With the spring breeding season well and truly upon us, producers using grazing based systems will find a reassuring consistency amongst bulls ranked on Spring Calving Index (£SCI), published by AHDB.

Progenesis Wimbledon remains in number one position, his lower milk volume and high components, combined with a very high daughter Fertility Index and shorter than average gestation lengths, contribute to his SCI of £588.

This Holstein bull’s genetic performance on this across-breed ranking, stands just ahead of second placed Denovo Invictus (SCI £552). With 427 UK milking daughters contributing to his high-quality milk index, Invictus also breeds smaller sized daughters which will improve maintenance feed costs.

New Zealand-bred Diggs Hardcopy holds on to third position with excellent fat and protein percentages and high fertility all contributing to his SCI of £550.

A new entrant in fourth position is the leading Holstein £PLI sire, Genosource Captain (SCI £546), who will transmit more production than the typical bull at the top of the £SCI list.

The Jersey bull, VJ Groenbjerg Lobo Lobster moves up into fifth (SCI £537) transmitting the high milk components and smaller body size typical of the Jersey breed, combined with high daughter lifespan.

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VJ Hoeholt Jern James – another Jersey with high milk quality traits – moves up from 20th position to now rank sixth (SCI £535), while the next three places are held by sires which previously ranked in the £SCI top 10. First is the Holstein bred Pine-Tree CW Legacy, with excellent udder health characteristics; and next are the Danish Jerseys, VJ Zummit (SCI £525) and VJ Ravninggaard Huus Hamlet (SCI £520). Zummit transmits slightly higher yields with more favourable maintenance, whereas Hamlet displays higher fertility and lifespan traits.

Rounding off the top 10 is the Holstein, Denovo 7921 Atrium (SCI £519), with high milk solids and good udder health.

£ACI

Producers calving in an autumn block may also look to the versatile sire, Genosource Captain, who takes the lead in the £ACI ranking with an ACI of £708, having graduated from the genomic list.

Progenesis Wimbledon moves up into second (ACI £677), and last time’s number one, Pine-Tree CW Legacy ranks third (ACI £661).

Denovo Invictus (ACI £645) makes significant gains on adding UK daughters, moving up to fourth position ahead of Aardema Pistolero (ACI £641).

Three familiar bulls – Westcoast Guarantee, FB 326856 Medley Baynes and Bomaz Monument-P – all weigh in with £ACIs of £631 in equal sixth position.

Cell count improver, Westcoast River, ranks ninth, ahead of Bomaz Complex, bringing up the rear in 10th position.