British Simmental Review 2023

TECHNICAL
for Simmentals against other Continental
breeds. It’s also possible to see how
breeding strategies lead to differing trends
in the genetic potential for each trait.
Fig 2: Age at first calving
Age at First Calving
Calving heifers at a younger age can make
great improvements to profitability by
reducing their rearing costs and increasing
the number of calves produced in a cow’s
lifetime. Starting earlier provides a cow with
more opportunities to produce a calf.
Simmental’s average genetic potential,
measured using EBVs, is favourable, in
this case more negative, compared to the
overall average of the Continental breed
group – see Fig 3. For animals born in 2021,
Simmentals on average have the genetic
potential to produce their first calf 10 days
earlier than the Continental average.
From the data Simmentals are performing
well for this trait, however the genetic trend
for the breed in the last 20 years, as per
Fig 2, should be noted. The change shown
is likely due to the link with carcase traits,
where strong selection for carcase traits
alone tends to have a negative impact on
fertility. This again highlights the importance
to Simmental breeders and commercial
producers of selecting bulls with good EBVs
for maternal, as well as carcase traits, when
breeding replacement heifers.
Figure 3: Productive lifespan
Productive Lifespan
This trait measures cow longevity whilst also
taking into account fertility. AHDB measures
the number of tagged calves an animal
produces in her lifetime, with a cap at 6.5
years or death, if sooner.
Simmentals have on average greater
potential to produce more calves in
their lifetime than the overall average for
Continentals. Fig 3. While the actual size of
this difference is quite small – around 0.06
calves for animals born in 2021, alongside
improvements in management, this greater
genetic potential could be enough to allow
an animal to produce an extra calf.
Figure 4: Calf survival
The genetic potential for this trait is
improving both in Simmentals and across
Continental breeds. The average Simmental
cow born in 2021 has the potential to
produce 0.11 more live calves than a
Simmental cow born in 2001 – almost twice
the current difference between Simmentals
and the average of all Continentals.
46 | www.britishsimmental.co.uk