Autumn block calving herds poised to choose their next generation

As autumn calving steps up a gear across many of the UK’s block calving herds, attention turns to breeding decisions to produce the next generation of dairy heifers. 

The Autumn Calving Index (£ACI), published today by AHDB, is the recommended genetic index where autumn calving is in a tight block, and is weighted in particular towards the need for good fertility and the costs of producing winter milk, amongst other traits.

The efficiency of the Holstein in these situations shines through, and the black and white sire, Winstar Graziano retains his previous lead in this across-breed ranking. Graziano increases his ACI to £594 and continues to demonstrate outstanding fat and protein production with excellent somatic cell count performance.

One of the biggest movers this time is Pine-Tree Denovo Avon, who climbs into second place with an ACI of £567. Avon delivers high milk alongside a high weight of fat, and does so while achieving very favourable maintenance costs.

Rising into third place is FB 442861 Knighton P, with an ACI of £553. This polled sire achieves his position through a combination of daughter fertility improvements and cell count reductions.

New entrant, Denovo 18452 York PP, ranks fourth, with an ACI of £537, bringing together outstanding milk components with the added attraction of homozygous polled genetics. Rounding off the top five is OCD Trooper Sheepster (ACI £534), whose daughters are predicted to deliver exceptional production.

Sixth-ranked Bomaz Heisman follows closely at £532, combining strong production and type traits, while Denovo Invictus remains among the leaders in seventh. His ACI of £531 reflects exceptional daughter fertility, longevity and all-round fitness.

At £526, the new entrant, DG Space takes eighth position, offering a balanced package of production and health. Completing the top 10 are Denovo 17121 Sargent (ACI £521) and Winstar Maserati P (£518), both transmitting favourable lifespan performance.

Spring Calving Index (£SCI)

For those thinking further ahead towards spring breeding, there’s a new leader for Spring Calving Index (£SCI), designed specifically for grazing based systems in tight block calving herds.

The Jersey bull, VJ Grand Maronnier Dandi Bell climbs from 22nd place to claim the number one position, his SCI of £491 reflecting strong improvements in milk and solids production with excellent maintenance costs.

Rising into second place is VJ Kjoelby Higher Highlan on £422, driven by outstanding fat and protein percentages. VJ Boman Lasky Lando ranks third at £414, combining excellent daughter fertility, favourable maintenance and strong udder health traits.

Denovo Invictus remains the leading Holstein sire in this across-breed ranking, which is dominated this month by Jerseys.

Taking fourth position with an SCI of £408, his performance is backed by more than 3,200 UK daughters, and he continues to offer outstanding daughter fertility together with exceptional improvements to somatic cell count.

The next placed bulls are VJ Christiansborg Steno Shine (SCI £397) and VJ Risholm Luxi Lagoa P (£396), both ranking highly for maintenance efficiency.

In seventh and eighth positions are VJ Adelgaard Domino Danka (SCI £393) and VJ Outrup Luxi Luxplus (£387). Both bulls offer excellent milk components, with Luxplus also standing out for daughter lifespan.

Ninth-placed VJ Ravninggaard Huus Hamlet (SCI £381) continues to impress for daughter fertility, while FB 442861 Knighton P completes the top 10 with an SCI of £353.

This Holstein sire combines high milk, fat and protein yields with exceptional resistance to mastitis as reflected in his SCC performance.

Victoria Ashmore, Animal Genomics Manager at AHDB, said:

"Grazing-based producers calving in a tight block in spring attach a particular importance to energy efficiency, fertility, health and functional traits, and the £SCI reflects these demands.

"Variety continues to be offered in this ranking with 11 of the top 25 bulls carrying the Viking Jersey (VJ) prefix, while New Zealand-bred sires retain a strong presence, with seven bulls represented in the top 25."

No comparison

Block-calving producers are reminded not to compare the component figures of the £SCI or £ACI with those used in the calculation of Profitable Lifetime Index as £PLI is calculated at a breed level, whereas the seasonal indexes are expressed across the breeds and, hence, use a different average.