Loos, the woman who claimed to have an affair with Beckham, spent 10 minutes stimulating Sam the boar in order to extract semen to inseminate sows on Tuesday night's show.
The Royal Society for the Prevention of Cruelty to Animals urged viewers to boycott the reality show, branding the incident "morbid and sordid".
TV watchdog Ofcom has received three viewer complaints as of yesterday, while Five has taken four calls about the incident.
The Sun newspaper conducted a reader poll today where 2,897 called the incident "disgusting" and 707 said it was "justifiable".
In a further blow to 'The Farm', former Stan Collymore quit the show last night after a series of rows with US rapper Vanilla Ice.
In the show, celebrities including Debbie McGee, former 5ive star Ritchie Neville, sex columnist Margi Clarke and TV presenter Jeff Brazier, live on and run a working farm. Terry Christian and Lady Victoria Hervey have already been axed from the show after public voting.
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