Factors that influence the test day milk yield and composition

Area of Science:

• Animal Science
• Dairy Science
• Goat Production

Background:

• Accurate assessment of dairy goat performance requires understanding factors influencing milk yield and composition.
• Previous studies have identified various influences, but breed-specific and seasonal effects warrant further investigation.

Purpose of the Study:

• To investigate factors affecting test day milk yield (TDMY) and milk constituents (protein, fat, lactose, total dry extract) in Alpine and Saanen goats.
• To analyze the influence of season, age at kidding, kidding order, and genetic grouping on milk production traits.

Main Methods:

• Utilized 110,732 weekly milk production records and 19,271 monthly milk constituent records from 1997-2010.
• Applied data filtering criteria including kidding order, number of kids, milk control year, genetic grouping, and lactation duration.
• Considered goats aged >300 days at calving and <6 years at control.

Main Results:

• Milk production was higher during the dry season compared to the rainy season.
• Test day milk yield (TDMY) increased with goat age at kidding but decreased with higher kidding order.
• Genetic grouping did not consistently influence all traits across both breeds; influencing factors varied between Alpine and Saanen breeds.

Conclusions:

• Seasonal effects and age at kidding are significant drivers of milk production and composition in dairy goats.
• Breed-specific analysis of influencing factors is essential for developing effective herd management and evaluation models.
• Understanding these variables is critical for optimizing dairy goat breeding programs and improving overall farm productivity.