Key Strategies for Breeding Climate-Resilient Livestock

As climate variability and extreme weather events increasingly impact agriculture, breeding climate-resilient livestock is a crucial adaptation strategy. This article outlines the key approaches and considerations in breeding livestock that can thrive despite changing environmental conditions.

Defining Resilience Traits

Resilience in livestock refers to the ability of animals to maintain productivity despite environmental stressors. However, the specific traits that define resilience can vary:

• Dairy goats in Atlantic climates: Resilience is the stability of milk production under fluctuating weather conditions .
• Dairy sheep in Mediterranean climates: Resilience refers to their ability to improve performance under heat stress .
• More generally, resilience is viewed as the ability of animals to continue producing in line with their genetic potential, despite variations in weather .

Breeding Program Strategies

To integrate climate resilience into breeding programs, several strategies have been recommended:

1. Selection Indices: Resilience traits should be included in selection indices, typically contributing 10-20% of the total selection weight for dairy goats and sheep . This ensures that resilience is prioritized without overshadowing other important traits such as milk yield, growth, or fertility.
2. Balancing Traits: A successful breeding program needs to balance resilience traits with other key functional and production traits . Selecting for only resilience could compromise gains in production traits if not managed properly.
3. Genomic Data: Genomic data can identify specific resilience-related genes, which can be targeted in breeding efforts . This involves using DNA markers that are associated with traits like heat tolerance or drought resilience.
4. Crossbreeding: Introducing genetics from heat-tolerant breeds through crossbreeding is another method to improve resilience, especially in regions where climate extremes are frequent .
5. Breed for Specific Adaptations: In some cases, breeding programs should focus on specific adaptations, such as selecting for heat or drought tolerance . For instance, indigenous breeds are often more resilient to local climate conditions than imported breeds.

Measuring Resilience

Accurately measuring resilience is essential for breeding:

• Production Stability: One approach to measuring resilience is assessing the stability of production in varying climatic conditions. This helps identify animals that continue to perform well even when faced with challenges like heat waves or feed shortages .
• Performance Variability: Metrics can be developed to describe how an animal’s performance fluctuates with changes in feed availability or climate . This variability is crucial for identifying the most resilient animals.
• Genetic Parameters: Estimating heritability and genetic correlations for resilience traits enables breeders to understand how these traits are passed on and interact with other traits .

Complementary Strategies

Breeding for climate resilience should be combined with other adaptive measures:

1. Feeding Strategies: Diverse forages and climate-resilient feed additives can be used alongside resilient breeding to maintain nutrition under variable conditions .
2. Management Practices: Implementing management practices such as providing shade, using cooling systems, or bathing animals in hot climates can reduce heat stress and complement breeding efforts .
3. Species Replacement: In regions facing extreme climate challenges, switching to more heat-tolerant species such as goats or camels may be a more effective long-term solution than breeding within existing species .

Considerations for Resilience Breeding

There are important trade-offs and considerations in breeding for climate resilience:

• Antagonistic Relationships: Often, there are antagonistic relationships between resilience traits and production traits. For instance, selecting for heat tolerance might lead to reduced milk production .
• Production Gains: Breeding for resilience might slow down progress in production traits if not optimized correctly . The challenge is to maintain a balance where productivity is not sacrificed for the sake of resilience.
• Tailored Strategies: Different climates and production systems may require specific definitions of resilience and tailored breeding strategies . What works in a hot, arid climate may not be effective in a humid, tropical environment.

Conclusion

As climate variability increases, livestock producers need to incorporate resilience into their breeding programs. This can be achieved through a combination of selecting for specific resilience traits, using genomic data, crossbreeding, and complementing breeding with improved management and feeding strategies. By taking a holistic approach that balances production and resilience, livestock producers can ensure their animals remain productive under changing environmental conditions.