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Archive: New Spring Calving Indexes are ready for breeding season

Published 2 December 14

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As the breeding season approaches for grazing-based, spring-calving herds, producers can look to the new Spring Calving Index (£SCI) to help with their sire selection.

Within the list they will find bulls of every dairy breed, ranked on this first across-breed index ever published by DairyCo.

“The index was launched in August specifically for herds which block calve in spring, place a heavy reliance on grazed grass and are targeting annual average production of around 4,500 litres,” explains Marco Winters, DairyCo head of genetics.

“Now spring-calving herds are considering their breeding choices, I’d recommend using this index which is designed for the UK climate and economic conditions,” he says.

With little change in ranking since the inaugural run, he says the list particularly helps breeders who are considering cross-breeding their herds.

“All of the main dairy breeds are represented in the top 100 list, which means there really is something for everyone whatever their breed preference,” he says.

Scanning the list reveals the particular strengths of one breed above another including the low maintenance costs (negative figures) of the Jersey, the higher volumes of milk and weights of fat and protein of the Holstein and the fertility of the British Friesian.

“However, within each breed we also find significant variation, meaning that farmers have to be mindful of which bull they choose within breeds,” he says.

“We hope the list will help farmers select the right bulls to meet their breeding goals, while also maintaining the traits to suit their farming system,” he adds.

“These bulls have been identified as those with the greatest potential to generate profit when producing spring milk from grass, where costs of production are quite different from those in traditional, supplement-fed herds.

“For this reason, I must stress that the index is unsuitable for other dairy farming systems, including those which are block-calving at other times of year,” he adds.

He also adds a warning about using the Predicted Transmitting Abilities (PTAs) on the £SCI table which must not be compared with any other PTAs.

“The £SCI and its constituent PTAs are calculated against their own genetic scale and base, derived from an average of several breeds,” explains Mr Winters. “They are only intended for comparison against one another and should never be compared with the constituents of the Profitable Lifetime Index.” 

Full details of the new £SCI and a list of the top ranking bulls are on the DairyCo Breeding+ website at www.dairycobreeding.org.uk