As autumn approaches, the increasing number of producers in the thick of calving at this time of year will be seeking suitable sires, and can turn their attention to the latest genetic evaluations from AHDB Dairy, ranked on Autumn Calving Index (£ACI).
A small reshuffle at the top sees Westcoast Guarantee take the lead, his ACI of £657 reflecting marginally better udder health than the number two bull, Hoanster Zanzibar (ACI £615), the bull with the edge for daughter fertility with which he swaps places. However, both these bulls excel for udder health and fertility, as demonstrated by this across-breed ranking, whose top 20 this month is monopolised by the Holstein breed.
Third ranking Progenesis Unicorn moves up, ahead of two UK-bred sires, which take joint fourth place. Both Bellemont Perks and Glamour Boghill Casper have ACIs of £595, with both show strong credentials for percentage fat.
Spring Calving Index
On the Spring Calving Index (£SCI) list, there is more of a mixture of breeds, with the top spot remaining in the hands of Jersey sire, Danish VJ Tester (SCI £467). Tester’s strong milk components earn him the lead in this slightly more components focussed index, over the higher yielding Holstein, Westcoast Guarantee, in second place.
Progenis Unicorn ranks third on £SCI, while UK-bred Glamour Bogill Casper moves up to fourth place. Hoanster Zanzibar now ranks fifth, and the high components Holstein, Mr Rubi-Agronaut joins the top tier with an SCI of £421.
“The block calving index rankings are specifically designed to suit autumn and spring block calving herds respectively, and are expressed on an across breed basis for those wishing to compare the strength and weaknesses of bulls from different breeds,” says Fern Pearston, genetics manager for AHDB Dairy. “Each index reflects the different milk and input prices through the seasons as well as the needs of different production systems, and as such, will help producers breed the most suitable cattle for their needs.”
However, she adds: “It’s very important not to look at the components of £ACI or £SCI and compare them with the Predicted Transmitting Abilities (PTAs) used in the calculation of £PLI, as these are each expressed against that breed’s average and on that particular breed scale.”
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