There are currently two methods for artificial insemination: bull semen can be frozen to a temperature of -172 °C and may be stored indefinitely.
However, pig semen must be diluted and stored liquid, and the storage capacity is only a few days. The window of opportunity for insemination is also limited. Striking the period when the sow is receptive is difficult and farmers need to inspect the animals regularly.
Achieving simpler insemination routines has therefore been an objective for Geno and Norsvin, the two national organisations that operate systematic rearing of cattle, horses and pigs.
“The timeframe from when a sperm dose for pigs is extracted until it must be utilised is five days,” says reproduction research scientist Ann Helen Gaustad at Norsvin. “Extending this by one to two days would be extremely significant.”
The two organisations contacted SINTEF in 2003 and with the assistance of funding from the Research Council of Norway a research project was commenced. Research scientists wanted to influence sperm cells to become capable of fertilising over a longer period. In 2008, the status is that the research scientists have developed a technique that moulds the sperm cells into an alginate gel. The cells can then be stored until the gel is inseminated into the animal.
“We have been trying to confirm a hypothesis that restricted tail movements of sperm cells, as is the case when they are in the animal’s testicles, provides longer lasting qualities,” says Geir Klinkenberg at SINTEF. “We achieve the restrictions by using the gel and the results to date are good. By achieving longer storage ability, it prolongs the lifespan of the sperm population in the uterus.”
Insemination sperm for pigs is currently sent throughout Norway from a central plant in Hamar. Norsvin produces up to 3000 doses daily.
“This is production on an industrial scale where the sperm can be utilised on a large number of animals, and where each sperm and each piglet represents high values,” says Klinkenberg.
The next step will take place in the spring with insemination trials on larger animals. Around 1000 animals will be inseminated using the new method to see if better results are achieved than with today’s conventional methods.
“This is a completely new and revolutionary approach where the focus has been on controlling the processes that occur both before and after the insemination,” says Geno Research & Development Manager Elisabeth Kommisrud.