Page 13 - Puke-Nui Angus Catalogue eBook.pdf

• Progeny will be prime at heavy carcase weights where the improved
INDEX DESCRIPTIONS Self Replacing Index (SRI) AngusPure Index (API) marbling and subsequent eating quality traits can be expressed.
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 New Zealand Angus AngusPure Index - Predicted Response
Angus Published Sires (at the Mid-August 2020 TransTasman Angus Cattle time develop a cow herd with the following: These characteristics are ideal for an environment where the cow herd can
Evaluation) were ranked on this selection index and the top 10% were used be managed with extra feed if seasonal feed deficits occur.
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 Comparison of SRI and API
accurate EBVs (due to having progeny) than the average animal in the • A slowly decreasing cow size, milk and slowly increasing Expected Change in Individual Traits SRI is a maternal trait emphasised index.
database, these graphs represent the approximate selection response one body condition API is also a maternal driven index with added carcase trait emphasis.
would expect to see in the breed from using this index.
• Progeny will be prime at a younger age for slaughter
API selected animals can produce more net profit per animal through extra
New Zealand Angus Self-Replacing Index - Predicted Response These characteristics are ideal for an environment where the herd is CEd CEm GL BW 200W 400W 600W MCW Milk SS DC Cwt EMA Rib Rump RBY IMF performance when feed is abundant. Finished progeny can be taken to
exposed to prolonged seasonal feed deficits and feeding supplement Above the 0 line (X axis) selects for more positive numbers and below the line selects heavier weights with increased likelihood of achieving marbling premiums.
is unlikely.
Expected Change in Individual Traits Genetic Selection of bulls using only the API tool will on average over performance in environments where the cow herd is likely to be challenged
SRI selected animals can produce more net profit per animal through extra
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.
by regular seasonal feed deficits, maintaining body condition is critical to
longevity and feeding out is not a viable option.
time develop a cow herd with the following:
• Improved weaning rate through increased fertility and easier calving
CEd CEm GL BW 200W 400W 600W MCW Milk SS DC Cwt EMA Rib Rump RBY IMF • A slowly increasing cow weight/size, and milk production
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. 13