Interactions between milk production, heat stress, and ferti

Does level of milk production

affect cow's tolerance to heat stress?

Field fertility

Interactions between milk production, heat stress & fertility

Core body temperature cows in Brazil, US, and Middle East

Brazil

USA

Physiology

www.scholar.google.com

Rationale

Cows with greater milk production:

- Have greater dry matter intakes

- Have higher metabolism rates

- Lactating cows > body temp than dry

- Greater milk production > body temp

ref: West et al. 2003, Liang et al. 2013

Previous research findings

HO

JE

Local farms:

field fertility & milk prod

UCCE/NOAA:

milk production/core body temp

Materials and methods

Recorded core body temperature every 10 min

Results

Conclusions & comments

> Milk production = > core body temperatures

> Milk cows under heat stress for longer periods

Need to cool cows to match their production level...

Alex Souza, DVM PhD

Dairy consultant

ahsouza76@gmail.com