A FATHER and son duo are the top two Holstein bulls in the proven sire rankings for the first time in recent memory, according to the new genetic index figures published this week.

In pole position and remaining the long-standing leader, ranked on Profitable Lifetime Index (£PLI) is Kings-Ransom Erdman (PLI £659), with his son, United-Pride Erdman Evan (PLI £647), standing in second.

Noted for transmitting outstanding fitness, Erdman boasts a breed-leading Lifespan Index of +0.9, with his daughters producing milk for almost a full lactation longer than those of an average sire. He combines this with good daughter fertility (Fertility Index +12.5) and Maintenance Index of -23, indicating his daughters cost less to feed for maintenance than those by other Holstein bulls.

Second-ranking Evan moves up from sixth position in the previous index run, thanks to 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. At present, this bull is not available in mainland GB, only being marketed in Northern Ireland.

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

The Bookem son, De-Su Rookie 11057 maintains his fourth position with a PLI of £625, good transmission of low cell counts and one of the higher Type Merits in the top 10 at +1.74.

Fifth ranking Tollenaars AltaMicro is the biggest improver of daughter fertility (FI +17.8) and has a PLI of £623, just ahead of the calving ease sire, Teemar Shamrock Alphabet (PLI £621).

The high reliability Holstein, Gen-I-Beq Lavaman ranks sixth, now with 647 UK daughters contributing to his figures and raising his PLI to £618. Lavaman’s index is noted for its high TB Advantage (+3.4), indicating his daughters have a higher resistance to bovine TB than other cows of the breed.

Moving into the top 10 is the well-known production superstar, Seagull-Bay Supersire, transmitting 1049kg milk and 74kg fat plus protein – by far the highest in the top 100 – earning him a PLI of £615.

Also moving up to the top 10 are the highest type transmitter, S-S-I Bookem Morgan (TM +1.89) and the third Robust son, Co-op Robust Jitterbug. They have PLIs of £598 and £589 respectively.

Commenting on the figures, Marco Winters, head of animal genetics for AHDB Dairy says: “It is positive to see so many sires which transmit such high daughter fertility and extreme longevity. The Holstein breed has suffered in the past when it was more difficult to identify these traits in bulls, but it’s encouraging to see there has been a rapid turnaround in the type of available sires.

“I would urge Holstein breeders to seek out these great fertility and lifespan transmitters, and to look for bulls with a minus maintenance cost. This way they will breed the most efficient cows which are easy to manage, fertile and fit.”