Heifer Pregnancy

From BIF Guidelines Wiki

Pregnancy diagnosis for first-calf heifers should be done within 60 to 65 days after the end of the breeding season. This allows for pregnant and open heifers to be identified, where selection can be focused on pregnant heifers. A heifer exposure inventory is necessary to ensure efficient use of pregnancy diagnosis data on heifers.

Contemporary Group Information

1. Yearling Weight Contemporary Group Criteria

2. Heifer Pregnancy Management Code

3. Breeding Season Start and End Dates

4. Exposure

5. Breeding Pasture and/or Sire Effect

Genetic Evaluation

Heifer pregnancy EPD estimates differences among individuals in the proportion of their daughters that will successfully conceive to calve at two years of age. Computation of this EPD requires exposure data and pregnancy diagnosis results. Heifer pregnancy EPD is expressed as the probability of successful conception and predicts differences among individuals (typically sires) in the ability of their daughters to conceive and calve at two years of age.

Usage

Heifer pregnancy is an economically relevant trait because it will directly impact replacement heifers retained. The number of breeds generating heifer pregnancy EPD has increased, therefore it is likely an across-breed heifer pregnancy EPD may be available. For increased reproductive efficiency in heifers, recommendations for exposing heifers should be followed. Structural characteristics and parental performance history should outweigh visual characteristics assumed related to reproductive performance [1] . Scrotal circumference of yearling bulls can be used an indicator of their daughters' expected heifer pregnancy.

References

  1. Sprott, L.R. and T.R. Troxel. 2012. Management of replacement heifers for a high reproductive and calving rate. Texas AgriLife Extension B-1213. [1]