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Proven-sire performance matches genomic promise (Jan 23)

Two-time NMR/RABDF Gold Cup finalist and renowned pedigree breeder James Tomlinson shares his excitement about the latest daughter-proven sire list, and his disappointment with the genomic ranking.


Number-one sire: Bomaz Alta Cabot

The proven ranking is where it’s all at this time around, according to Lancashire-based producer and breeder James Tomlinson, and not least because he already has 10 daughters milking by number-one sire Bomaz AltaCabot.

This bull made his debut as a top-10 genomic sire four years ago and has now reached the number-one position in this month’s Profitable Lifetime Index (£PLI) ranking for daughter-proven sires, published in December by AHDB.

AltaCabot achieves this feat with 141 UK daughters contributing to his figures, alongside many more milking around the world. He earns a PLI of £765 and continues to demonstrate his early strengths of high fat production and a good Lameness Advantage (+2.6). He also gains a high score for the relatively recently launched Feed Advantage (+162), indicating the predicted feed efficiency of his daughters.

“We’re certainly impressed with the heifers we’re milking,” says James. “We used him as a genomic sire and we’re really pleased he’s come through. We still have some straws in the flask, and I’ll be buying some more. “He’s matched his genomic proof, and his heifers look after themselves, with exceptional SCC and fertility scores,” he adds.

AltaCabot descends from the same cow family as the former number-one sire, Bomaz Monument-P, who now ranks second with a PLI £745. Monument-P transmits even higher fat at 41.6kg, and shares the highest score with AltaCabot for another relatively new breeding index, EnviroCow. Both bulls score +3.6, reflecting the good environmental credentials expected of their daughters.

“I’ve not used him yet, but he’s on my ‘maybe’ list. He looks good, but his type merit of 0.14 is a little low for me,” says James. New entrant in third position, Pine-Tree CW Legacy (PLI £739), is a former number-one genomic sire whose availability has been limited in the past. However, Legacy now ranks with outstanding udder health indexes, (–29 SCC and –4 mastitis), and transmits long lifespans to his daughters (+174). The combination of great health, longevity and daughter fertility (+13.9) earns him one of the best HealthyCow ratings, at 328.

“Again, he’s a great sire. But it’s a ‘no’ for me due to his linear – it’s just a bit too extreme for my liking. The same can be said for the rest of the sires in the top 10. But that’s just my preference – they’re all cracking sires.” Holding on to his top-five ranking in fourth place is Hurtgenlea Richard Charl with the highest milk PTA in the top list (1,004kg) and a PLI of £736.

New in fifth place is Aurora Ragnar, a fresh graduate to the proven list who confirms his earlier genomic figures, transmitting good calf survival at 3.3 and earning a PLI of £735.

Staying power

Jumping to the sire in 16th place, Stowey Magician, is where the magic happens again for James. “He’s been in the top 20 for the past few bull-proof runs, so he’s got staying power. And even though his milk is 468kg – just below my personal lower limit of 500kg – he’s on my new-year wish list.“

He’s a UK sire, which always curries favour with me. He’s a good balanced bull with –11 for SCC, 16.7 for fertility and 1.15 for type merit. So I’ll be hoping to get my hands on some straws in 2023.”

James regrets to say he’s less enamoured with December’s young-sire ranking. “It’s not the first time it’s been disappointing for me, but that’s not to say that there aren’t some great sires on the list – they’re just too extreme for my liking and there are plenty of daughter-proven bulls to choose from instead.”

A brand-new number-one Holstein bull takes a convincing lead in this young genomic sire ranking. Wilra SSI Faneca Ebersol’s PLI of £1,017 demonstrates the impressive profit-earning potential of his daughters, its breakdown, including outstanding Predicted Transmitting Abilities (PTAs) for fat (56.4kg and +0.27%), udder health (–29 SCC, –3 Mastitis) and daughter fertility (Fertility Index +11.5), indicates the origin of much of their commercial advantage. But he, like the other top sires in this list, lacks the solid pedigrees and balanced linears that James looks for.

“They’re great sires and will certainly suit and meet other producers’ breeding goals, but they’re just not leaping out at me. I’m just being honest when I say that I can’t get excited about anything in the top 10.”

Genosource Captain’s PLI of £959 now earns him second position in the genomic list. His transmission of milk production remains among the highest in the breed, at 1,070kg PTA milk, which he combines with a high calf survival at 4.7.

Moving into third place is Denovo 17835 Lennon-P (PLI £955), one of the best bulls on the list for daughter longevity, transmitting an extra 162 days more lifespan than average. Also passing on excellent daughter fertility (FI +12.6), he has an outstanding HealthyCow index at 298.

Next up are three sons of long-time leader, Genosource Captain. In fourth place is DG Peace (PLI £949) who now ranks fourth, and like his sire, transmits high milk (1,080kg). However, he tops his sire for protein transmission, with a massive 41.5kg. DG Space is a new entry in fifth place with a PLI of £942. He’s an outstanding udder health improver (–27 SCC, –3 Mastitis) and a superb overall health transmitter (HealthyCow 301).

Sharing fifth place is UK-bred Cogent Keopon Rocky who also ranked in the top five in the August release.“There are a lot of good figures among these sires – really exceptional scores – but I’m after more,” says James, adding that there have been similarly disappointing bull-proof runs for him in the past.

Genomic sire: Cookiecutter Holysmokes

It’s not until he gets to Semex’s Cookiecutter Holysmokes, again sitting 16th in the ranking, that his interest is piqued. “He’s caught my eye, being from the Delia cow family and having a balanced linear. He ticks all my boxes, so I’ll be making enquiries. I looked at him before, but he was out of my price range. I think he may have come down a little and, if so, I’ll be getting a few straws for my flask.”

Table 1: Top 10 daughter-proven and top 10 genomic Holstein sires available in the UK, ranked on PLI (source: AHDB Dairy)

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