Genosource Jumpstart P heads young Holstein sire ranking

Strong health and production credentials have put a new bull at the top of the latest AHDB young Holstein sire evaluations, published 11 August.

Genosource Jumpstart P transmits 56.8kg (+0.28%) fat and 35.9kg (0.12%) protein, alongside a favourable mastitis index of -2.

These scores earn Jumpstart – whose sire, Genosource King P, is in 12th position – a profitable lifetime index (PLI) of £919. Both bulls have the added advantage of being polled.

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Climbing into second place, with a PLI of £917, is Genosource Judo, the highest milk and protein bull in the top 20.

He shares the highest EnviroCow score among the leading bulls with (third-placed on PLI) Peak AltaSpinwin, at +4.9. Spinwin – one of three AltaMakeover sons in the top 20 – combines strong production with a maintenance score of -24kg and a daughter fertility index (FI) of +6.8. He has a PLI of £907.

OCD Thorson Ripcord is in fourth (PLI £905), with strong efficiency credentials: a maintenance index of -32kg and fertility index of +10.3.

Fifth place, with a PLI of £891, goes to new entrant Genosource Hemi, thanks to traits including 153 days of extra lifespan and an FI of +11.5. These contribute to a strong HealthyCow index of £249.

“What stands out in this evaluation is that the top bulls no longer excel in just one area,” says AHDB’s head of animal genetics, Marco Winters.

“Today’s leading sires combine strong milk solids with improvements in health, fertility, efficiency and environmental performance, giving breeders greater confidence that genetic gain can be achieved without compromise.”

Daughter-proven sires

Daughter of OCD Trooper Sheepster © Lea Jordan/Cybil Fisher Photography

OCD Trooper Sheepster tops the PLI rankings for daughter-proven sires with a balanced package of health and fitness traits (PLI £756).

He also has strong production credentials, including predicted transmitting abilities for fat of 48.7kg and +0.19%.

Genosource Captain (PLI £744), now backed by more than 4,000 UK daughters, is in second place, with a feed advantage (FAdv) of +271kg.

This means his daughters are predicted to save 271kg of dry matter intake compared with average FAdv daughters of similar production.

Lars-Acres SSI GD Raiton moves into third place (PLI £732).

He transmits the highest milk production in the top 10, at 1,399kg, has a mastitis index of -2 and a somatic cell count (SCC) ranking of -19.

OCD Fugleman Radical, in fourth (PLI £715), is a new entry, with daughters predicted to live 128 days longer than average on lifespan index.

In fifth place is Pine-Tree Denovo Avon (PLI £705), thanks to an exceptional daughter fertility index of +7.2, low maintenance costs (-33kg) and a lameness advantage of +4.5%.

Sires for block-calving herds

Holstein sire Winstar Graziano retains his lead in AHDB’s across-breed ranking for autumn block-calvers. This is weighted towards the need for good fertility and the costs of producing winter milk.

Winstar Graziano © Holly McFarlane

Graziano increases his autumn calving index (ACI) to £594 with outstanding fat and protein production and SCC.

High milk and fat production plus favourable maintenance move Pine-Tree Denovo Avon up into second place (ACI £567), while daughter fertility improvements and SCC reduction earn polled sire FB 442861 Knighton P (ACI £553) third spot.

Energy efficiency, fertility, health and functional traits are reflected in the spring calving index (SCI).

This is led by Jersey bull VJ Grand Maronnier Dandi Bell, who transmits strong milk and solids production and an excellent maintenance score. He has an SCI of £491.

VJ Grand Maronnier Dandi Bell © Gejp

Rising to second place is VJ Kjoelby Higher Highlan (SCI £422), with outstanding fat and protein percentages. VJ Boman Lasky Lando ranks third (SCI £414), combining strong udder health traits, daughter fertility and maintenance.

The complete list of sires for these indexes and other breeds.