The fetus grows tremendously in the last trimester of pregnancy and requires substantial nutritional resources. The fetus is given priority over other body functions in the growing heifer, so adequate nutrition is essential. Care should be taken, however, to avoid overfeeding as fat heifers experience many problems in first lactation. Adequate exercise and proper conditioning are important in preparing heifers for their first calving. The heifer needs to be in shape for the task.
Recommendations Use only bulls with dystocia proofs when breeding heifers.
This recommendation eliminates the use of beef or unproven dairy bulls in natural service for heifers, which is also good advice for genetic reasons. It also restricts use of AI sample sires to the cow herd, though breeding 3 or 4 heifers to each young sire can spread the risk. This recommendation must not be extended to include selection for the easiest calving sires for heifers. Such a process is too restrictive to allow selection on other economically important traits. Do not use dystocia proofs in making selection decisions for second or later lactation cows.