The leading young Holstein sires with genomic indexes show more variation in bloodlines than often in the past, with eight sires represented amongst the top 10 bulls.
At the top of the ranking, published this week (4 April, 2017) by AHDB Dairy, is Mr Rubi-Agronaut, a bull which has a different sire stack from many, with Rubicon x Shotglass x Shamrock x KHW Goldwyn Aiko in his back pedigree. Transmitting particularly high milk components (+0.18% fat and +0.08% protein) and good daughter health and fertility, Agronaut has a Profitable Lifetime Index of £793. He also offers 2.53 points for Type Merit, the highest score in the top 10. This is somewhat lower than we’ve become accustomed to seeing amongst the leading young sires, and reflects the slightly reduced scale on which Type Merit is now published.
Former number one sire, Westcoast Perseus is now in second place and is the highest ranking son of Penmanship. He continues to show the high production with good milk solids and daughter health and fertility of the previous index run and has a PLI of £784.
One position below Perseus is his herd-mate, Westcoast Guarantee (PLI £782), from the British Columbia-based herd which was founded in 2010. Transmitting an exceptional combination of high milk volume and solids with very low cell counts (SCC Index -29), Guarantee has one of the best scores for the new Mastitis PTA (Predicted Transmitting Ability) amongst the leading bulls at -5. His sire is Bryceholme SS Boastful, himself a young Supersire son.
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). A son of S-S-I Montross Jedi, he has a PLI of £761 and a Type Merit of 2.51.
The fifth ranking bull is the first from the UK, and comes in the shape of Prehen Lancaster. Bred by Stuart Smith in Northern Ireland, he is one of a succession of top bulls which hail from this herd. With an exceptional all-round index for production and fitness and as the best improver of daughter fertility in the top 10 (Fertility Index +16.9), Lancaster earns a PLI of £759. Also of note is this bull’s Maintenance Index, which, at -2, indicates his daughters will cost less to maintain than average, and less than most other bulls’ daughters in the PLI top 10. Lancaster is a son of Penmanship, and descends from the Laurie Sheik family. His dam, Prehen Shamrock Lady VG85 is a high index daughter of Shamrock and gave 9,755kg at 4.1% fat and 3.13% protein (305 days) as a heifer.
It’s back to North America for the number six bull and Bomaz AltaTopshot maintains the good position he held in the previous index run. A son of UK-owned Cogent Supershot, the outstanding feature of his good all-round transmission is his weight of fat (+40.8kg) and he earns a PLI of £740.
Seventh ranking VH Balisto Brook moves up the ranking, and is most notable for transmitting exceptionally low cell counts, with an SCC Index of -33, the best of the top 100 sires. Hailing from Denmark where there’s been a long-term focus on udder health, it is perhaps no surprise this son of Balisto also scores well for the new Mastitis PTA at -5. His PLI is £737.
De-Su Curry 13360 is a newcomer in eighth position, offering by far the highest volume of milk in the top 10 at 1,084kg, yet still remaining in positive territory for percentages of fat and protein. With a breed-leading 42.7kg fat and 38.6kg protein, he also offers 0% fat and 0.04% protein in his PTA. This son of high ranking genomic sire Jedi has a PLI of £729.
The index of ABS Mayday remains almost unchanged in ninth position, with a PLI of £728 while 10th position is shared by Danish and American bulls with notably different breeding patterns. Each with a PLI of £725, the US newcomer, De-Su Maxfli 13243, a son of an outcross sire Melarry Mack Alco, transmits 610kg milk and 65.4kg fat plus protein, together with solid performance in all other departments whereas Danish bred VH Balisto Brixton differs on many fronts. With just 8kg milk and a massive 0.34% fat and 0.22% protein he is bound to improve milk quality, while his Maintenance Index of -14 suggests his daughters will be cheap to maintain.
“Young genomic sires continue to impress in this April index run,” says Marco Winters, head of animal genetics for AHDB Dairy. “Farmers are using them with growing confidence and in increasing numbers, and it is no surprise that they now account for the majority of dairy inseminations.”