An initial round of culling occurs at marking based on excess wrinkle or hair, pigmentation or abnormalities of feet or eyes etc.
About 2 months after shearing, yearling ASBVs are reviewed and rams performing very poorly for a key individual trait or poorly for a number of traits are culled without even looking at the rams (so as not to be biased by any pretty wool). Traits used are fibre diameter, clean fleece weight, staple length, staple strength, worm egg count and body weight.
Remaining rams are then classed visually and culled on wool colour, wool character, back and shoulders, feet and legs, face cover and wrinkle.
At this point, there are no rams remaining with individual faults worthy of culling.
Rams are now reviewed for the combination of performance, wool style and conformation. Those that are average in a few things are now culled.
We now select our stud rams and reserves and then rams for our on-property sale.
Our own replacement rams are chosen on the combination of performance, wool style and conformation as well as lambing ease and pedigrees to avoid inbreeding. We almost only use polls or half polls in our transition away from horned sheep. We do not discriminate on whether they have scurs or half horns, as these are still a half poll genotype. Using only polls limits our choice of rams too much, even in semen sires.
Angus Carter, Landmark, assists in our sale ram selection.
What we directly measure or score
All characteristics followed by the word score are done using the standard from the Sheep Genetics Visual Sheep Scores guide.
- Date of birth
- Pedigree (both sire and dam)
- Birth weight
- Lambing ease
- Birth status (single, twin, triplet)
- Rearing status (raised as single, twin, triplet)
- Skin wrinkle
- Birth coat
- Other abnormalities
- Breech wrinkle score
- Breech cover score
- Other abnormalities
At this stage male lambs that are excessively wrinkled, very hairy, pigmented or have had other problems are castrated.
At 10 months (prior to first shearing)
- Face cover score
- Skin pigmentation score
- Wool pigmentation score
- Fleece rot score
- Wool colour score
- Wool character score
- Staple structure score
- Quality count
- Dag (this may be done at other times depending on feed and level of dag)
At shearing (10 months)
- mid side sample taken for
- Fibre diameter (plus SD, CV, curvature)
- Staple strength
- Staple length
- Greasy fleece weight (excluding bellies)
- Wool pigmentation (if not seen previously)
At ram selection (12-15 months)
- Body weight
- Review of other scores