More ostriches on seven farms in the Klein Karoo valley in the Western Cape are to be culled after the areas tested positive for avian influenza.
"Ostriches on those farms are also going to be culled by way of controlled slaughter in the abattoir," the agriculture department said on Tuesday.
The skin and feathers would be harvested and processed, and the meat turned into pet food.
The move follows a recent outbreak of the virus in the province. It saw the department isolate a highly pathogenic avian influenza in the Klein Karoo last month and led to the immediate suspension of ostrich meat exports to the European Union (EU).
"A total of 10,000 ostriches have already been culled in this way during the current outbreak, and the department at this stage cannot estimate the total number that will be culled, since the outbreak is on-going," the department said in a statement. "More farms are being sampled and more results becoming available from the laboratory. This remains part of the outbreak and should not be viewed as a different outbreak." The entire Klein Karoo valley, which represents about 70 percent of the ostrich industry, is affected and no movement of ostriches is allowed except to the abattoir.
The department said this measure was a bid to contain the outbreak and prevent it from spreading to other areas.
The rest of the country could, however, move birds for slaughter for the local market if the farm of origin had tested negative within 28 days of slaughter.
"The impact in the Klein Karoo valley is quite serious as this is the hub of ostrich production and the economy of the area is based on this," the department said.
It was working with the industry to alleviate the socio-economic implications of the outbreak.
"The department hosted a team of experts last week from the EU, whose mission was to assist and not to inspect the control measures put in place [and] a report following this visit is awaited.
"The department wishes to convey its gratitude to the Western Cape veterinary authorities and the industry for the support in an effort to eradicate this disease before it affects the country's poultry population."