Page 11 - Sudeley Angus ebook

inherited from the sire, on the 200-day weights of her calves. For
dams, it indicates her milking ability.
Scrotal Size EBV (cm) is calculated from the circumference of
the scrotum taken between 300 and 700 days of age and adjusted
to 400 days of age. This EBV is an estimate of an animal’s genetic
merit for scrotal size. There is also a small negative correlation
with age of puberty in female progeny and therefore selection for
increased scrotal size will result in reduced age at calving of female
progeny.
Days to Calving EBV (days) indicates the fertility of the
daughters of the sire. It is the time interval between the day when
the female is first exposed to a bull in a paddock mating to the
day when she subsequently calves. A negative EBV for days to
calving indicates a shorter interval from bull-in date to calving
and therefore higher fertility.
Carcase Weight EBV (kg) is based on abattoir carcase records
and is an indicator of the genetic differences in carcase weight at
the standard age of 750 days.
Eye Muscle Area EBV (sq cm) is calculated from measurements
from live animal ultrasound scans and from abattoir carcase data,
adjusted to a standard 400 kg carcase. This EBV estimates genetic
differences in eye muscle area at the 12/13th rib site of a 400 kg
dressed carcase. More positive EBVs indicate better muscling on
animals. Sires with relatively higher EMA EBVs are expected to
produce better-muscled and higher percentage yielding progeny
at the same carcase weight than will sires with lower EMA EBVs.
Rib Fat and Rump Fat EBVs (mm) are calculated from
measurements of subcutaneous fat depth at the 12/13-rib site
and the P8 rump site (from live animal ultrasound scans and
from abattoir carcases) and are adjusted to a standard 400 kg
carcase. These EBVs are indicators of the genetic differences in
fat distribution on a standard 400 kg carcase. Sires with low, or
negative, fat EBVs are expected to produce leaner progeny at any
particular carcase weight than will sires with higher EBVs.
Retail Beef Yield EBV (%) indicates genetic differences between
animals for retail yield percentage in a standard 400 kg carcase.
Sires with larger EBVs are expected to produce progeny with
higher yielding carcases.
Intramuscular Fat EBV (%) is an estimate of the genetic
difference in the percentage of intramuscular fat at the 12/13th
rib site in a 400 kg carcase. Depending on market targets, larger
more positive values are generally more favourable.
Docility EBV (%) is an estimate of the genetic differences
between animals in temperament. Docility EBVs are expressed as
differences in the percentage of progeny that will be scored with
acceptable temperament (ie. either “docile” or “restless”).

SUDELEY GENETICS SHEEP & CATTLE COMPANY 11