Host Seth MacFarlane speaks at the 85th Annual Academy Awards on Sunday in Hollywood, California. [Photo/Agencies]

Critics blasted Oscars host Seth MacFarlane on Monday for "crudely sexist antics" and peddling "offensive" Jewish stereotypes, as the Academy Awards post mortem got into full swing.

Others said the Family Guy creator, brought in to appeal to younger viewers with edgy humor, was simply dull - while satirical website The Onion had to apologize for an expletive tweet about the youngest ever Oscar nominee.

"Well, that didn't work," wrote the Los Angeles Times' television critic at the start of a full-page review of the more than three-hour 85th Academy Awards telecast on Sunday night.

"Despite the valiant efforts of Adele, Barbra Streisand and a surprisingly witty Daniel Day-Lewis ... (the show) was long, self-indulgent and dull even by the show's time-honored dull-defining standards," she wrote.

MacFarlane, also the creator of potty-mouthed bear star Ted, was part of the latest attempt by the Academy of Motion Picture Arts and Sciences to shed its old-fashioned image, while maintaining its Tinseltown prestige.

Indeed, the opening segment of the show riffed on whether MacFarlane would do a good job as Oscars host - with Star Trek star William Shatner appearing in character by video link from the 23rd century, to tell him how badly it had gone.

Critics said the section was too long and too self-referencing, and they notably blasted a song called We Saw Your Boobs, which listed the actresses who had appeared topless on screen.

"Watching the Oscars last night meant sitting through a series of crudely sexist antics led by a scrubby, self-satisfied Seth MacFarlane," wrote culture bible The New Yorker.

"That would be tedious enough. But the evening's misogyny involved a specific hostility to women in the workplace. It was unattractive and sour."

A sketch with Ted provoked some of the harshest criticism. The bear appeared with his big-screen buddy actor Mark Wahlberg, and made a series of jokes about having sex with audience members and an orgy at Jack Nicholson's place.

He then joked about Jewish control of the US movie industry, saying his real name was Theodore Shapiro, adding: "I would like to donate money to Israel and continue to work in Hollywood forever. Thank you."

The Anti-Defamation League, an anti-Semitism watchdog, blasted the jokes as "offensive and not remotely funny".

"It only reinforces stereotypes which legitimize anti-Semitism. It is sad and disheartening that the Oscars awards show sought to use anti-Jewish stereotypes for laughs," said ADL national director in the US, Abraham Foxman.

"For the insiders at the Oscars this kind of joke is obviously not taken seriously ... But when one considers the global audience of the Oscars of upwards of 2 billion people, there's a much higher potential for the 'Jews control Hollywood' myth to be accepted as fact."

In a separate row triggered by the Oscars, The Onion apologized Monday for using an offensive sexually charged word to describe nine-year-old Quvenzhane Wallis, the youngest ever best actress nominee for Beasts of the Southern Wild.

"On behalf of The Onion, I offer my personal apology to Quvenzhane Wallis and the Academy of Motion Picture Arts and Sciences for the tweet that was circulated last night during the Oscars," said Onion chief Steve Hannah.

"It was crude and offensive - not to mention inconsistent with The Onion's commitment to parody and satire, however biting," he said.