Page 6 - Waiterenui 2020

BREEDPLAN www.waiterenui.co.nz

BREEDPLAN Traits Whilst EBVs provide the best basis for the comparison of the genetic
merit of animals reared in different environments and management
UNDERSTANDING THE EBVS conditions, they can only be used to compare animals analysed
An animal’s breeding value is its genetic merit, half of which will be within the same analysis. Consequently, NZ ANGUS BREEDPLAN
passed on to its progeny. While we will never know the exact breeding EBVs cannot be validly compared with EBVs for any other breed.
value, for performance traits it is possible to make good estimates. Although EBVs provide an estimate of an animal’s genetic merit for
These estimates are called Estimated Breeding Values (EBVs). a range of production traits, they do not provide information for all
In the calculation of EBVs, the performance of individual animals of the traits that must be considered during selection of functional
within a contemporary group is directly compared to the average animals. In all situations, EBVs should be used in conjunction with
of other animals in that group. A contemporary group consists of visual assessment for other traits of importance (such as structural
animals of the same sex and age class within a herd, run under soundness, temperament, fertility etc). A recommended practice is to
the same management conditions and treated equally. Indirect firstly select breeding stock based on EBVs and to then select from
comparisons are made between animals reared in different this group to ensure that the final selections are otherwise acceptable.
contemporary groups, through the use of pedigree links between EBVs are published for a range of traits covering fertility, calving
the groups. ease, milking ability, growth, carcase merit and feed efficiency. When
EBVs are expressed in the units of measurement for each particular using EBVs to assist in selection decisions it is important to achieve a
trait. They are shown as + ive or - ive differences between an balance between the different groups of traits and to place emphasis
individual animal’s genetics difference and the genetic base to which on those traits that are important to the particular herd, markets
the animal is compared. For example, a bull with an EBV of +50 kg and environment. One of the advantages of having a comprehensive
for 600-Day Weight is estimated to have genetic merit 50 kg above range of EBVs is that it is possible to avoid extremes in particular
the breed base of 0 kg. Since the breed base is set to an historical traits and select for animals with balanced overall performance.
benchmark, the average EBVs of animals in each year drop has CALVING EASE EBVS (%) are based on calving difficulty scores, birth
changed over time as a result of genetic progress within the breed. weights and gestation length information. More positive EBVs are
The absolute value of any EBV is not critical, but rather the favourable and indicate easier calving.
differences in EBVs between animals. Particular animals should be CE % DIRECT = DIRECT CALVING EASE - The EBV for direct calving ease
viewed as being “above or below breed average” for a particular trait. indicates the influence of the sire on calving ease in purebred
females calving at two years of age.

P age 4 | W aiterenui Angus | Passion Per formance Profit