Activity and milk compositional changes following experimentally induced Streptococcus uberis bovine mastitis

Area of Science:

• Veterinary Medicine
• Animal Science
• Dairy Production

Background:

• Bovine mastitis is a significant economic challenge in the dairy industry.
• Streptococcus uberis is a common causative agent of intramammary infections.
• Monitoring milk constituents and animal behavior can aid in early disease detection.

Purpose of the Study:

• To investigate the effects of experimental Streptococcus uberis mastitis on milk composition and cow physical activity.
• To evaluate the utility of automated milk analysis and pedometers for detecting mastitis-induced changes.

Main Methods:

• Twelve Holstein cows were experimentally infected with Streptococcus uberis.
• Milk fat, protein, and lactose percentages were analyzed in real-time.
• Cow activity was monitored using pedometers, measuring steps and resting time.

Main Results:

• Infected cows experienced a reduction in milk yield (approx. 1.6 kg/d) and lactose percentage.
• No significant differences in milk fat or protein percentages were observed between infected and control cows.
• Physical activity decreased, with fewer steps per day and more resting minutes in infected cows.

Conclusions:

• Experimental Streptococcus uberis mastitis impacts milk yield and lactose levels.
• Changes in cow activity patterns, including reduced locomotion and increased rest, are associated with mastitis.
• Automated milk analyzers and pedometers can effectively detect subclinical changes caused by mastitis.