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Genetic effects on beef heifer puberty and subsequent reproduction
L C Martin1, J S Brinks, R M Bourdon
1Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
Journal of Animal Science
|December 1, 1992
Summary
Beef cattle breeders can improve fertility by selecting for age at puberty (AP). Traits like scrotal circumference (SC) in males and crossbreeding influence AP, aiding genetic selection for reproductive efficiency.
Area of Science:
- Animal Genetics
- Reproductive Biology
- Beef Cattle Production
Background:
- Significant genetic variation exists for age at puberty (AP) in beef cattle.
- Breed characteristics like mature size and milk production influence AP.
- Heterosis impacts puberty measures and scrotal circumference (SC).
Purpose of the Study:
- To explore genetic variation in beef cattle for age at puberty (AP).
- To evaluate the influence of heterosis and specific traits on puberty and fertility.
- To provide insights for breeding strategies to enhance reproductive efficiency.
Main Methods:
- Analysis of genetic variation within and between beef cattle breeds.
- Assessment of heterosis effects on puberty and scrotal circumference.
- Evaluation of genetic relationships between male fertility indicators and female AP.
Main Results:
- Crossbred heifers reach puberty earlier and at heavier weights than straightbreds.
- Scrotal circumference (SC) in yearling bulls is a strong indicator of AP.
- A positive genetic correlation exists between bull SC and female offspring AP.
Conclusions:
- Selecting for traits like SC can directly improve AP and fertility in beef cattle.
- Indirect selection for size, milk, and calving ease can create a favorable genetic environment for fertility.
- Both within- and between-breed selection, including crossbreeding, are effective strategies for commercial producers to enhance AP.
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