THERE is more variation in bloodlines compared to recent years in the latest young Holstein sire genomic index published by AHDB dairy this month.

Taking the top spot is Mr Rubi-Agronaut, a bull offering different genetics from the usual with Rubicon, Shotglass, Shamrock and KHW Goldwyn Aiko all featuring in his pedigree. He transmits high components (+0.18% BF and +0.08% P) as well as good daughter health and fertility, and comes with a profitable lifetime index (£PLI) of £793. He is further boosted with 2.53 for type merit (TM), the highest in the top 10. 

The former number one, Westcoast Perseus, is now in second and remains the highest ranking Penmanship son. With a PLI of £784, he continues to pass on high production with good milk solids and daughter health and fertility. 

Westcoast Guarantee, also from the Canadian herd formed in 2010, follows on with a PLI of £782. Sired by the young Supersire son, Bryceholme SS Boastful, Guarantee as one of the best scores among the top bulls for the new mastitis predicted transmitting ability (PTA), which sits at -5. He also transmits a good combination of high milk volume and solids with very low cell counts (SCC index -29).

In fourth position is another newcomer and the third Canadian-born bull in the top five, Progenesis Padawan. Another bull transmitting high milk volumes and weight of fat and protein, Padawan also excels for daughter fertility (fertility index +15.1). This son of S-S-I Montross Jedi has a PLI of £761 and a TM of 2.51.

The first of the UK-bred bulls sits in fifth position as Prehen Lancaster, a Penmanship son bred by Northern Ireland’s Stuart Smith, earns himself a PLI of £759. Bred from a high index Shamrock daughter, Lancaster is an all rounder for production and fitness, and is the best improver of daughter fertility with an index of +16.9. He also boasts a low maintenance index of -2, one of the lowest in the top 10.

A son of the UK-owned Cogent Supershot, Bomaz AltaTopshot, sits in sixth with a PLI of £740, while Danish-bred VH Baliston Brook moves up to seventh thanks to his PLI of £737. Balisto Brook also scores well for the new mastitis PTA at -5. 

With a PLI of £729, De-Su Curry 13360 makes his debut on the list in eighth position while ABS Mayday remains almost unchanged in ninth with a PLI of £728.

Sharing 10th with a PLI of £725 are US newcomer De-Su Maxfli 13243, and Danish-bred VH Balisto Brixton.