New ideas in heifer selection and breeding for suckler herds
Target management strategies and goal setting should be used to ensure money invested in genetics is being put to good use.
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.
Farmers who subscribe to this method are advised to grow heifers to 65-70% of their estimated mature weight before breeding.
Interestingly, some research from the US recently has suggested that it is both biologically and economically feasible to breed heifers at significantly younger ages and at lighter weights. It has been shown that breeding heifers at 53% of estimated mature body weight did not adversely affect reproduction or calf production traits and, furthermore, reduced the feed costs associated with heifer development (compared to heifers fed to reach a pre-breeding target of 60% of predicted mature weight).
Breeding heifers at a younger age and at lighter weights yields a calf and a return on investment earlier than waiting to breed until the heifer is heavier and older, but may require careful management at calving.
Selecting 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, farmers 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.
nPhenotype: The most obvious factor that should be considered when selecting replacements is phenotype. Though physical needs may vary slightly between herds, most farmers 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.
n 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 play a major role in heifer fertility, and it is possible to select for early maturing females. British breeds such as Angus and Hereford generally reach puberty earlier than Continental breeds such as Charolais or Limousin.
Heifers from dairy herds
Many suckler herds try to source replacement heifers from dairy herds, in order to improve milk volumes. This can be an excellent strategy, and will deliver good maternal traits. Limousin, Simmental and Angus heifers from dairy herds tend to make good suckler cows. Take care that the dams are not extreme types, because this will have an adverse effect on the carcass confirmation of stock.
