Climatological and genetic effects on milk composition and yield

Area of Science:

• Dairy Science
• Animal Husbandry
• Climate Impact Studies

Background:

• Milk composition and yield are influenced by various factors, including genetics and environment.
• Climate change presents growing challenges to livestock production systems worldwide.
• Understanding breed-specific climate sensitivities is vital for sustainable dairy farming.

Purpose of the Study:

• To investigate the impact of climate on milk yield, composition, and udder health in dairy cows.
• To compare the climate sensitivity of Jersey and Holstein breeds regarding milk production and quality.
• To identify key variables affected by climate and explore potential mitigation strategies.

Main Methods:

• Analysis of milk yield, somatic cell count (SCC), and milk composition data in relation to climatic variables.
• Statistical modeling to determine the percentage of error variance attributable to climate for different traits.
• Calculation of genetic and phenotypic correlations between milk yield, SCC, and milk components.

Main Results:

• Climate significantly affected all measured dairy cow responses, with varying degrees of impact.
• Jersey milk yields were less sensitive to climate than Holstein, but Jersey milk composition was more sensitive.
• Somatic cell count (SCC) was climate-affected, though less so than other variables, with genetic correlations suggesting potential mastitis increase with high milk yield selection.

Conclusions:

• Environmental modification strategies, informed by response surface models and climate interaction estimates, are needed to improve dairy cow performance.
• Breed-specific responses to climate necessitate tailored management approaches.
• Balancing milk yield selection with udder health considerations is essential for sustainable dairy production.