MORE than 60% of the UK's black and white dairy inseminations are now to genomic young sires, and with every one in the top 20 exceeding a Profitable Lifetime Index of £700, milk producers using such sires should see notable improvements in future generations.

That was the good news revealed in the latest genomic sire rankings by Marco Winters, head of animal genetics for AHDB who said there is now compelling evidence of the speed of genetic progress within the Holstein breed, with the new listings showing six new entries in the top 10.

“Young sires with figures like these are increasingly out-shining the proven sires which lag some way behind. We now have 120 £PLI points between the best young sires and the older, daughter-proven bulls," he said.

“Using a proportion of leading young sires will lift the genetic level of any dairy herd, although producers may find prices of some of the headline bulls to be prohibitive. However, they can find more than 40 young bulls which exceed the £PLI of the No 1 daughter-proven bull."

New headline bull for this December run from the previous August proof, is Westcoast Perseus, an early son of Penmanship, which himself held the No 1 position from December 2014, for 16 months.

Perseus is bred from a Doorman dam, and features high percentages of fat and protein (+0.12% and +0.10% respectively), combined with a good Lifespan Index (+0.6) and a high daughter Fertility Index (+10.5). With a PLI of £779 and a Type Merit (TM) of +2.37, this all-rounder is aged just 12 months, while his sire – which still features in the top 30 young sires of the breed – is not yet three years old!

The second ranking young sire is also new to the £PLI list, and the highest ranking of no fewer than nine top 20 sons of Cogent Supershot – a bull which came to the UK with a fanfare in 2013. This No 2 £PLI bull is Bomaz AltaTopshot, a transmitter of high production with a noteworthy +41.8kg fat. Out of an AltaEmbassy dam, he has a PLI of £762.

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). His breeder’s prefix features three times amongst the top 12 bulls.

Fourth position is taken by De-Su 13181 Quantum, another Supershot son – this one transmitting the highest weight of protein in the top 20 at +33.9kg. His dam is by Mogul and his PLI is £753.

The third Supershot son features in fifth, in the shape of Endco Superhero, whose good Lifespan Index (+0.7) contributes to a PLI of £737. Out of a Numero Uno daughter, he is another high type transmitter (TM +2.86).

Further new entries in sixth and seventh place are Peak AltaRecoil (AltaSpring x Jacey) and ABS Mayday (Tailor x Balisto). AltaRecoil has a PLI of £734 and a Fertility Index of +12.9 while Mayday transmits high milk quality (+0.14% fat and +0.09% protein), and has a good TB Advantage (+3.7). His PLI is £729.

Eighth position (PLI £723) is shared by the highest type transmitter in the top 20 (TM +3.11) in S-S-I 1stClass Flagship (Alta1stClass x Supersire), and the highest milk transmitter, DG Charley (Supershot x Mogul). Charley combines 968kg milk with good daughter longevity (Lifespan Index +0.7).

Rounding off the top 10 is Progenesis Unicorn (AltaSpring x Tango) which has the highest daughter Fertility Index in the top 20 at +14.8, meaning his daughters are predicted to have a calving index about nine days shorter than the average Holstein sire on the market.

While such sires should improve productivity, Mr Winters was never the less keen to careful selection.

“As has long been the case, I would recommend carefully selecting a cross-section of high £PLI proven and genomic bloodlines to suit your herd, but taking great care to avoid inbreeding by maintaining genetic diversity.

“The Inbreeding Checker launched by AHDB Dairy earlier this year will help identify bulls with outcross pedigrees in relation to a farmer’s own cows and any matings which result in high inbreeding levels are best avoided,” he said.