Page 43 - Tapiri Angus 2021 Catalogue ebook

INDEX DESCRIPTIONS Self Replacing Index (SRI)
The following three graphs reflects the relative change if the New Zealand Genetic Selection of bulls using only the SRI tool will on average over
Angus Published Sires (at the Mid-August 2020 TransTasman Angus Cattle time develop a cow herd with the following:
Evaluation) were ranked on this selection index and the top 10% were used
within a breeding program. Given that the Published Sires are the sires of • Improved weaning rate through increased fertility
the next generation(s) of New Zealand Angus cattle and have more highly and easier calving
accurate EBVs (due to having progeny) than the average animal in the • A slowly decreasing cow size, milk and slowly increasing
database, these graphs represent the approximate selection response one body condition
would expect to see in the breed from using this index.
• Progeny will be prime at a younger age for slaughter
New Zealand Angus Self-Replacing Index - Predicted Response These characteristics are ideal for an environment where the herd is
exposed to prolonged seasonal feed deficits and feeding supplement
is unlikely.
Expected Change in Individual Traits

CEd CEm GL BW 200W 400W 600W MCW Milk SS DC Cwt EMA Rib Rump RBY IMF
Above the 0 line (X axis) selects for more positive numbers and below the line selects
for more negative numbers. For some traits (e.g. growth), a positive response is
desirable and for others (e.g. days to calving), a negative response is desirable.