A NEW number one bull in the shape of the Morgan son, Mocon, has taken his place in the proven Holstein sire rankings, published this month by AHDB Dairy.

The German-bred Mocon is a maternal grandson of Snowman and his predicted transmitting ability (PTA) features high milk production (826kg), low somatic cell counts (-23) and a very favourable maintenance index (-22), indicating his daughters have relatively low maintenance costs for feed. He earns a profitable lifetime index (PLI) of £689.

In taking the number one position, Mocon edges long-term leader, Lavaman (PLI £684), into second position. Lavaman scores high for lameness advantage, one of the new indexes introduced this month (see panel). This positive score of +6.7 indicates 6.7% fewer Lavaman daughters are predicted to have lameness incidents than a bull with a score of 0.

Places three to seven are taken by bulls which have all featured previously in the top 10 and whose daughter performance continues to support their impressive indexes. In third position is S-S-I Shamrock Mystic (PLI £654) with a very high daughter fertility index (+19.8).

He is followed by the high (30.6kg) protein sire, De-Su 11236 Balisto, who now has 473 UK daughters contributing to his production figures. Balisto progeny also display greater TB resistance than their cohorts, indicated by his TB advantage of +3.3.

View-Home Littlerock ranks fifth (PLI £646), followed in joint sixth position by Teemar Shamrock Alphabet and VH Cole Clark (PLI £636). Both Alphabet and Clark have favourable Maintenance Indexes (-22), long daughter lifespans (LS +0.8) and good daughter fertility (FI +18.5 and +21.2 respectively).

New in eighth place is Larcrest Commend (PLI £633). This Balisto son has very good milk composite scores of +0.26% fat and +0.17% protein, and, despite milk volume being lower than his cohorts, he still transmits an impressive weight of fat, at 28.2kg.

Ninth ranking Co-op Robust Cabriolet (PLI £628) transmits the highest weight of fat in the top 10 £PLI sires at 38.9kg, together with good protein at 25.9kg. Cabriolet also features an impressive 4.8% improvement for the newly released calf survival index, another new index launched this month, with this score meaning 4.8% more of his daughters are expected to survive between tagging and 300 days than daughters of a bull with an index of 0.

rounding off the daughter-proven top 10 is another new entry, apina norman. this former number one genomic young sire also has the highest type merit of the top 10 £PLI sires at +2.15.

Outliers outside the top 10

OUTLIERS with something extra to offer which fall outside the top 10 include the impressive fat improver, EDG Rubicon at 44.8kg fat, which also brings a type merit of +3.08; the exceptional mastitis improver, De-Su Pocono (-5); and the high protein bull, S-S-I Montross Jedi (37.2kg).

Among the bulls with the lowest daughter maintenance costs are Mr Miguel and the former number one sire, Kings-Ransom Erdman, both with maintenance indexes of -28.

UK breeding

THOSE who favour UK-bred bulls, will find impressive performance from the newly proven Willsbro Atwork (PLI £580) and long-term favourite, Prehen Omen (PLI £553), both well within the top 50 sires.

“As in previous index runs, a selection of high health and fertility improvers with good production of milk solids dominate these rankings,” said geneticist, Marco Winters from AHDB Dairy.

“For breeders who prefer the reassurance of daughter-proven bulls, there is much to find in these rankings, with many bulls now offering reliability approaching or hitting 99%, including Lavaman and Balisto in the top 10.”