"By the end of December 2015, the number of poached rhinos was 1,175," Environmental Affairs Minister Edna Molewa told reporters.
Fewer than 100 rhinos were poached in 2008, since when numbers have rocketed. A record 1,215 were killed last year.
The slaughter has been driven by demand for their horn in countries such as China and Vietnam, where they are prized for their purported medicinal properties.
The horn is composed mainly of keratin, the same component as in human nails, but it is sold in powdered form as a supposed cure for cancer and other diseases.
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Legally dehorning a rhino would see a farm owner put the animal under anaesthesia, then saw off the horn.
A South African judge in November lifted a domestic ban on trade in rhino horn, alarming conservationists.
The government appealed against the decision, but lost its latest hearing yesterday.
The case, bought by two game breeders, came ahead of a meeting in Johannesburg this year of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which could lift the global ban.
South Africa is said to be home to around 20,000 rhinos, some 80 per cent of the worldwide population.