Page 53 - Hereford Magazine 2021

Photo: By Nicole Troost. Photo: By Maria Robbie – Otapawa Station.

4. MAINTENANCE cow should also be a consideration. Keeping an eye on the
In addition to getting pregnant, giving birth to a live calf, pedigree of the cow, and the bull she is being mated to, allows
weaning the calf, and getting back in calf, a maternal cow breeders to manage inbreeding in the herd at an acceptable
should perform all of these tasks without level. Similarly, breeders may be interested
consuming excessive amounts of feed. Given A maternal in the genetic condition status of the female
feed costs are among some of the most as this will allow them to avoid carrier to
expensive costs on a farm, the weight of a female in a carrier mating, although this becomes
mature cow will have a major influence on New Zealand less important when the bulls being used
net profitability. This is because, in general, Hereford herd in the herd have been tested free for the
lighter cows will tend to eat less, thus having should get in relevant genetic conditions. In the same
lower feed requirements and being less way, Hereford producers breeding for polled
expensive to maintain. Conversely, given calf, give birth animals may wish to know the horn/poll
live weight is the major determinant in the unassisted to a status of the females to avoid producing
value of cull cows, heavier cows may provide live calf, raise horned calves (unless using a homozygous
higher returns when selling cull cows. It is that calf to polled bull). This is less of a consideration
important to achieve an appropriate balance for those wishing to breed only horned
between feed requirements over the lifetime weaning, and calves – given horns are recessive, simply
of the cow and her value as a cull animal. then get back in select bulls and females with visible horns.
The mature cow weight EBV describes calf, all the while
the genetic differences between cows in live maintaining CONCLUSION
weight at five years of age, and is expressed A maternal female in a herd should get in
in kilograms. A higher, more positive herself. calf, give birth unassisted to a live calf, raise
mature cow weight EBV indicates an animal that calf to weaning, and then get back in calf,
that would produce progeny with a higher mature weight all the while maintaining herself without needing to consume
than an animal with a lower mature cow weight EBV. While it excessive amounts of feed.
is important for Hereford breeders to optimise the balance Breedplan produces a number of EBVs that are important
between feed requirement and cull value, in general the ideal when considering a maternal female; namely days to calving,
maternal female should have a low to moderate mature cow scrotal size, gestation length, calving ease direct, calving
weight EBV, as this will reduce her feed requirements over ease daughters, birth weight, milk, and mature cow weight.
her lifetime. Ideally, a maternal female will have shorter days to calving
and gestation length EBVs than average (more negative
5. OTHER TRAITS EBVs are more desirable), while having larger scrotal size,
In addition to the Breedplan traits discussed above, it is calving ease direct and calving ease daughters EBVs (more
important to remember there are other important traits for positive EBVs are more desirable). She should also have a
a good maternal cow in the herd. She must still have good moderate birth weight (lower or moderate EBVs are more
structural soundness; after all, she spends much of her life desirable), and a moderate mature cow weight (lower or
moving around the paddock feeding, and needs good foot moderate EBVs are more desirable). The optimal milk EBV
and leg structure to allow her to move about with ease. A cow will depend on the environment, where Hereford breeders
with good structural soundness may last longer in the herd, in good country may prefer more positive milk EBVs, while
potentially improving her longevity. In a similar manner, a Hereford breeders on more marginal country may prefer
maternal cow should be in good general health. more moderate milk EBVs.
While not strictly related to her maternal ability, the horn/
poll status, genetic condition status, and pedigree of the

Year 2021 HEREFORD MAGAZINE 51