Another feature of Dr. Farrell's system that appealed to BLM personnel was the humane way in which the identification was applied to the animal. Instead of the age-old, painful method of branding with a hot iron, the identification is freeze marked on the animal using copper marking rods dipped in either liquid nitrogen or dry ice and alcohol. Unlike branding, freeze marking produces no open wound to become diseased or infested with insects. As a BLM range conservationists describes the technique, "the animal feels no more pain than a person does when his tongue sticks to a cone of ice cream."

The bars and angles in the Alpha Angle system are easily translated. The corners of a basic square represents the even numbers in the system. The number two is represented by the upper left hand corner of the square, the numbers 4, 6, and 8 are represented by the remaining angles moving clockwise from the angle representing the number 2.

Next the basic square is overlaid with a square tilted at a 45 degree angle. Odd numbers are now represented by the angles between the angles of the basic square. Two verticle lines represent the number 1; two horizontal lines represent

zero.

To be fully operable, the Alpha Angle method requires only a single marking rod with a right angle engraved on one end and a straight line on the other.

Before the animal is freeze marked, the area to be marked is shaved and washed with alcohol to withdraw body heat and to aid in the conduction of the intense cold. The cold copper stamp destroys pigment producing cells, and hairs growing back in the area are white. Applying the copper stamp longer than 10 to 20 seconds results in more balding which is necessary for producing legible marks on white or light-colored animals.

BLM officials were convinced, after tests at several holding corrals where animals awaited adoption, that they had found in the Alpha Angle system the most practical and humane method of identification. Subsequently, on April 1,

1978, the uniform marking procedure was implemented. Every wild horse and burro adopted after that date would wear a stylized "U" designating it as a wild horse or burro belonging to the United States. Each animal would also be marked in Alpha Angle code, with a number assigned to it on the national registry at the Adopt-a-Horse headquarters in Denver.

Simultaneously with the start of the uniform procedure, steps were taken to make the public aware of the system. Notification sent to brand inspectors, horse and burro protection organizations, groups of

horse and burro fanciers, humane societies, agricultural extension agents, and regional offices of the national crime information network run by the Federal Bureau of Investigation. Most of these groups received posters for their use.

The media publications relating to horses and burros, in particular also were alerted to the new identification system procedure. Each received a diagram of the Alpha Angle method of marking, as well as instructions on translating the angles and bars into numerals that would identify the particular animal.