow report should also be used when deciding which bull on your panel is allocated to a particular cow.

James Mullane is an Advisor on the Teagasc Future Beef Programme. For more tips and advice, visit the Future Beef webpage here.

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