Cloned Animals
Animal cloning
Cloning is the most recent evolution of selective assisted breeding in animal husbandry. Cloning animals is a reliable way of reproducing superior livestock genetics and ensuring herds are maintained at the highest quality possible.

How successful is it?
Cloning animals through somatic cell nuclear transfer is simply inefficient. The success rate ranges from 0.1 percent to 3 percent, which means that for every 1000 tries, only one to 30 clones are made. Or you can look at it as 970 to 999 failures in 1000 tries.
Here are some reasons: ▪ The enucleated egg and the transferred nucleus may not be compatible ▪ An egg with a newly transferred nucleus may not begin to divide or develop properly ▪ Implantation of the embryo into the surrogate mother might fail ▪ The pregnancy itself might fail

Problems
Cloned animals that do survive tend to be much bigger at birth than their natural counterparts. Scientists call this "Large Offspring Syndrome" (LOS). Clones with LOS have abnormally large organs. This can lead to breathing, blood flow and other problems.

Can cloning save endangered animals?
Scientists usually have a poor understanding of endangered animals' reproductive physiology, which makes it too risky to extract a sufficient number of eggs from that species or rely on females of that species to give birth to clones.

What animals were first cloned?
Over the last 50 years, scientists have conducted cloning experiments in a wide range of animals using a variety of techniques. In 1979, researchers produced the first genetically identical mice by splitting mouse embryos in the test tube and then implanting the resulting embryos into the wombs of adult female mice. Shortly after that, researchers produced the first genetically identical cows, sheep and chickens by transferring the nucleus of a cell taken from an early embryo into an egg that had been emptied of its nucleus.It was not until 1996, however, that researchers succeeded in cloning the first mammal from a mature (somatic) cell taken from an adult animal. After 276 attempts, Scottish researchers finally produced Dolly, the lamb from the udder cell of a 6-year-old sheep. Two years later, researchers in Japan cloned eight calves from a single cow, but only four survived.
Animal cloning https://www.bio.org/sites/default/files/Cloning_onepager.pdf How successful is it? http://learn.genetics.utah.edu/content/cloning/cloningrisks/ Problems http://learn.genetics.utah.edu/content/cloning/cloningrisks/ Can cloning save endangered animals? http://www.scientificamerican.com/article/cloning-endangered-animals/ What animals were first cloned?
https://www.genome.gov/25020028#al-7