EBVs explained
An animal’s breeding value is its genetic merit, half of which will be passed on to its progeny.
FERTILITY AND BIRTH
Scrotal Size EBV (cm) is an indicator of male fertility in regard to semen quality and quantity in Western breeds of cattle.
Higher (positive) EBVs indicate higher fertility. There is also a small negative correlation (desirable) with age of puberty
and fertility in female progeny. The relationship between scrotal size and fertility in Wagyu is assumed, but not proven.
Gestation Length EBV (days) is based on Al records. Lower (negative) GL EBVs indicate shorter gestation lengths which
generally relate to lighter birth weights and easier calving.
Birth Weight EBV (kg) is based on the measured birth weight of animals, adjusted for dam age. The lower the value the
lighter the calf at birth and the lower the likelihood of a difficult birth. This is particularly important when selecting sires for use over heifers.
Growth
Milk EBV (kg) is an estimate of an animal’s milking ability. For sires, this EBV is indicative of their daughter’s milking ability
as it affects the 200-day weight of their calves.
200-Day Growth EBV (kg) is calculated from the weight of animals taken between 80 and 300 days of age. Values are
adjusted to 200 days and for dam age. This EBV is the best single estimate of an animal’s genetic merit for growth to
early ages.
400-Day Weight EBV (kg) is calculated from the weight of animals taken between 301and 500 days of age, adjusted to 400 days and for dam age. This EBV is the best single estimate of an animal’s genetic merit for yearling weight.
600-Day Weight EBV (kg) is calculated from the weight of animals taken between 501and 900 days of age, adjusted to 600 days and for dam age. This EBV is the best single estimate of an animal’s genetic merit for growth beyond yearling age.
Carcase EBVs explained
Carcase Weight EBV (kg)
is based on abattoir carcase records and live weight measurements (particularly 600 Day weight) and is an indicator of the genetic differences in carcase weight at the industry average slaughter age of 990 days. Larger positive values are more favourable.
Eye Muscle Area EBV (cm2)
estimates genetic differences in eye muscle area at the 12/13th rib site of a 420kg dressed carcase. A higher positive EBV indicates larger eye muscle area and therefore higher retail beef yields. Ultrasound, AusMeat and Japanese Digital Image Camera measured Eye Muscle Areas from slaughter animals contribute to this EBV.
Rump Fat EBV (mm)
estimates the genetic differences in fat depth at the PS site of a 420kg dressed carcase. A higher positive EBV indicates more subcutaneous fat and earlier maturity.
Retail Beef Yield % EBV
estimates the genetic differences in total (boned out) meat yield as a percentage of
a 420kg dressed carcase. A higher positive EBV indicates higher percentage yield for the 420kg carcase weight.
Marble Score EBV
(Aus-Meat Marble Score) is an estimate of the genetic difference in the Aus-Meat Marble Score in a
420kg carcase. Marble Score EBV utilises Aus-Meat Marble score on a scale of 1 to 10 where 10 is equivalent to an AusMeat Marble Score grading of 9+. Where results from the Meat Image Japan digital carcase camera are available, Camera
Marbling Percentage and Marble Fineness are also used to calculate Marble Score EBV as the genetic correlations
between these measures and Aus-Meat Marble Score are very high. Larger positive values are more favourable
Marble Fineness EBV
(Marbling Fineness Index) estimates the genetic differences in the Marbling Fineness Index
(degree of fineness of marbling fat) as measured by the Japanese Digital Image Camera. A higher more positive EBV
indicates higher levels of marbling fineness.
BREEDER FEEDER INDEX (BFI)
Introduced in 2024, the Breeder Feeder Index (BFI) is a balanced selection index designed to help Wagyu breeders select
the most profitable animals for a self-replacing herd while effectively managing birth weight, milk production, and mature
cow weight. The BFI estimates genetic differences between animals in terms of net profitability for cows joined, based on
the production of 435kg for steers and a 385kg carcase from heifers at 28 months of age. The BFI places the following
emphasis on key traits: 40% Marble Score, 19% Carcase Weight, 5% Eye Muscle Area, 12% Birth Weight, 6% 200-Day
Gain, and 8% Milk