Variation in immunoglobulin transfer from ewes to lambs

Area of Science:

• Animal Science
• Immunology
• Genetics

Background:

• Immunoglobulin G1 (IgG1) is crucial for passive immunity transfer in newborn lambs.
• Factors influencing IgG1 concentrations in lambs are complex and may involve maternal and genetic components.
• Understanding these factors is vital for optimizing lamb health and survival.

Purpose of the Study:

• To investigate the correlations between lamb serum IgG1 concentrations and various maternal and environmental factors.
• To identify significant breed differences in lamb serum IgG1 levels.
• To examine the relationship between ewe colostrum/IgG1 yield and milk production.

Main Methods:

• Statistical analysis of IgG1 concentrations in two-day-old lambs.
• Inclusion of factors such as litter size, lambing date, gestation length, and dam age.
• Comparison of IgG1 levels across different lamb breeds and crossbreds.

Main Results:

• Significant correlations found between lamb IgG1 levels and litter size, lambing date, gestation length, and dam age.
• Distinct breed differences observed: Finnish Landrace, Welsh Mountain, and Soay lambs had higher IgG1, while Border Leicester, Oxford Down, and Southdown had lower levels.
• Crossbred lamb IgG1 concentrations were predictable based on parent breeds; ewe colostrum yield and IgG1 production were linked to milk production.

Conclusions:

• Maternal factors and breed genetics significantly influence passive immunity transfer via IgG1 in lambs.
• Breed selection and management practices can impact lamb serum IgG1 levels.
• Heritability estimates for lamb IgG1 concentration (0.10) and ewe IgG1 production (0.45) suggest a moderate genetic component for maternal contribution.