UK dairy genetics reach new heights as type leaders emerge from August evaluations
EXECUTIVE SUMMARY: The August 2025 UK Holstein genetic evaluations delivered an unprecedented transformation of the breed’s leadership rankings, with six new daughter-proven sires graduating into the top 10 Profitable Lifetime Index (£PLI) positions and displacing established industry leaders. OCD Trooper Sheepster emerged as the new frontrunner with a commanding PLI of £779, showcasing exceptional production traits (47.8kg fat, 35.7kg protein) and an impressive +113 days lifespan improvement, while Peak AltaSeverus claimed second position at £757 PLI with outstanding daughter fertility (+12.8) and mastitis resistance (-25 SCC). The genomic young sire rankings experienced an equally dramatic reshuffling, with Peak AltaValuepack ascending to the top spot at £877 PLI, demonstrating the rapid evolution of Holstein genetics through superior health traits (£203 HealthyCow rating) and feed efficiency (-17 Maintenance Index). Most significantly, former long-term industry standard-bearer Genosource Captain, despite maintaining over 2,000 UK milking daughters in his proof, dropped to fifth place at £723 PLI, marking the end of an era and highlighting how quickly genetic progress can reshape breeding hierarchies. This comprehensive reordering reflects the dairy industry’s accelerating focus on health, fertility, and feed efficiency traits that directly impact farm profitability, while demonstrating that genomic predictions are proving remarkably accurate as young bulls transition to daughter-proven status. The UK’s August geonomic evaluations have just proven that genomic bulls are no longer the “risky” choice – they’re the profitable one. Peak AltaValuepack hit £877 PLI while maintaining exceptional longevity (+122 days), and Denovo Pinedale appeared out of nowhere with component genetics that could boost your milk check by $200+ per cow annually.
The August 2025 UK Holstein genetic evaluations have delivered some of the most significant ranking changes in recent memory, with new leaders emerging across both daughter-proven and young genomic categories, signaling a dynamic shift in the UK’s dairy breeding landscape.
Daughter-Proven Bulls See Leadership Change
Six new daughter-proven sires have graduated into the top 10 ranking for Profitable Lifetime Index (£PLI), marking a significant milestone in demonstrating the reliability of genomic predictions. These Holstein bulls have transitioned from the genomic young bull rankings and now provide concrete evidence, through their daughters’ performance, of their ability to enhance health, fertility, and production efficiency across UK herds.
OCD Trooper Sheepster leads this new cohort with a PLI of £779, showcasing exceptional production capabilities with strong Predicted Transmitting Abilities of 47.8kg fat and 35.7kg protein, complemented by an impressive lifespan improvement of +113 days.
Peak AltaSeverus claims second position with a PLI of £757, distinguished by outstanding daughter fertility (+12.8) and remarkable ability to reduce cell counts and mastitis incidents (-25 SCC, -1 Mastitis), contributing significantly to herd health improvements.
SDG-PH Delux Dominance ranks third at PLI £741, offering practical reproductive advantages through shorter gestation length (-4 days) and improved calf survival (+2.8), traits that enhance overall herd management efficiency.
The fourth position belongs to Winstar Maserati (PLI £728), notable for high fat transmission (+0.33%) and strong daughter Fertility Index (+9.6), resulting in an excellent HealthyCow value of £215.
Genosource Captain, the former long-term frontrunner, maintains fifth place with PLI £723, supported by over 2,000 UK milking daughters in his production proof. His continued high ranking reflects exceptional feed cost-saving traits, including Maintenance (-28) and Feed Advantage (+255).
Plain-Knoll Renegad Trooper, sire of the new leader, holds sixth position (PLI £715) and dominates the top 20 for Lifespan (+174 days). The seventh and eighth positions are occupied by Progenesis Wesson (PLI £712) and Denovo 17579 GIP (PLI £701), both excelling in Maintenance (-25) – among the best figures for daughter-proven sires, demonstrating how improved genetics deliver tangible production efficiencies through reduced feed costs.
Completing the top 10 are Denovo 16767 Pinedale and Winstar Graziano, both tied at PLI £698. Pinedale transmits outstanding milk components (+0.48% fat, +0.21% protein), while Graziano excels in udder health (-24 SCC, -1 Mastitis).
Marco Winters, Head of Animal Genetics at AHDB, emphasized the significance of these results: “The six new graduates in the top 10 already have around 7,000 heifers registered in UK milk-recorded herds, with some now milking. Their proven £PLI values deviate by just one point on average from their earlier genomic predictions, highlighting the reliability of genomics and the clear advantage for producers who use genomic bulls early.”
This remarkable accuracy validates the confidence farmers can place in genomic evaluations when selecting young bulls, providing assurance that early adoption of superior genetics will deliver the expected genetic progress in their herds.
Young Genomic Bulls Witness New Frontrunner
The young genomic category has seen equally dramatic changes, with Peak AltaValuepack emerging as the new leader at £877 PLI (66% reliability). This balanced performer offers +785kg milk with strong components (+0.17% fat, +0.10% protein) and exceptional longevity (+122 days Lifespan), representing the modern ideal of comprehensive genetic merit.
Top 5 Young Genomic Bulls – August 2025
| Rank | Bull Name | PLI £ | Reliability % | Milk kg | Fat % | Protein % | Lifespan (Days) |
| 1 | Peak AltaValuepack | 877 | 66 | +785 | +0.17 | +0.10 | +122 |
| 2 | Denovo 20771 Segment | 876 | 66 | +971 | +0.16 | +0.06 | +116 |
| 3 | Denovo 20893 Harmony | 875 | 66 | +1116 | +0.10 | +0.05 | +92 |
| 4 | Progenesis Preston | 862 | 66 | +978 | +0.16 | +0.10 | +85 |
| 5 | Denovo 20723 Columbia | 856 | 66 | +1135 | +0.04 | +0.03 | +98 |
Denovo 20771 Segment climbs to second place at £876 PLI, up from fourth position in April with a remarkable 21-point gain. His high-production profile (+971kg milk) combined with solid health traits makes him a compelling choice for high-input systems.
The former leader, Denovo 20893 Harmony, drops to third at £875 PLI after losing 6 points since April. Despite the decline, Harmony remains a production powerhouse, with +1,116 kg of milk and outstanding calving ease (-2.38 CS).
Type Merit Excellence Continues
In the type merit rankings, Siemers RZ Pazzle 34954 has claimed the daughter-proven crown with an exceptional 3.23 TM score, overtaking April’s leader Siemers Rengd Parfect. His standout mammary system (2.67 MAM) and excellent feet & legs (2.27 L&F) demonstrate superior conformation genetics.
Top 5 Type Merit Daughter-Proven Bulls – August 2025
| Rank | Bull Name | TM Score | PLI £ | MAM | L&F | LOC |
| 1 | Siemers RZ Pazzle 34954 | 3.23 | 427 | 2.67 | 2.27 | 1.86 |
| 2 | Koepon Marpon | 2.94 | 511 | 1.59 | 2.47 | 2.92 |
| 3 | Sandy-Valley Esquire | 2.92 | 570 | 2.03 | 2.16 | 2.17 |
| 4 | Bomaz Rimrock | 2.83 | 435 | 2.52 | 1.85 | 2.05 |
| 5 | Regan-Danhof Capone | 2.82 | 548 | 2.13 | 2.42 | 2.50 |
MAM = Mammary, L&F = Legs & Feet, LOC = Locomotion
Among young genomic bulls, AOT Hampshire maintains his leadership position with 2.93 TM, though slightly down from his April score of 3.04. His consistent performance in mammary (2.23 MAM) and locomotion (2.28 LOC) traits keeps him at the forefront of type breeding.
Top 5 Type Merit Young Genomic Bulls – August 2025
| Rank | Bull Name | TM Score | PLI £ | MAM | L&F | LOC |
| 1 | AOT Hampshire | 2.93 | 347 | 2.23 | 2.12 | 2.28 |
| 2 | Mystique Animation | 2.79 | 491 | 2.89 | 1.86 | 1.85 |
| 3 | Progenesis Dinabeast | 2.75 | 538 | 2.58 | 1.94 | 1.61 |
| 4 | Synergy Peak AltaBenito | 2.72 | 558 | 2.23 | 2.34 | 2.19 |
| 5 | Stantons Right Stuff PP | 2.67 | 511 | 2.25 | 1.81 | 1.29 |
- UK – PLI Young Genomic Bulls – 08/25
- UK – PLI Daughter Proven Bulls – 08/25
- UK – TYPE Merit Young Genomic Bulls – 08/25
- UK – TYPE Merit Daughter Proven – 08/25
