- Special Sections - Public Notices January is an extremely
important “checkpoint” in spring heifer-development programs.
The key to proper heifer development lies in understanding the
factors that influence conception in yearling heifers. One key
factor regulating heifer fertility is age at puberty. Most
producers do not consider age at puberty of their heifers to be
a major problem, yet few know how many heifers are actually
cyclic at the beginning of the breeding season. A Nebraska study
demonstrated that the proportion of heifers that were pubertal
on the first day of the breeding season varied greatly over five
consecutive years in a single herd. The percentage of heifers
that were pubertal on the first day of the breeding season
ranged from only 21 percent to as high as 64 percent over the
five-year period. For maximum fertility and reproductive
performance, heifers must have had at least one estrus before
the beginning of the breeding season. Our goal, then, is to
incorporate reproductive-management te