Top Holstein Bull Still Top After Proof Re-Rank
19/08/08

Ongoing improvements to the way in which genetic indexes are calculated has produced a slight re-ranking of bulls in the newly published August proofs (published August 19, 2008). But the top three bulls from the previous proof run can still be found in the first four positions of this new ranking.

An O-Bee Manfred Justice daughter

“The Test Day Model – the method used for the calculation of genetic indexes – is being refined all of the time,” explains Marco Winters, director of DairyCo breeding+ who publish the figures. “On this occasion, a substantial increase in available computing power has enabled us to include all fourth and fifth lactation information for bull daughters and ancestors into the calculation – that’s 20 million extra lactations.

“Together with other improvements in accuracy – stemming from better adjustments for environmental effects such as season and age group – we now have more accurate figures than ever before.”

The result of the changes is a small average reduction of -0.05 percent fat and 13 points PLI (Profitable Lifetime Index) amongst Holstein bulls, although some bulls have inevitably bucked this trend.

The first bull to do so is the remarkable O-Bee Manfred Justice, a bull which continues to impress and now takes his most commanding lead ever with a massive 265 PLI points.

The first newcomer to the top 10 – moving up from number 13 last April - is the second-placed Laudan, another second crop bull and the first of two Lukas sons to feature in the top 10.

Numbers two and three from the last proof run – Mascol and Wizzard - now rank in third and fourth positions with minimal changes to their figures, while fifth position is taken by Leif, the second Lukas son. The proof of this older second-crop bull confirms him as a fitness specialist with outstanding cell count, lifespan and daughter fertility indexes.

Highest ranking of the UK progeny tested bulls is Huddlestone Spooky - bred out of a full sister to Mascol and with a PLI of 190.

Other noteworthy bulls in the top 20 and all with an impressive 175 PLI points or more are the daughter fertility specialists Delta Peridot (Fertility Index +5.1) and Klassic Merrill Lynch (FI +7.0).

The top daughter lifespan transmitters are Ramos and Gibor with Lifespan Indexes of +0.8 and +0.7 lactations respectively. And finally the top Type Merit bulls in the top 20 are Picston Shottle – now with almost 5,000 daughters contributing to his UK proof – who maintains an excellent Type Merit of +3.5; and Braedale Goldwyn, at a comparable +3.4.

Tom Peters Joins the Cogent Team
High Ranking Holstein Sexed Semen at Conventional Prices
Elizabeth Reigns Supreme in Holstein All-Britain Awards