The 56-year-old woman is believed to have suffered an epileptic seizure while feeding the animals, Russian state media reported.
She is said to have suffered severe bites to her face, ears and shoulders and died of blood loss.
The woman was found by her husband early on 1 February at their farm in a village in the Malopurginsky district of Udmurtia, western Russia.
He had gone to bed early because he felt unwell and did not find his wife until the next day, according to Moscow-based news website Newstes. It did not say how many pigs were in the sty.
Officials have launched an investigation into the incident, Russian media reported.
It is not the first time a farmer has been consumed by his own pigs. A man in the US state of Oregon was eaten by his animals in 2012.
Authorities found Terry Vance Garner's dentures and pieces of his body in the enclosure in which he had been feeding the livestock.
Investigators said the 69-year-old may have been knocked over by the 50-stone animals before they ate him.
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