Page 6 - Catalogue Omagh 2023 Final web file

UNDERSTANDING SIL INFORMATION

SIL (Sheep Improvement Ltd) is the New Zealand sheep industry’s
performance recording and genetic evaluation database. SIL estimated
breeding value (eBV) and selection index information is provided in some
sale catalogue listings. These assist ram selection by giving the best
estimate of genetic merit available.

INTRODUCTION TO SIL conjunction with SIL figures to

Performance and physical assess whether an animal will
appearance of animals are the perform well as a sire and will
result of a combination of factors; produce productive progeny.
the genes they get from their
parents, management such as SIL terminology can look confusing
feeding, and other effects such if you are not used to it. The
as age and rearing rank. To make following explanations of common
genetic improvement we need to terms and variables can be used to
be able to assess how much of an interpret SIL data with reference to
animal’s performance is controlled your breeding goals.
by the genes alone, as it is only the
genetic component of performance KEY DEFINITIONS
that is passed on to the next Estimated Breeding value (eBV):
generation. Visual assessment of Breeding values are the best
animals - or even assessment on estimate of the animal’s genetic
an individual animal’s performance value as a parent for traits. They
- can be a poor guide to the genetic allow rams to be compared with
merit of the animal. all rams included in the same

SIL measures of genetic merit do analysis. This may mean all rams
not tell us everything about an from the same flock or all animals
animal. For example, in order to in an across-flock evaluation where
function as a sire, a ram has to be there are strong genetic links
physically sound. Visual inspection between the different flocks (see
of soundness should be used in “Interpretation” below).

6 - OMAGH ANNUAL RAM SALE