Interbull upgrades way proofs are calculated

23 February 2001

Interbull upgrades way proofs are calculated

By Marianne Curtis

MANAT remains top Holstein bull available in the UK using the first official proof run based on Interbull evaluations rather than converted proofs.

This change in the way bull proofs are calculated should improve the accuracy of its published information, according to Animal Data Centre director Gordon Swanson.

"Conversions have been used for the last 30 years and overall, have served us well. But Interbull evaluations are superior and will provide more accurate information on international bulls."

Using the conversion system meant that although a bull may have had daughters in several different countries, data from daughters in only one country could be used to calculate his proof.

At least 20 countries supply data to Interbull which allows daughter information to be merged, producing a more accurate proof, according to Mr Swanson.

Using the Interbull system will bring particular improvements in the accuracy of type merit information, believes chief executive of Holstein UK and Ireland David Hewitt. "It uses data from all sources and has been well received by the industry."

However, with only one release of figures/quarter, the new proof system fails to highlight UK proven bulls.

Those featuring high in the February 2001 rankings include Cogents Joyce Mountain at 10 with a £PLI of 69, offering 726kg milk, 15.8kg fat and 27.5kg protein. The companys bull Principal has a £PLI of 66, an improvement of £6 since last November. His type merit has also increased from 1.7 to 1.98.

Receiving his first proof with UK daughters, Genus bull Ricecrest Brett ranks in 22nd position with a £PLI of 62 and costs £20/straw. Wa-Del Convincer, at £35/straw, appears at 27 with a £PLI of 61, offering a yield of 842kg at 23.6kg fat and 22.9kg protein. Convincers type merit is also strong at 1.8.

Genus dairy product manager, James Simpson says both Convincer and Brett have been used extensively as sires of sons within many international breeding programmes.

"With both sires having more than 100 daughters in milk in the USA, it is pleasing to see this reinforced in the UK."

Sires from Avoncroft retain a strong presence in the top 10 with Jesther improving on his £PLI by £6 to 77 since the November proof run. The companys Eastland Festival, with a £PLI of 76, offers high production at 1020kg milk.

With a £PLI of 72, Genus bull Ricecrest Lantz enters the top 10 for the first time, his ranking helped by the new proof calculation method, believes Mr Simpson. "His PLI has jumped by £14 since the last proof run and he may have been underestimated in the past. Lantz is strong on production, protein and type merit." &#42

Using Interbull to calculate proofs will increase accuracy, says Gordon Swanson.

Top 10 available Holstein bulls ranked on PLI(Feb 2001)

Manat 75 89 3.3 38 Dairy Daughters

Elite Mountain Donor 81 83 -0.2 22 Semen World

Ricecrest Marshall 71 83 2.0 30 Alta

Jesther 68 77 1.4 32 Avoncroft

Eastland Festival 79 76 – 19 Avoncroft

Delta Webster 67 75 1.9 25 Avoncroft

Lorak 76 73 1.6 25 Supersires

Ricecrest Lantz 72 72 1.9 32 Genus

Fatal 59 70 1.7 24 Supersires

Joyce Mountain 69 69 -0.8 18 Cogent