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Artificial insemination (AI), and accompanying hormone treatments given to female animals, have been successfully applied for decades. The next chapter in this success story has now been written, with the establishment of Ramsem’s new laboratory in Bloemfontein where sex-sorting of semen can now be done quickly and effectively.
This technology, says Dr Fanie Steyn, managing director of Ramsem, has the potential of taking the livestock industry to the next level. “The advantages of AI and synchronisation,” he explains, “are enormous and include aspects such as rapid genetic progress, higher lambing percentages, and shorter lambing and calving periods.
“Add to that the ability to determine whether you want male or female progeny from a particular female animal, and we’re talking a whole new paradigm. It represents an incredible leap forward for any breeder or producer.”
In years with good rain, such as this one, many producers are looking to rapidly expand their herds. This becomes possible by utilising sex-sorted semen instead of a 50/50 distribution between rams and ewes or heifers and bulls, to breed 95% ewe lambs or, if you are a ram breeder, 95% ram lambs.
“The same technology that has been available in the dairy industry for twenty odd years is now available in the meat industry, and can be successfully applied by cattle, sheep and goat producers. In another 20 years the industry would be unrecognisable.”
The process of determining gender
Semen is collected at Ramsem’s bull or ram stations and subjected to a rigorous evaluation process to determine motility, morphology and concentration. Next, the DNA is stained and sent through the machine which places it into one of three groups: male, female and unusable/dead sperm.
Selection is based on the number of DNA in each sperm. Female sperms consist of around 4% more DNA than male sperm, and the machine picks up this difference. The machine selects around 20 000 to 30 000 sperm per second.
“Once the gender has been determined,” says Fanie, “the client can decide whether he wants to collect the fresh semen for immediate use, or have it frozen for later use. Fresh semen has a better success rate than frozen semen – as much as 10 to 15% higher conception.”
The selection criteria for rams and bulls are very strict. Such an animal must have more than 65% progressive sperm and less than 15% primary abnormalities. Furthermore, the medium used for sperm dilution is also revolutionary new technology. It dramatically extends the shelf life of semen– a guaranteed shelf life of 72 hours after processing the fresh semen. However, it is recommended that semen be inseminated within 48 hours of processing.
Hormones for synchronisation
When synchronising sheep and cattle, whether for AI or to apply controlled mating, two hormones are involved, Fanie explains. One is progesterone and the other is pregnant mare’s serum gonadotropin (PMSG), or equine chorionic gonadotropin (eCG).
“Progesterone naturally occurs in the animal. Although we make use of synthetic progesterone, it has the same physiological action and effect as the natural progesterone in the animal. PMSG is a natural hormone that shortens the oestrus period and stimulates multiple ovulation. This hormone is purified from serum obtained from pregnant mares.
“There is no prescribed withdrawal period for any of these hormones if utilised in animals (this goes for both meat- and milk-producing animals). The reason for this is that when the sponge or controlled internal drug release (CIDR) device is pulled out of the animal’s vagina, the levels of progesterone released by the CIDR or sponge in the blood will decline within six hours, to such an extent that it no longer has any effect on the animal. The ewe or cow will therefore reach oestrus. Progesterone suppresses the animal’s cycle, and it only takes around 24 hours after having removed it for the animal to reach oestrus.”
The PMSG hormone works slightly longer. If the CIDR or sponge is removed, the animal is injected with PMSG. Ovulation occurs within 48 and 60 hours after the CIDR or sponge is removed, and by the time the animal ovulates, the PMSG is also completely removed from the bloodstream.
The effect of these hormones
Some circles have expressed concern that the prolonged use of hormones in female animals may ultimately have a negative effect on those animals. However, Fanie believes the opposite to be true in practice.
“What we’ve observed in the field is that, with improved management practices and nutrition, the lambing percentages of sheep producers who have been using these agents in their flocks for years are improving. This also applies to individual ewes. If there is resistance to the hormones which have built up over time, lambing percentages would tend to be lower, not higher.”
Of course, there is another factor that also comes into play when a producer begins to apply reproduction techniques, Fanie concludes, and that is the improvement in general herd or flock management. Along with the utilisation of these techniques, the producer is trained in all facets, from nutrition to herd health management, that will ultimately increase productivity.
“When utilising reproduction technology such as this, the benefits far exceed those already mentioned. Producers are simply becoming better managers. This generally means greater sustainability in the livestock industry.” – Izak Hofmeyr, Stockfarm
For more information, contact Ramsem on 051 412 6327 or visit www.ramsem.com.
