As spring-calving approaches, block-calving producers placing a heavy reliance on grazed grass can look to the Spring-Calving Index (£SCI), for the most profitable sire selection options.

Figures from the latest bull proofs, published by AHDB Dairy, show the daughter fertility improver, Progenesis Unicorn remains the No 1 bull ranked on SCI, at £485.

He is followed by Progenesis Wimbledon, from the same breeding programme, whose SCI of £472 reflects the bull’s transmission of high milk solids, as well as lameness reduction and fertility improvement – all key traits for spring, block-calving herds.

New entrants in places three to five are Schoene AltaRobert (SCI £457), Peak Motion (SCI £456) and VH River Ramsey (SCI £441). Although £SCI is an across-breed index, the top five bulls in this proof run are all from the Holstein breed.

Autumn calvers

Autumn block-calving herds will have to wait longer to use some brand-new genetics, with three sires making their debut at the top of the Autumn-Calving Index (£ACI) ranking.

Progenesis Wimbledon features in No 1 position, matching his pole position achieved in the Profitable Lifetime Index (£PLI) ranking. His ACI of £661 indicates he is just as suited to autumn, block-calving as year-round calving herds.

Wimbledon is followed by second placed VH River Ramsey (ACI £633) and Peak Motion in third (ACI £632).

Remaining in fourth place is Progenesis Unicorn (ACI £629) and rounding off the top five is a former number one £ACI sire, Westcoast Guarantee (£619).

With both £SCI and £ACI expressed on an across-breed basis, these rankings allow those who wish to assess the strengths and weaknesses of bulls from different breeds to make ready comparisons.