Sheep 10 facts
1. a sheep was one of the first ever successful blood donors
In 1667, Frenchman Jean-Baptiste Denis performed the first-ever transfusion of blood from an animal to a human, transferring blood from a sheep to a 15-year old boy and a labourer, both of whom survived the process. British physician Richard Lower performed the first-ever successful animal blood transfusion in 1665 on a dog.
3. Sheep are particularly used as models for endocrinology, reproduction and pregnancy and foetal development
Sheep are large mammals that have many similarities to humans in terms of physiology. They are easy to handle and suffer from many diseases which affect humans. They also have short gestation periods yet give birth to young of a similar weight to human babies, making them excellent for studying development and genetics. They are also used extensively in veterinary research, studies of digestion in ruminants, and research on the impact of farming on the environment. Sheep are frequently used as a model for cattle and other large mammals, as they are smaller, less expensive to keep and easier to breed.
4. Sheep were used to develop a vaccine for Schmallenberg virus - a disease leading to deformities in offspring of sheep and cattle
In 2013, sheep were used in the development of a vaccine for Schmallenberg virus, a disease which causes deformities in the offspring of sheep and cattle. The vaccine was approved last year.
Before Dolly, frogs, mice and cows had all been cloned from the DNA of embryos. Dolly was remarkable in being the first mammal to be cloned from an adult cell after 277 attempts. This demonstrated that the DNA from adult cells, despite having specialised as one particular type of cell, can be used to create an entire organism.
6. Sheep do not have front teeth on their upper front jaw
7. Sheep have a 360-degree vision
Due to the position of their eyes, when their heads are down, sheep have 360-degree vision, meaning that they can see beneath their legs, and directly view whatever is behind them. (That said, we're pretty sure that the world's woolliest sheep, Shrek, pictured above, did not have 360 degree vision when at his fluffiest. We'd be surprised if he could see anything at all.)
8. A sheep was the first-ever hot air balloon passenger
While the use of unmanned hot air balloons can be traced back to ancient China, the first ever passenger-carrying balloon, named the Aerostat Réveillon, was launched on September 19, 1783, by the French Montgolfier brothers (a fantastically inventive pair, who later went on to launch the first-ever manned balloon flight). A basket attached to the Aerostat Réveillon carried a sheep named Montauciel, which translates as "climb-to-the-sky, and a duck and a rooster, neither of which appear to have been named. The flight, which lasted approximately eight minutes, covered two miles and reached a height of roughly 1,500 feet. Worried readers will be glad to know that all passengers, including Montauciel, were safely returned to Earth.
In 2007, a Swedish team successfully carried out womb transplants in sheep, leading to pregnancy. They worked on perfecting the technique of reconnecting the blood vessels and removed and replaced the uterus in individual animals. The womb has complicated connections to the blood supply and to the vagina, which must be successfully re-established for a transplant to work, and pregnancy puts an even greater strain on those connections. One of the biggest problems for clinical use of womb transplanting technology is the possibility of rejection during a pregnancy, because of the anti-rejection drugs.
Sheep can reduce water loss by using a heat exchange system in their brain to cool down their blood. The animal scan save up to 80% of their daily water intake by using this system. In a structure at the base of their brain, the artery with blood flowing towards the brain divides into many fine blood vessels. Heat from the arterial blood can transfer out of these fine vessels and into cooler venous blood flowing away from the brain, which can later be cooled by evaporation in the sheep’s nose. This cooling system doesn’t ensure protection against overheating of the brain but is actually a water-saving mechanism that works by cooling the hypothalamus, the body’s thermostat which is responsible for triggering panting and sweating when it’s hot.