Brian Reidy: Selecting replacement heifers for the suckler herd

Breeding heifers at a younger age and at lighter weights yields a calf and return on investment earlier than waiting to breed until the heifer is heavier and older, but may require more careful management at calving, writes ruminant nutritionist Brian Reidy

Breeding heifers at a younger age and at lighter weights yields a calf and return on investment earlier than waiting to breed until the heifer is heavier and older, but may require more careful management at calving, writes ruminant nutritionist Brian Reidy.

Breeding replacement heifers is a very important part of any suckler herd.

Up until recently, breeding heifers before two years of age was almost unheard of, but now it is common practice to breed heifers at 15 months old or even younger. 

The current approach to heifer development is based around the concept of “target weights,” in which heifers are fed to a target percentage of their mature body weight before breeding. 

Producers who subscribe to this method are advised to grow heifers to 65-70 per cent of their estimated mature weight before breeding.

Breeding heifers at a younger age and at lighter weights yields a calf and return on investment earlier than waiting to breed until the heifer is heavier and older but may require more careful management at calving. Bull selection is also critical when calving early.

With a strong beef trade at present, the value of in calf cows and heifers has also increased significantly and many herds are considering the option of putting extra females in calf for sale over the next year.

Selecting replacement heifers

Many factors influence fertility and age of puberty in beef females, including genetics, nutritional status, and body weight. Certain management practices can reduce the average age of puberty in replacement heifers. Heifer selection using genetic evaluation is also an important aspect in improving herd fertility.

By selecting for certain physical, performance, and genetic traits, producers can select the replacement heifers that are most likely to be productive and reproductively efficient. The combination of good management decisions and measured female selection can significantly improve the overall profitability of the suckler herd.

Functionality

The most obvious factor that should be considered when selecting replacements is functionality. 

Though physical needs may vary slightly between herds, most producers should look for structurally sound females that have an adequate degree of muscling, as well as sufficient volume and depth of body. Heifers with a poor frame, insufficient muscling, and a lack of depth and body are more likely to have decreased productivity and longevity.

Performance

As most suckler producers sell calves shortly after weaning, calf growth rate and weaning weights are of significant economic importance. Faster-growing heifers should ultimately produce calves that are heavier at weaning than calves whose dams were slow-growing.

Temperament

Temperament is often overlooked when selecting breeding stock. Calmer animals are obviously much easier to handle, and less excitable animals have been shown to have increased average daily gains when compared to more easily agitated cattle.

Age at puberty

Genetics do play a major role in heifer fertility, and it is possible to select for early maturing females. Traditional breeds such as Angus and Hereford generally reach puberty earlier than females of Continental breeds such as Charolais or Limousin.

Stars

A system not fit for purpose, but for anyone in the SCEP scheme, stars have to be looked at to some degree.

Some suckler herds source replacement heifers from dairy herds to improve milk volumes. This has become common as producers chase stars. This approach may deliver maternal traits, but take care that you don’t end up with narrow, low-weight progeny and disappointing future sale days.

• Brian Reidy is an independent ruminant nutritionist at Premier Farm Nutrition.