Genetic variability of milk fatty acids

Area of Science:

• Animal Science
• Nutritional Science
• Genetics

Background:

• Milk fatty acid (FA) profiles often deviate from optimal human health standards.
• While feeding impacts milk FA, genetic influences are increasingly recognized as crucial for variation.
• Understanding genetic variability is key to improving milk fat nutritional quality.

Purpose of the Study:

• To summarize current knowledge on genetic variability in milk FA composition.
• To explore breed-specific differences and heritability of milk FAs.
• To identify genetic markers influencing milk FA profiles.

Main Methods:

• Comparative analysis of FA profiles across different cattle breeds (e.g., Holstein vs. Jersey).
• Estimation of delta-9 desaturase activity using specific FA ratios.
• Identification and analysis of single nucleotide polymorphisms (SNPs) in genes like SCD1 and DGAT1.

Main Results:

• Significant breed differences exist, with Jersey milk having higher saturated FAs than Holstein.
• Heritability estimates for milk FA proportions range from 0.00 to 0.54.
• Specific polymorphisms in SCD1 (V allele) and DGAT1 (A allele) are linked to increased FA unsaturation.

Conclusions:

• Breed selection is a viable strategy to enhance milk fat's nutritional value.
• Genetic approaches, combining molecular and quantitative methods, are essential for improving milk FA quality.
• Targeted animal selection based on identified genetic markers can optimize milk fat composition for health benefits.