17 November 1995

Sorting out best of

breeds

BERRY Test, near Bourges in central France, is the centre for the national ram progeny testing programme. Eleven breeds are examined for meat-producing ability.

Berry is an integral part of breed selection programmes and every year receives semen from the best 10 rams from each breed. The rams have already been selected for reproductive performance and development, growth rate, conformation and breed characteristics.

The Berry ewe flock comprises 1000 Berrichon x Romanov ewes and 250 Romanov ewes. The smaller flock is inseminated by Berrichon du Cher rams to provide replacements for the larger flock.

Rams are allocated 25 ewes, either cervically inseminated with fresh semen or undergo laparascopic AI if frozen semen is used.

At lambing fertility and prolificacy is calculated for each ram by recording the number of lambs born to each ewe and her success rate to first service.

Other data includes method of birth, sex, rearing system and birth weight.

Lambs are weighed after 50 days (at weaning), at 64 days and again when they leave for the abattoir, the figures going to produce daily liveweight gain performance.

Slaughter, at 110 days, occurs at a constant weight for each breed, with a 6kg gap between sexes. Ten carcasses a ram are then analysed and measurements taken (see box).

All the data is checked at Berry and then sent to the National Institute of Agricultural Research (INRA). There it is corrected for effects of sex, method of lambing and rearing to produce an index.

The results are sent back to each breed society, which then classifies the rams on stricter parameters to produce a spider graph (see diagram) to visually describe each rams index.

"Berry Test provides a basis for national policy on genetic improvement," explains Jean-Claude Brunel, the centres director. "The facility enables new techniques to be studied and put into practice. For example, the use of ultrasound in fattening methods and on meat quality. Both of these traits may well need to develop in response to changing consumer tastes."


&#8226 Cold deadweight.

&#8226 Internal fat.

&#8226 Quality, quantity and extent of external fat.

&#8226 Thickness back fat.

&#8226 Carcass length.

&#8226 Hip width.

&#8226 Diameter shin bone.

&#8226 Conformation.

Each "compass" poin tis an estimate of the genetic value of the ram, expressed as a standard unit; average sires are given 10 points, 20 and 0 are equivalent to plus or minus three units in relation to the average. When the variables, age at slaughter, fat thickness and area of fat are unfavourable the relationship is reversed.