Page 91 - Hereford Magazine 2022

The case for

genotyping females

There is a tendency among beef producers to 3. Genomics
concentrate on the male side of the pedigree As NZ Herefords has Single-Step Breedplan, genomic
even though females contribute 50% of the information contributes to the EBVs of both male and female
genetics of their offspring. Individual bulls animals. This should encourage producers to genotype their
heifer drop to ensure they have the most accurate EBVs
typically have a bigger influence on the herd possible before replacement selection decisions are made. This
than individual cows, simply because they can be beneficial as these young heifers typically have limited
produce more progeny, but females also play a performance data and thus low EBV accuracy at this age [see
role in the herd’s genetic improvement. page 55, Explaining accuracy percentages]. Alternatively,
producers may wish to genotype a subset of females, such as
Words: Southern Beef Technology Services (SBTS) and Posy high genetic merit females, or genotype animals likely to be
Moody. Photos: Kate Taylor/Ella McWilliam. in single animal contemporary groups or small contemporary
groups (e.g. embryo transplant (ET) calves, show animals, or
animals from a small herd).
WHY GENOTYPE FEMALES?
Often there is more than a single reason for genotyping
Just as there are a number of reasons to genotype male an animal. Beef producers may decide to genotype female
animals, there are a number of reasons why beef producers animals for a combination of the reasons described above, e.g.
may consider genotyping their female herd. These include: for parentage verification, genetic condition management,
and genomics purposes. That’s why NZ Herefords offers DNA
1. Parentage verification ‘bundles’ to members so they can select to genotype animals
This could be for parentage verification of the female animal for a variety of purposes in one test. Bundles are also cheaper
and/or parentage verification of her future calves. While it than doing multiple individual tests.
currently is not compulsory for full parentage verification
(i.e. both the sire and dam) for female animals unless they
are being imported/exported, some producers may wish to WHICH FEMALES SHOULD I GENOTYPE?
parent verify their animals to have more certainty regarding
their pedigrees. Sire verification is also required for transfer. Deciding which females to genotype will vary from herd to
Unfortunately, experience has shown parentage errors can herd, and will depend on the motivation for genotyping. For
still occur even in the best-managed herds. Possible reasons producers who are keen to do full parentage verification, all
include multi-sire mating, rogue bulls, uncertainty as to dams of the calves they wish to do parent verification on will
whether the AI bull or the back-up bull is the sire, mis- need to be genotyped. This could be for all calves in a calving
mothering and/or human error. year, or a select subset (e.g. sale bulls only). Producers who
are managing genetic conditions – hypotrichosis, diluter,
2. Management of genetic conditions idiopathic epilepsy, maple syrup urine disease – may wish to
Beef producers may wish to genotype female animals to genotype cows from certain lines that contain known carriers.
understand their genetic condition status and/or qualitative The animals a producer wishes to genotype for genomics
trait status (e.g. horn/poll status). For producers who wish purposes may also vary from a subset of females through to
to know the genetic condition status of their females (for all heifers in the calving drop.
example, to avoid carrier-to-carrier mating if using a carrier
bull), genotyping select females may be of interest.

Year 2022 HEREFORD MAGAZINE 89