“Sheep are most comfortable at 45-70 degrees F. When humidity sets in or temps go above 75 degrees F, sheep begin to feel the negative effects of the heat.”
Animal factors
Lambs are very susceptible to heat stress because of their high metabolic heat production, higher normal respiration rate, large surface area relative to their mass and limited fleece length. The increase in metabolic heat production during late gestation can predispose ewes to increased heat stress.
Shorn sheep kept in yards or paddocks without shade have no protection from the sun and may become sunburnt and heat stressed. Panting is the main way sheep deal with heat stress but this also has little cooling effect at ongoing high temperatures. Cattle lose their body heat by evaporation of sweat and by panting.
Sheep will drink a lot of water during hot weather to help cool themselves down. If you're lucky enough to have an automatic water trough, the daily checks to ensure it's working properly and is clear of algae and other debris is important.
Some livestock tolerate heat better than others. Sheep and goats tend to be less susceptible to heat stress than swine, cattle, llamas and alpacas. However, goats tend to tolerate heat better than sheep. Goats with loose skin and floppy ears may be more heat tolerant than other goats.
Providing shade or shelter for livestock helps them to deal better with the heat and can reduce production losses that may result from heat stress. Heat stress can have a significant effect on production and reproduction so it is important that shelter and a plentiful supply of cool water are available.
While heat stress (exhaustion or stroke) is not very common in sheep and goats in temperate climates, it may occur, especially if stock are handled during the hottest part of the day.
Heat stressed sheep tend to have a reduced appetite meaning weight loss and decreased feed efficiency. There are also changes to behaviour such as seeking out shade and increasing water, which you can learn about here.
Bedding is mainly used from fall through spring when sheep and goats are housed inside to get out of the cold, wet weather. It is also important to provide bedding during the summer months for livestock during lambing or kidding and in cases of confinement.
Light-colored animals, newly shorn sheep and other animals that are clipped can suffer from sunburn and the parts of animals that normally lack hair cover can be sunburned.
High rainfall and high winds combined with temperatures below normal will cause mortalities in young animals, especially newly shorn sheep without shelter. The impact of the cold weather will depend on its duration, rainfall, wind speed and temperature—the 'wind chill' factor can double heat loss.
“Despite the lamb's built-in wool blanket, winter can be stressful for young sheep,” says Julian (Skip) Olson, DVM, technical services manager for Milk Products. “Sheep are most comfortable at 45-70 degrees Fahrenheit.
Over time, unshorn wool could eventually impede movement.” Sheep can overheat and die in the summer months if not shorn, and become the target for parasitic species such as ticks, lice, mites, and the maggots that cause fly strike, a gruesome and even deadly condition.
Shearing for wool is done in early summer. This enables sheep to survive without protective coat of hair in hot weather. Also The fur of the sheep traps air and acts as an insulator so the heat generated does not flow out and keeps the animal warm in winter.
There are several visible signs associated with heat stress in animals, including: • increased effort breathing or difficulty breathing; • excessive panting; • drooling; • bright red gums; • anxious behaviour, which includes agitation and excess barking; • excessive water consumption; • vomiting or diarrhea; • weakness ...
Professor John Webster of the University of Bristol found that, like humans, sheep visibly express emotions. When they experience stress or isolation, they show signs of depression similar to those that humans show by hanging their heads and avoiding positive actions.
After the introduction of the rams, ovulation will occur at 3–4 days but will be an undetectable 'silent heat'. A silent heat is characteristic of the first ovulation: of the breeding season, usually March to the end of May. induced by the ram effect. of puberty.
The sheep many times will start slinging their heads and jumping in the air because they are literally choking. Sometimes they simply back up from the trough and act like they don't like the feed and some will attempt to eat but retreat from the trough each time they try to get a bite.
Signs of Heat Stress
Other signs to look for are lack of overall energy, increased panting, drooling and increased respiratory rate. It is common for sheep and goats to shade up, especially if their water source is near the shade provided to them.
Sheep are produced in a wide range of climates—from the arid and semi-arid parts of the inland region, to the medium to high rainfall areas of New South Wales, Victoria, South Australia, Tasmania, Queensland and southern Western Australia.
They shun forests, live in the open, and feed upon the moun- tain grasses. The climatic conditions in such regions as the higher parts of Sardinia and Sicily are probably most suitable for sheep. The days are hot, the nights cool, the winters mild, with more or less rainfall; and the summers are dry (2).
To help the sheep calm down, leave them in the yards for about 30 minutes before working with them, if possible. Calm sheep are more likely to move smoothly through the yard and less likely to move abruptly or charge gates, fences or people.
Sheep have survived long, cold winters outside for thousands of years, thanks to their fluffy warm fleeces. No matter how harsh the environment, the wool on their backs keeps them warm and dry. Due to its crimped nature, wool fibres form millions of tiny air pockets that trap the air and slow the transfer of heat.
A lamb shaking but not cold could be a lamb fever and caused by any of a variety of infections that are common in lambs. The normal temperature range for a lamb is 38.5 – 39.5 degrees Celcius. A higher than normal temperature is a good indication of an infection.