Ewes on heat seek out rams and stay close to them, repeatedly rubbing their necks or bodies against the rams. The effects of heat stress on physiological traits in sheep 27 Maced. Australia to the Middle East is one of the world’s longest sea transport routes of live sheep for slaughter, usually taking about 20 days. Observation of heat One of the best indicators of ruttishness is the presence of rams among ewes. Teasers, or rams with aprons, which prevent penetration, can be used to identify ewes on heat. Some livestock tolerate heat better than others. The panel has recommended that the heat stress risk assessment (HSRA) framework focus on animal welfare, rather than mortality risk, using a wet bulb temperature welfare limit for exported sheep based on weight, breed, condition score, acclimatisation, fibre length and where they are sourced from. J. Anim. Sci., 3 (1) 25–29 (2013) maintenance feed level. However, goats tend to tolerate heat better than sheep. We found sheep experienced heat stress on more than half of voyages to the hottest port in the Middle East, Doha, over three summers from 2016 to 2018.. The present study was conducted to examine the physiological response and HSP70 secretion in four extensively managed indigenous sheep breeds with little access to shade. The federal government recently banned sheep exports to the Middle East between June 1 and September 14 this year, due to heat stress risks. READ A model sheep enterprise on a modest farm The welfare risk to sheep from heat stress is highest on voyages departing Australia in our winter, and arriving in the Persian Gulf in the Northern Hemisphere summer. Sheep and goats tend to be less susceptible to heat stress than swine, cattle, llamas, and alpacas. Severe heat stress exposed. The heat index (temperature plus humidity) is a more accurate measure of heat stress than temperature alone. Heat stress is one of the most challenging environmental conditions affecting livestock production especially in the tropical regions of the world. The provision of shade shelter is suggested as a practical measure applica-