The smallstock stud industry in South Africa is plagued by the illegal use of steroids to artificially boost animal growth. But these drugs damage the growth and fertility of the animals and their offspring, and buyers wind up paying for genetic merit that isn’t really there. Annelie Coleman discussed the issue with head of the department of Animal, Wildlife and Grassland Sciences at the University of the Free State, Prof Johan Greyling.
Despite all their potential to cause damage, anabolic steroids are still being used to increase growth and improve performance in livestock.Steroids are particularly administered to rams, raising auction prices for so-called “superior” animals. But once the farmer puts the animal on veld, it falls apart.These steroids have also been known to cause reproductive disorders such as reduced semen production and an irregular oestrus cycle in ewes. “The improved performance obtained with anabolic steroids doesn’t reflect the true genetic growth potential of the animal,” explains Prof Johan Greyling of the University of the Free State. “It’s illegal and even dangerous.”
Drugs of choice
Of the steroid hormones currently in use, the most common are Laurabolin for veterinary use and Deca Durabolin for human use. Laurabolin, for example, can stay active in the body for up to four weeks. Both contain nandrolone, which is strongly conducive to muscle development resulting in perceived better conformation.
Both also cause masculine traits as a side-effect, because of their high testosterone content. They can cause the cardiac muscle to expand, potentially causing heart attacks, and damage major organs. The liver is particularly susceptible because it breaks down the compound.
Growth – with constant feeding
Body growth is biologically complex. It involves the interaction of hormones, genes, nutrition and metabolic factors. Anabolic steroids enhance growth, but this can only be maintained with constant energy intake. They increase nitrogen retention and the deposit of proteins in the body. This increases the muscle to fat ratio. It also improves feed conversion ratios, in conjunction with high concentrate or so-called energy diets.
“Interestingly, on natural veld, even if there is no growth response the steroids reduce scrotal circumferences,” explains Prof Greyling.
Slashing male fertility
Steroids’ possible negative affect on male fertility is worrying. The body can’t distinguish the artificially supplied testosterone from the testosterone it produces itself.When the body detects an elevated testosterone level in the blood, it doesn’t recognise it as artificially induced, and the testes decrease testosterone production. This decreases testicle and scrotal size.“Trials have shown a 7% to 15% increase in body weight in a variety of breeds over a three-month treatment period after weaning,” explains Prof Greyling. “But scrotal circumference and volume decreased 25% to 51% in six- to nine-month-old lambs. “The young age at which the animals were treated could have increased the response. The tests were done to determine fertility traits such as semen quantity and quality, as well as sex drive or libido.
Key roleplayers in the smallstock industry have resolved to conduct “dope tests” at certain shows and auctions, in a similar manner to the testing of athletes. This would identify animals illegally benefiting from drug treatment. The main objective of the testing would be to protect buyers. “The use of anabolic steroids must be eliminated in animal breeding,” says Prof Greyling. “Irrespective of the cost, we should test the top three animals in each category or the most expensive animals at auctions.”
“Using any growth promoters or stimulants, which are generally a combination of sex hormones, should be strongly denounced for breeding purposes.”
Prof Greyling is adamant steroids not only damage livestock, but also impair reproduction and distort the performance of the progeny. Whoever is illegally dispensing the steroids to breeders is also complicit. Most anabolic steroids are only available on prescription. This means their use could implicate a guilty party in the veterinary profession. Contact Prof Johan Greyling on (051) 401 2211. |fw