Page 92 - Hereford Magazine 2022

Year One Year Two Year Three Year Four
1 year old heifers 1 year old heifers 1 year old heifers 1 year old heifers
2 year old heifers 2 year old heifers 2 year old heifers 2 year old heifers
3 year old cows 3 year old cows 3 year old cows 3 year old cows
4 year old cows 4 year old cows 4 year old cows 4 year old cows
5 year old cows 5 year old cows 5 year old cows 5 year old cows
6 year old cows 6 year old cows 6 year old cows 6 year old cows
7 year old cows 7 year old cows 7 year old cows 7 year old cows

Years Eight and Beyond Years Seven Year Six Year Five
1 year old heifers 1 year old heifers 1 year old heifers 1 year old heifers
2 year old heifers 2 year old heifers 2 year old heifers 2 year old heifers
3 year old cows 3 year old cows 3 year old cows 3 year old cows
4 year old cows 4 year old cows 4 year old cows 4 year old cows
5 year old cows 5 year old cows 5 year old cows 5 year old cows
6 year old cows 6 year old cows 6 year old cows 6 year old cows
7 year old cows 7 year old cows 7 year old cows 7 year old cows

Figure 1. Genotyping one-year-old replacement heifers each year will allow beef producers to eventually reach the point
where all females in the herd have genotypes. Animals genotyped in the current year are highlighted in red, while those that
already have genotypes are highlighted in blue.

STRATEGIES TO GENOTYPE THE WHOLE
FEMALE HERD

Some breeders may be interested in genotyping all of
the females in their herds. However, for many, the cost
of genotyping all females in the herd in one hit can be
prohibitive. Using 2021 prices, the cost to genotype an animal
using the Hereford bundle (100K SNP panel) is $54, meaning
an outlay of $10,800 would be needed to genotype a herd
of 200 cows. An alternative strategy for beef producers to
consider is genotyping their replacement heifers each year.
It will take longer to reach the point where all females in
the herd have genotypes, but the total cost is spread across
subsequent years.

An example of this strategy is shown in Figure 1. In this
herd, cows are cast for age at eight years. In year one, the one-
year-old heifers are genotyped, while the remaining females
(two to seven years old) do not have genotypes. In year two,
the one-year-olds are genotyped, the two-year-olds already
have genotypes (having been genotyped in year one), while
the remaining females (three to seven) do not have genotypes.
This cycle repeats.

How long this takes to achieve depends on the age of the CONCLUSION
cows in the breeding herd, and which age group of cows is
genotyped each year. For example, if cows are not cast for There are several reasons why beef producers may wish to
age until 10 years old, it will take longer to reach the point genotype their female herd, including parentage verification,
where all cows are genotyped. No matter how many years management of genetic conditions and/or qualitative traits,
it takes to reach the point where all cows are genotyped, it and for genomic purposes. However, for many, the costs of
is recommended producers start with the youngest heifers genotyping the whole female herd at once can be prohibitive.
first. As the heifers are likely to remain in the herd for the Beef producers who wish to genotype their breeding females
longest time period of all the females, producers will be able may wish to consider doing so over multiple years, by
to utilise their genotypes (e.g. to parent verify their calves) genotyping the heifer portion of the herd each year until all
over subsequent years. From a genomics viewpoint, younger females have genotypes. While slower to reach the point where
animals are also likely to benefit the most from the inclusion all females in the herd have genotypes, this strategy has the
of genomics information in the calculation of their EBVs. advantage of spreading the cost over subsequent years.

90 HEREFORD MAGAZINE Year 2022