Semen CollectionCollections of semen are normally done in the morning with around two collections per bull per day every second day in the peak of the season, and one to two collections three times a week during winter.
Bulls are allowed three 'loose' mounts of the steer which means the bull mounts the steer but semen is not collected. The loose mounts emulate what would naturally happen in the wild when cows tease ardent bulls, often walking away several times before standing for mating.
Two staff members are required to collect semen from a bull. One controls the bull while the other holds a rubber device known as an artificial vagina. This is shaped and constructed to resemble, as closely as possible, a cow's vagina. The handler places this at the same angle as the bull's penis; the penis feels the artificial vagina and thrusts through to ejaculate; the semen is collected.
The semen goes into a test tube at the end of the artificial vagina. The quantity is immediately recorded and the vial labelled before it goes to the laboratory for processing.
Semen ProcessingImmediately the collection arrives in the laboratory it undergoes a series of international standard tests - for sperm quantity, volume (number of live sperm) and quality (sperm of the correct shape and size.
Sperm are very sensitive to changes in temperature and are slowly cooled to room temperature before they are stored in liquid or frozen straws. Information is printed on the straws giving the name of the bull, its official number, breed and the batch number of the ejaculate prior to the straw being filled.
Semen TechnologyResearch into storage and lengthening the life of sperm so it can be used for artificial breeding began in the mid 1930s. In 1949 English scientist, Dr C Polge, discovered the cryoprotective effect of glycerol, for the first time cooling and freezing sperm to -70 degrees C.
Prior to this time artificial insemination trials had been going on in New Zealand (beginning in 1935) dealing with fresh semen but, because of problems collecting semen and inseminating cows, conception rates were low.
In 1939 Dr John James (who qualified at the London Veterinary School in December 1937) began intensive study (and field trials) into artificial breeding concentrating on collection, dilution and storage of semen.
By 1954, when Dr Pat Shannon started working for the artificial breeding centre (which was to become LIC) around 25 million sperm were contained in each insemination. There had to be such a high number because sperm died off quickly when exposed to oxygen.
The challenge for Pat and his team of researchers was to find out how to keep them alive longer and to dilute them further to get more inseminations from the best bulls. The answer was a diluent, now known as Long Last Liquid™, which reduced the number of sperm per insemination from 25 million to 1-2 million sperm, without loss of fertility.
The effect of that technology had a marked effect on the number of inseminations which could be collected from top bulls: In the 1950s bulls averaged 10,000 inseminations per year; Long Last Liquid™ meant LIC could now get around 250,000 inseminations per bull per year!
LIC's Long Last Liquid™ (LLL) means the company is able to obtain more straws of semen per ejaculate than any other artificial breeding company in the world.