Sheep Recording can be separated into two main activities, data collection and data analysis.
1. Data collection
Data collection involves the breeder recording and submitting information about his
- Pre-mating. New flocks submit details of their breeding rams and ewes. Weights for homebred female shearlings can be submitted.
- Lambing. Lambing lists and diaries are sent to breeders. For each lamb, the breeder records it's identity, sex, date of birth, dam identity, dam age, sire identity and litter type (single, twin etc). Management practices such as embryo
transfer, fostering and artificial rearing are also recorded. Once the bulk of lambing has been completed these are sent for computer entry.
- 8 weeks post lambing. improvements can continue to be made as long as there is genetic variation
- 21 weeks post lambing. A list of all the lambs held on file is sent to the scanning operator who will then make an appointment with the breeder to weigh and scan lambs using ultrasound.
At each stage a series of validation checks is applied to retain the integrity of the database, ensuring the analyses undertaken are of the highest quality.
The standard measurements of performance are shown in Table 1. Recent research has generated a range of new traits, which are primarily being used amongst terminal sire breeders. These are presented in Table 2.
2. Data Analysis
A statistical procedure called BLUP, Best Linear Unbiased Predictor is used to estimate the breeding potential of every animal in the flock is used.
Each animal receives an analysis based on it's own performance, as well as that of its relatives and ancestors. The analysis takes into account the relationships between the animals, known relationships between recorded traits and the degree to which each trait is inherited by the next generation (heritability). The results produced by
the analysis are referred to as Estimated Breeding Values.