10% of spring-calving cows should calve after April 1

Nationally, 389,000 cows calved between April and June in 2019 and 2020

Teagasc is recommending that a compact calving pattern be maintained in spring calving for dairy herds. File Picture. 

Nationally, an average of 389,000 cows, or just over one-quarter of spring-calving dairy cows, calved between April and June in 2019 and 2020, with almost as many of the cows calving in May and June as in April.

This is improving over time, but the target is that only 10% of spring-calving cows should calve after April 1.

Teagasc recommends a compact calving pattern is maintained in spring calving for dairy herds.

The reason for this is because it offers the best alignment of pasture demand and pasture growth rates.

Such systems rely upon excellence in terms of breeding management.

The key reproductive targets in seasonal calving dairy herds include a 90% six-week calving rate; a 365-day calving interval; and a planned empty rate of less than 8% at the end of a 12-week breeding season.

Breeding guidelines for spring 2021

nKnow your herd’s strengths and weaknesses.

Refer to your Irish Cattle Breeding Federation (ICBF) herd Economic Breeding Index (EBI) scorecard to help establish what these are.

n Select a team of high-EBI AI bulls, when breeding your dairy herd replacements.

For a typical 100-cow dairy herd, a minimum of eight bulls should be used, with no more than 15% of matings to any one bull.

n Target high-EBI females (typically maiden heifers, and first and second calvers) to breed your next generation of dairy herd replacements.

Lower-EBI cows should be bred to beef AI from the start of the breeding season.

n Use the Dairy Beef Index to select suitable beef AI sires for your dairy herd.

A team of bulls should be selected that suits the various dams in your herd (maiden heifers, young cows and mature cows) and the number of these that are selected for beef AI.

Bulls with higher beef merit figures should be selected for older animals.

Consider the use of vasectomised bulls, in conjunction with beef AI, as an alternative to beef stock bulls. Avoid using dairy ‘sweeper’ bulls.

n Use the ICBF HerdPlus Sire Advice Tool to help manage your breeding programme and simplify the process of sire selection.

It will allocate your bulls to cows based on their strengths and weaknesses, as well as managing in-breeding.

Cows designated for beef AI should be flagged, to ensure that only the best animals are used to breed dairy herd replacements.

For more information on this tool, speak to ICBF HerdPlus, your Teagasc advisor and/or your AI company.

n If using sexed semen, only use high-EBI sires, and ensure that all sexed semen inseminations occur early in the breeding season.

Any inseminations with Jersey or crossbred bulls should be conducted using sexed semen only.

Pay careful attention to straw handling and AI procedures, as sexed semen contains fewer sperm, and these sperm are more fragile after the sorting process.