Selection for bull fertility: a review

Area of Science:

• Animal Science
• Reproductive Biology
• Genetics

Background:

• Cattle fertility is vital for production economics, with female fertility extensively studied and improved.
• Bull fertility, critical for offspring production, has been largely overlooked despite its economic importance.
• Improving bull fertility offers potential for increased conception rates and enhanced economically relevant production traits.

Purpose of the Study:

• To review current measurements of beef bull fertility.
• To discuss future genetic evaluation strategies for beef bull fertility.
• To explore potential genetic improvement strategies for bull fertility.

Main Methods:

• Literature review of published studies on bull fertility traits.
• Analysis of genetic correlations between bull fertility and other production traits.
• Discussion of current and future genetic evaluation tools for bull fertility.

Main Results:

• Bull fertility traits are genetically correlated with average daily gain, heifer pregnancy, and calving interval.
• Bull fertility traits exhibit low to moderate heritability, suggesting potential for genetic improvement through selection.
• Correlations between specific bull fertility parameters (e.g., sperm concentration, motility) vary across studies.

Conclusions:

• Enhancing bull fertility is essential for optimizing cattle production efficiency.
• Integrating bull fertility traits into selection indices can provide advanced tools for producers.
• Further research into genetic evaluation and improvement strategies for bull fertility is warranted.