Selective breeding can contribute to bovine tuberculosis control and eradication

Area of Science:

• Animal Genetics
• Veterinary Science
• Disease Control

Background:

• Bovine tuberculosis (bTB) remains a significant global threat to animal health and the economy.
• Intensified efforts are needed to achieve Officially Tuberculosis Free (OTF) status in affected regions.
• Genetic variation in host response to Mycobacterium bovis infection exists in cattle.

Purpose of the Study:

• To evaluate the potential of genetic selection as an additional tool for controlling and eradicating bovine tuberculosis.
• To explore the heritability of bTB resistance and its implications for selective breeding programs.
• To investigate the role of host infectivity in bTB transmission and its potential for genetic manipulation.

Main Methods:

• Review of existing literature on genetic variation, heritability estimates, and genomic studies related to bTB resistance.
• Analysis of simulation studies demonstrating the impact of genetic selection on disease dynamics.
• Consideration of genetic correlations between bTB resistance and other production traits.

Main Results:

• Heritability estimates for bTB resistance (0.06-0.18) suggest amenability to selective breeding.
• Genetic selection can be a constant, cumulative, and permanent control measure.
• No significant antagonistic genetic correlations were found between bTB resistance and productivity traits.
• Genomic research identified multiple markers and genes associated with bTB resistance, indicating a complex polygenic trait.
• Genetic variation in host infectivity also exists, suggesting dual-trait selection could accelerate eradication.

Conclusions:

• Selective breeding, targeting both host resistance and infectivity, is a viable complementary strategy for bTB control and eradication.
• Development of accurate genomic breeding values is crucial for effective selective breeding programs.
• Genetic improvement offers a permanent solution to reduce bTB incidence and severity.