Page 27 - Hauroko Valley Sale Catalogue eBook.pdf

WAIAU HEREFORD STUD

EBV’S Explained

CALVING EASE: DIR - Indicates how easily this bull’s progeny are likely to be born

DTRS - Indicates how easily this bull’s daughters are likely to calve.
More positive EBVs indicate easier calving.

BIRTH: BWT - 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 lower the likelihood of a
difficult birth. This is particularly important when selecting sires for use over heifers.
FERTILITY: SS - Scrotal Size (cm) is an indicator of male fertility in regards to semen
quality and quantity. Higher (positive) EBVs indicate higher fertility. SS is also positively associated
with female fertility.

GROWTH: Milk - 200-Day Milk EBV (kg) is an estimate of an animal’s milking ability.
For sires, this EBV is indicative of their daugthter’s milking ability as it affects the 200 day weight of
their calves.
200 - 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 - 400-Day Weight EBV (kg) is calculated from the weight of progeny taken between
301 and 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 - 600-Day Weight EBV (kg) is calculated from the weight of progeny taken between
501 and 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.

MV - Maternal Value EBV is an index of the EBVs for the 200-Day Growth and 200-Day Milk,
and is calculated by the following formulae: For sires: MV = 1/2 Milk EBV + 1/4 200-Day Growth
EBV. For dams: MV = Milk EBV + 1/2 200-Day Growth EBV.
MCW - Mature Cow Weight is an estimate of the genetic difference in cow weight between animals
at five years of age.MCW EBVs for sires are based on weights recorded on their daughters. Smaller
or more moderate MCW EBVs are generally more favourable as they indicate more efficient cows
requiring less feed for maintenance.

CARCASE: CWT - 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.

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