Introduction
Routine genetic evaluations and estimation of BLUP breeding
values are available for all the major sheep and goat breeds. New EBV’s are
calculated on a weekly basis or as needed when new data has been recorded.
Traits evaluated
Traits recorded for all the breeds included pre-weaning or
weaning weight, post weaning weight, fleece weight and fleece traits. Weaning
weight is used to calculate Total Weight of lamb Weaned per ewe per year (TWW).
EBV’s are calculated using multiple trait analysis. For reproduction traits a
repeatability model is used. Due to lack of linkage between flocks and other
constraints, EBV’s are not available for all breeds. The breeds and traits for
which EBV’s are available are as follows:
Mutton Breeds (Dorper, Dormer, Ile de France, Landskaap, Boer Goat)
- Birth weight - Direct and Maternal
- Weaning weight - Direct and Maternal
- Post weaning weight
- TWW
Wool Breeds (Dohne Merino, Merino)
- Yearling body weight
- Clean fleece weight
- Mean fibre diameter
- Staple length (Merino only)
- TWW (Merino only)
Output
For the mutton breeds these EBV’s are combined into a Rand
value which reflects Gross Margin Income per Small Stock Unit (SSU) per year.
Two additional Rand value rankings are also available namely a Sire Line (with
emphasis on growth traits) and a Dam Line (with emphasis on maternal traits and
reproduction).
For the wool breeds a selection index is also available. This
index is also expressed as a Rand value depicting gross margin per SSU per year.
For the Merino breed an additional Rand value index is available which also
includes TWW as a trait.
In addition a list of performance of sires used per
flock is available. Graphical displays of genetic trends against the breed are
also available. For each breed a National Sire list, ranked on Rand values is
supplied. These sire ratings are available on request.
Flock Profiles, own sire list and national sire ratings are
available as hard copies or in electronic format (csv-files).
Current investigations
- Recalculation of Rand value index for mutton breeds
- Incorporation of subjective assessed traits for Merino’s
- Incorporation of weaning weight traits into national evaluations of Merino’s
- Investigations into calculation of longevity for the different breeds
- On-going research on methodology used to calculate reproduction traits
(repeatability vs. multiple trait models)
- Variance estimations for growth and reproduction traits of SA Mutton
Merino’s with aim to include in National breed evaluation.
For Animal Enquiries click HERE
_________________________________________________________
<<< Back to Animal Recording and Improvement
