Effects of environmental management on seasonal decrease in milk production in dairy cattle

Area of Science:

• Dairy Science
• Animal Husbandry
• Environmental Physiology

Background:

• Seasonal variations significantly impact dairy cow productivity.
• Heat stress negatively affects milk yield and cow well-being.
• Effective management strategies are crucial for mitigating seasonal production losses.

Purpose of the Study:

• To evaluate the impact of season on milk production in Holstein dairy cows.
• To assess the efficacy of fans and sprinklers in managing seasonal heat stress.
• To identify optimal management practices for maintaining milk production throughout the year.

Main Methods:

• A longitudinal observational study involving 141 dairy herds.
• Data collection included production and reproduction records from the Dairy Herd Improvement Association database.
• Interviews with owners identified the placement of fans and sprinklers; mixed model ANOVA analyzed the data.

Main Results:

• Summer heat decreased daily peak milk production across all parity groups, with diminishing effects later in lactation.
• Sprinkler use enhanced peak milk production in parity-1 and parity-3+ cows.
• Fans did not significantly alter seasonal effects on milk production; 305-day milk production decreased for parity-2 and -3 cows calving in summer.

Conclusions:

• Sprinklers show potential for increasing peak milk production and reducing heat stress in high-producing cows.
• Veterinarians should exercise caution when recommending fans and sprinklers due to wide confidence intervals for effectiveness.
• Optimizing calving periods for parity-2 and higher cows (October to June) can enhance 305-day milk production.