Girth (tack) strip down its center, it may cause discomfort. It is also best if it has some "give" to it, which makes it more comfortable for the horse. Many riders also choose a girth that allows for extra elbow room, so the horse is not restricted as his leg moves backward. To measure for a girth, the saddle with a pad should be placed on the horse. A measuring tape is then used to measure from the middle hole of the billet on one side, under the horse's belly, to the middle billet on the other side. If a girth is
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