Page 11 - Koanui Herefords Catalogue ebook

Carcase EBVs
CW - Carcase Weight EBV (kg) estimates the genetic difference in carcase weight at a
standard age of 650 days. More positive EBVs indicate heavier carcases at 650 days of age.
EMA - Eye Muscle Area EBV (cm2) estimates genetic differences in eye muscle area at the
12/13th rib site of a 300kg dressed carcase. More positive EBVs indicate better muscling on
animals.
RIB - Rib Fat EBV (mm) estimates the genetic differences in fat depth at the 12/13th rib in
a 300kg dressed carcase. More positive EBVs indicate more subcutaneous fat and earlier
maturity.
RUMP - Rump Fat EBV (mm) estimates the genetic differences in fat depth at the P8 site on
a 300kg dressed carcase. More positive EBVs indicate more subcutaneous fat and earlier
maturity. Two fat EBVs are listed as there is variation between animals regarding fat depth at
the two sites.
RBY – Retail Beef Yield % EBVs are estimates of genetic differences between animals in
boned out retail beef yield in a standard weight steer carcase. RBY EBVs are reported as
differences in percentage (%) yield. Larger, more positive, RBY EBVs are generally more
favourable.
IMF - Intramuscular Fat % EBVs are estimates of generic difference between animals in
intramuscular fat (marbling) at the 12/13 rib site in a 300kg carcase. Larger, more positive,
IMF EBVs are generally more favourable.
$ Index Values
$ Index Values
Note there has been a change in the calculation of New Zealand Hereford Selection Indexes
this year. A selection index combines the EBVs with economic information (costs and
returns) for specific market and production systems to rank animals based on relative profit
values.
Hereford Prime Index - Estimates the genetic differences between animals in net
profitability per mixed age cow joined for a typical self-replacing commercial herd. Heifers
are retained for breeding and so maternal traits are of importance. Steers target 550 kg live
weight (300 kg carcase weight & 7 mm P8 fat) at 20 months of age, and heifers 475 kg (260
kg carcase weight & 8 mm fat depth), at 22 months of age.
Beef Heifer Index - Estimates the genetic differences between animals in net profitability
per yearling heifer joined for a typical self-replacing commercial herd. Steers target 510 kg
live weight (280 kg HSCW and 7 mm P8 fat depth) and heifers 450 kg ( 250 kg HSCW and 8
mm P8 fat depth) at 20 months of age.
Dairy Beef Index - Estimates the genetic differences between animals in net profitability
per mixed age dairy cow joined with all progeny destined for slaughter. Steers and heifer
progeny target 550 kg live weight (300 kg carcase weight and 6 mm fat depth) at 24
months of age and at 475 kg live weight (260 kg carcase weight and 7 mm fat depth) at 22
months, respectively.

NZ HEREFORD Breed Average EBVs for 2019 Born Calves
CARCASE EBVs $ INDEX VALUES
CW EMA RIB RUMP RBY IMF HPrime Beef Heifer Dairy Beef
+52 +3.5 +0.7 +0.8 +0.8 +0.5 +110 +112 +105 9