Reply To: Mastitis In Sheep and Goats

  • theholisticgoat

    Organizer
    March 10, 2024 at 9:22 am

    Mastitis in dairy animals is a significant health issue that can impact milk production and quality. Understanding the heritability of mastitis is crucial for developing effective breeding strategies to enhance resistance to this disease.

    Key Insights from Research Papers

    • Heritability estimates for resistance to mastitis vary, with one study reporting a heritability of 0.27 ± 0.10, suggesting that genetic factors play a role in resistance to the disease1.
    • Low heritability estimates for clinical mastitis ranging between 2% and 4% were found in different dairy cattle breeds, indicating that while the trait is influenced by genetics, environmental factors also play a significant role2.
    • Genetic correlations between mastitis and other traits such as somatic cell score, longevity, and udder traits were found to be large, often exceeding 0.50, while the correlation with milk yield was moderate and unfavorable2.
    • Heritability for liabilities of clinical mastitis in Holstein dairy cows was estimated to be low, ranging from 0.06 to 0.09 across different lactations, with genetic correlations between disease liabilities being low or moderate3.
    • The impact of heifer mastitis on productivity does not appear to be significant when caused by coagulase-negative staphylococci, but the disease can have a long-term negative effect on udder health and milk production when major pathogens are involved4.

    Conclusion

    The heritability of mastitis in dairy animals is generally low, suggesting that while there is a genetic component to resistance, environmental and management factors are also important. Genetic correlations with other traits indicate that breeding for mastitis resistance could have implications for other important production traits. The variability in heritability and genetic correlations across studies highlights the complexity of the disease and the need for tailored breeding and management strategies to mitigate its impact.