Abstract
Clinical bottom line
 Heat stress appears to generally suppress innate immune function in both dry and lactating dairy cows. Immune effects that are decreased include cytokine production, proliferation of immune cells, migration of lymphocytes to the udder and cell viability. This may lead to an increase in the risk of clinical diseases such as mastitis and metritis. 
Highlights
Summary of the evidenceSample size: 15 cooled dry cows and 15 heat stressed cows. 5 from each group were induced Streptococcus uberis IMI at 5DIM
Very low cow numbers Measured over 0-36 hours post IMI for cytokines and to 40 weeks into lactation for physiology All cows were cooled after calving Insufficient power to conclude an effect on milk yield, any numerical effects seen are valid as the primiparous group were not included
Gene expression changes to heat above 35 C include:
Summary
Sample size: 15 cooled dry cows and 15 heat stressed cows. 5 from each group were induced Streptococcus uberis IMI at 5DIM. Sample size: 15 cooled dry cows and 15 heat stressed cows. 5 from each group were induced Streptococcus uberis IMI at 5DIM. Intervention details: THI in non-cooled conditions was 77.9-78.3. Water sprinklers and shade in this group. Outcome studied: Rectal temperature, respiratory rate, milk yield and composition, blood parameters: Immune response genes (TLR2, IL1-β, IL6, IL8, IL10, and TNFα)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
