21 July 1995

Canadian lists put in doubt as Prelude topples

By Sue Rider

THE reliability of the Canadian bull proving system took a severe knock last week when its flagship bull Prelude fell from pole position of the Canadian lifetime profitability rankings (LPI).

The high-priced bull, who has been used widely as a sire of sons in breeding programmes throughout the world, and has had over 300 sons going into Canadian AI centres over the last two years, nosedived on LPI with the addition of over a thousand second-crop daughters to his production proof.

His Canadian figures (breed class averages) show that at 77% reliability in July 1994, he boasted an LPI of 2118. That figure has since dropped over 1000 LPI points to 1116 in the lastest evaluation run, despite his 80% reliability.

Preludes BCA for milk has fallen from +18 to +11, for protein from +19 to +11 and for fat from +27 to +22. His final class score for type has fallen from +18 points to just +5.

His UK conversion at 80% reliability now shows 661kg milk, 29kg (+0.07%) fat, 16kg (-0.06%) protein, and £61 PIN.

Semex believes that exceptional circumstances are responsible for Preludes poor performance.

It cites the average age of second-crop daughters at calving at just 23.5 months compared with an average of 28 months for first crop. Also that 85% of the second crop daughter records added this July were based on records in progress, with average days in milk at 141. By comparison, it claims, only 18% of Preludes January 95 proof was based on incomplete lactation records and the average record length was 305 days.

Average age

Fall in type is attributed to the average age of 27.4 months at classification of the bulls 1149 second crop daughters.

This compares with age of first crop daughters of 35.5 months at classification. "His daughters have not been given the chance to grow frame," says Semex geneticist Jo Bellamy.

She says the early calving Prelude daughters fail to show the strength and fore udder attachment rewarded by the final class type system.

The company is confident Preludes proof will return to a level that reflects his initial proof more closely and is still marketing the bull at £120 a straw.