Efficiency of selection strategies for halothane-negative gene.

Area of Science:

• Animal Genetics
• Quantitative Genetics
• Swine Breeding

Background:

• Halothane sensitivity in pigs is a significant concern in breeding programs.
• Accurate estimation of the halothane-negative allele frequency is crucial for effective selection.
• Current methods may not fully leverage available pedigree information.

Purpose of the Study:

• To illustrate a method for estimating halothane-negative allele frequency in boars.
• To evaluate the accuracy of this estimation method under various sampling schemes.
• To assess the impact of this method on selection programs for reducing halothane sensitivity.

Main Methods:

• Utilized a method incorporating individual, mate, and relative (parents, siblings, offspring) data.
• Employed Monte Carlo simulation to measure the accuracy of allelic frequency estimates.
• Calculated selection differentials based on estimated allelic frequency for accuracy assessment.

Main Results:

• The method's accuracy was validated through simulations.
• Progeny testing showed selection differentials of .017-.044 (base boars) and .013-.025 (offspring) with 90% selection.
• Closed herd situations with two generations of data yielded higher selection differentials, increasing with more intense selection (e.g., .046 to .066).

Conclusions:

• Intense selection for reduced halothane sensitivity is most effective with large litter numbers and multi-generational data.
• The developed estimation procedure can enhance current boar screening and selection programs.
• Improved allelic frequency estimation will aid in reducing halothane sensitivity in swine populations.