Holstein bull© FLPA/REX/Shutterstock

Kings-Ransom Erdman has retained the top spot in the latest Holstein bull proof run with a profitable lifetime index (PLI) of £659. He is just ahead of his own son, United-Pride Erdman Evan (PLI £647).

According to AHDB Dairy, which compiles the genetic index figures, it is the first time in recent memory a father and son have topped the list.

Erdman himself transmits outstanding fitness, while his breed-leading lifespan index of +0.9 indicates his daughters produce milk for almost a full lactation longer than those of an average sire, AHDB Dairy said.

He combines this with good daughter fertility (fertility index +12.5) and a superb maintenance index of -23, indicating his daughters will cost less to feed for maintenance than those by other Holstein bulls.

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His son, Evan, moves up to rank second from sixth position in the previous index run.

That is because of improvements in his lifespan index (now +0.8). He displays all the hallmarks of his sire, transmitting equally good daughter fertility and low costs of maintenance, AHDB Dairy adds. At present, this bull is only available in Northern Ireland.

Moving into third position is calving ease specialist Co-op Robust Cabriolet with a PLI of £638. He has a calving ease score of +1.7 direct CE% and also transmits high percentages of fat and protein (+0.19 and +0.05, respectively) and low maintenance costs (-17).

See the top 20 Holstein bulls with genomic indexes ranked on PLI (PDF)

Young sires

Meanwhile, the young genomic sires list is dominated by Holsteins, providing compelling evidence of the speed of genetic progress within the breed, AHDB Dairy says.

There are six new entries in the top 10 since the August index run. The new headline bull for the December run is Westcoast Perseus, a very early son of Penmanship – the young sire that held the number-one position from December 2014 for 16 months.

Perseus, aged just 12 months, is out of a Doorman dam, and features high fat and protein percentages (+0.12% and +0.10%, respectively), combined with a good lifespan Iidex (+0.6) and a high daughter fertility index (+10.5). He has a PLI of £779 and a type merit (TM) of +2.37.

The second-ranking young sire is Bomaz AltaTopshot – also a newcomer to the PLI list and the highest ranking of nine top 20 sons of Cogent Supershot.

AltaTopshot has a PLI of £762 and is a transmitter of high production with a strong +41.8kg fat.

The high-type and production transmitter Endco Argo debuts in third place with a PLI of £761, a TM of +3.04 and long daughter lifespans (lifespan index +0.7).

See the top daughter-proven Holstein bulls ranked on PLI (PDF)

Other breeds

In contrast to the Holsteins, the genetic indexes for the other breeds remain remarkably stable, with little movement to report in the December run.

Unchanged at number one on the Jersey breed’s PLI is VJ Link (PLI £520), whose index shows good fitness (fertility index +11.5, SCC index -15 and lifespan index +0.5) alongside high production.

For the Ayrshires, VR Gunnarstorp Back Gobel remained in pole position with a PLI of £573 and good milk (390kg) and solids production (16.7kg fat and 12.6kg protein).

Gobel is also a breed-leading fertility and lifespan improver (FI +16.5 and LS +0.7).

British Friesian Catlane Chad (PLI £519) was again top in his breed. Transmitting good production with strong components (21.1kg (0.15%) fat and 16.1kg (0.11%) protein), this bull has good all-round fitness and calving ease, and is the best SCC improver in the top five.

See the top five breeds for non-Holsteins ranked on PLI (PDF)

Spring calving index

Jersey bulls maintain their lead in the ranking for spring calving index (SCI), but Holsteins are close behind and took two of the top five positions.

At the top of the list is the existing front-runner, the Danish Jersey, VJ Tester.

This bull’s exceptional components (+0.53% fat and +0.18% prot) together with excellent daughter fertility (fertility index +13.9), lower feed costs (maintenance -61) and low cell counts (SCC index -13), combine to earn him an SCI of £452 on this across-breed scale.