Interactions of climatic factors affecting milk yield and composition

Area of Science:

• Animal Science
• Agricultural Meteorology
• Dairy Science

Background:

• Dairy production is influenced by environmental factors.
• Understanding climate impacts on milk yield and composition is crucial for optimizing dairy farm management.

Purpose of the Study:

• To evaluate the interactive effects of maximum temperature, minimum relative humidity, and solar radiation on milk yield and constituent traits in Holstein and Jersey cows.
• To develop regression models for predicting optimal climatic conditions for milk production.

Main Methods:

• Utilized second-order regression models to analyze climate variable interactions.
• Examined six key variables: Holstein and Jersey milk yields, Holstein fat and Feulgen-DNA reflectance, and Jersey protein percent and yield.
• Applied response surface methodology to determine optimal climatic conditions.

Main Results:

• Maximum temperature exerted the most significant influence on milk yield and constituent traits.
• Optimal milk production conditions were identified as maximum temperatures below 19.4°C, increasing solar radiation, and moderate humidity (33.4–78.2%).
• Specific optimal conditions were predicted for Holstein fat and Jersey protein percentages, highlighting the role of temperature, humidity, and solar radiation.

Conclusions:

• Climate variables, particularly maximum temperature, significantly interact to affect dairy cow performance.
• Response surface methodology is effective for identifying optimal climatic conditions for milk production and quality.
• Management strategies should consider specific climatic thresholds to enhance dairy productivity.