An appeals court upheld the sentence of Jacques Els, 39, from Thabazimbi in the extreme north of the country, according to the Afrikaans-language Beeld newspaper on Wednesday.
He was convicted in March for buying 30 horns for 760,000 rands ($94,000, 74,000 euros) from Tommy Fourie, the manager of another game farm.
Els was arrested in October 2010 and and later sentenced for transporting the horns without a permit. They had been cut from drugged rhinos. Fourie committed suicide a month later.
Els was handed a suspended sentence for the illegal possession of eight horns from his own rhinos.
He has to pay one million rands to the country’s environmental police as part of his sentence.
The farmer was arrested after the appeals court verdict Monday, but lawyers are trying to extend his bail pending a petition against this sentence.
Nearly 270 rhinos have been slaughtered in the country since the start of this year.
With roughly 20,000 animals South Africa is home to between 70 and 80 percent of the world’s rhinoceros population, increasingly being targeted by poachers despite heightened security.
Last year poachers killed 448 animals compared to 333 in 2010. In 2007 only 13 animals fell prey to illegal hunters.
The animals’ distinctive horns are hacked off to be smuggled to the lucrative Asian black market, where the fingernail-like substance is falsely believed to have powerful healing properties.
On the black market, the horns fetch almost 50,000 euros ($62,700), or the same price as an ounce of gold, according to several experts.