Saddle Saddle The saddle is a supportive structure for a rider or other load, fastened to an animal's back by a girth. The most common type is the equestrian saddle designed for a horse. However, specialized saddles have been created for oxen, camels and other creatures. It is not known precisely when riders first began to use some sort of padding or protection, but a blanket attached by some form of surcingle or girth was probably the first "saddle", followed later by more elaborate padded designs. The solid saddle tree was a later invention, and though early stirrup designs predated the
Animal testing on rodents Epigenetics, and the Inescapable Problem of Animal Constraint. Animal Models of Behavior Genetics, (Springer, 2016), pp. 265–301. Animal testing on rodents Rodents are commonly used in animal testing, particularly mice and rats, but also guinea pigs, hamsters, gerbils and others. Mice are the most commonly used vertebrate species, due to their availability, size, low cost, ease of handling, and fast reproduction rate. In the UK in 2015, there were 3.33 million procedures on rodents (80% of total procedures that year). The most common species used were mice (3.03 million procedures, or 73% of total) and rats (268,522, or 6.5%). Other