Guzerat indicine cattle and A2 milk production

Area of Science:

• Animal Genetics
• Dairy Science
• Food Science

Background:

• Cow milk's A1 beta-casein is linked to digestive discomfort in some individuals.
• A2 milk, produced by cows with the A2A2 genotype, offers an alternative by lacking A1 beta-casein.

Purpose of the Study:

• To determine beta-casein gene allele and genotype frequencies in Guzerat cattle.
• To assess the potential for A2 milk production and selection within this breed.

Main Methods:

• Genotyping of 283 Guzerat cows across 10 herds.
• Analysis of beta-casein gene variants.

Main Results:

• The A2A2 genotype frequency was 0.80, and the A2 allele frequency was 0.90.
• Guzerat cattle exhibit a high prevalence of the A2A2 genotype, favorable for A2 milk production.
• Marker-assisted selection can efficiently increase A2A2 genotype frequency without reducing genetic diversity.

Conclusions:

• Guzerat cattle possess significant potential for A2 milk production.
• The breed's genetic makeup supports the feasibility of selecting for A2 milk production.
• Targeted selection strategies can enhance A2A2 genotype frequency in Guzerat cattle populations.