The Proven Sire List for the Holstein Breed Ranked on £PLI

A former number one genomic sire has become the leading daughter-proven sire this week (5 April) in the AHDB Profitable Lifetime Index (£PLI) rankings. With a PLI of £777, Denovo 14566 Crosby takes pole position with an exceptional Calf Survival Index of +6%, great udder health indexes (-22 SCC, -2 Mastitis) and solid Predicted Transmitting Abilities (PTAs) for production. A son of DG Charley, Crosby also transmits good resistance to bovine TB, with a TB Advantage of +4.4.

In second position is a former number one proven sire, Westcoast Yamaska, whose outstanding protein PTAs (35.1kg, +0.18%), high fat (+0.23%), and good daughter Fertility Index (+9.1) help earn him a PLI of £761. Yamaska now has 887 UK milking daughters contributing to his figures.

A new entry in third position is Bomaz Montreal (PLI £747), the highest fat transmitter in the ranking at 54.7kg and +0.36%. He also has a good Lameness Advantage (+3.0) and a strong rating for EnviroCow (+3.6).

Climbing into fourth position is S-S-I PR Renegade (PLI £729), with a high daughter Fertility Index of +11.1, and 32.8kg PTA fat.

Pine-Tree-I Pursuit moves up to fifth position, featuring high daughter lifespan (LS +162 days), a good HealthyCow Index of 247 and the highest Type Merit in the top 20 at +2.06.

Sixth place is shared between stable mates ABS Zebedee and Denovo 8084 Entity at £709 PLI. Zebedee transmits the higher production (925kg milk, 48.3kg fat and 34.5kg protein), with Entity rating better on HealthyCow (196).

Another exceptional fat transmitter at 51.8kg is ABS Crimson, the bull which now ranks in eighth position (PLI £705). Crimson shares this place with UK-bred Stowey Magician, himself strong for daughter fertility (FI +16.2), which contributes to his high HealthyCow of 271.

Rounding off the top 10 is Melarry Frazz Arrowhead, another newcomer to have previously held a high ranking position with his genomic figures. This calving ease sire (1.5 direct CE) is expected to transmit long daughter lifespans (+174 days), a high HealthyCow Index (275) as well as a good score for Feed Advantage (192).

Marco Winters, head of animal genetics for AHDB, says: “Each proven bull in this run of genetic evaluations began his journey as a young, genomically tested sire. This is a fitting endorsement of genomic technology which truly comes of age this year.”

The technology was introduced on a UK-wide basis when AHDB calculated the country’s first independent genomic indexes in April 2012.

“Since that time, leading genomic young sires have gone on to excel in the proven sire rankings, once their daughters have started to milk,” he says.

A table of the top 20 available Holstein bulls with a daughter proof ranked on the latest PLI (April 2022) is available on the AHDB website.

Rolling base

There’s a reminder this month that all genetic evaluations are now the subject of a rolling base. This means that the average animal against which all bulls are benchmarked now changes each year, in April, rather than every five years as was previously the case. The use of this ‘rolling base’ means there’s a slight drop in £PLI every year as the national average moves up. For 2022, Holstein females born in the UK between 2014 and 2017 are used as the average population, (or genetic base), such that any genetic index above zero (or below in the case of Maintenance, SCC and Mastitis Index) is better than average

Changes to the major genetic indexes this month

Minor changes to the £PLI formula have been introduced this April. These are designed to ensure the index keeps pace with economic conditions and the market outlook. They also take on board the UK’s changing cow population and advances in scientific knowledge.

The major changes for April 2022 are:

• The addition of Feed Advantage to the £PLI (only for Holsteins).
• The addition of a genetic index for Digital Dermatitis (DD) to £PLI for all breeds.
• DD is also added to the calculation of £SCI (Spring Calving Index) and £ACI (Autumn Calving Index).
• A change in formula for £SCI which more heavily penalises larger cattle for spring calving, grazing based systems.

Further details of these changes can be found on the AHDB website.