Sheep Summer Welfare: Heat, Fly Strike, and Pasture Management

Summer presents specific welfare challenges for sheep including thermal stress, blowfly strike risk, and internal parasite burden. Proactive summer management is essential.

Key Facts

Sheep have a thermoneutral zone of 5-25 degrees Celsius; temperatures above 30 degrees cause heat stress
Wool acts as insulation in both directions — unshorn sheep in hot weather suffer more than shorn sheep
Internal parasites including Haemonchus contortus multiply rapidly in warm, wet summer conditions
FAMACHA scoring (anaemia assessment) helps target anthelmintic treatment to the most affected animals

Welfare Considerations

Summer welfare requires attention to multiple simultaneous threats. Heat stress causes reduced feed intake, increased water consumption, and respiratory distress — shearing before hot weather significantly reduces thermal stress. Flystrike risk peaks in July-August requiring preventative treatment and daily inspection. Targeted anthelmintic treatment based on FAMACHA scoring reduces selection pressure for drug resistance while protecting welfare. Pasture rotation breaks parasite life cycles and reduces burden.

What You Can Do

Shear sheep before hot weather to reduce thermal stress risk during summer months
Implement preventative blowfly treatment from May and conduct daily inspections throughout summer
Adopt FAMACHA scoring for targeted anthelmintic treatment rather than blanket dosing
Ensure continuous access to fresh water — sheep require 2-4 litres daily in summer, more in hot conditions