Google’s YouTube is getting ready to say bye-bye to some losers.

The search giant that kicked off an ambitious plan last February to establish dozens of professionally produced channels — most of which received some of the $100 million in initial funding handed out by the video-streaming site — is now looking to cut some of the less successful channels from its game plan.

“They’ll cull the herd and work with the best,” said one source who suggests YouTube execs will be deep in discussions on its original-content initiative 2.0 plan over the next few weeks — and that the ax will fall on the less popular channels before Dec. 31, The Post has learned.

Along with the decision on which channels to cut will be a new round of funding for new channel startups.

“By October or November they’re going to be deciding on new people to fund,” said one channel partner, who noted that by then YouTube will have had nine months to see what’s working and will move on to fund new channels as it hones in on the most lucrative models.

The weeding out of the less-popular videos comes amid a new emphasis at YouTube on the time viewers spend on the channel — and not just how many views each channel gets. YouTube is also looking to upgrade the quality of its videos and tweaked its algorithm in April to help the move.

“If a channel has 20 million views, and viewers spend just 35 seconds on the channel, how valuable is that to an advertiser?” one partner asked.

Youtube CEO Salar Kamangar is putting fresh emphasis on quality and it looks to be boosting numbers. Since January total hours watched on YouTube jumped 33 percent to 4 billion from 3 billion.

YouTube made the move in February, in part to get ready for when a significant percentage of TVs across the country are Web-connected.

One person familiar with YouTube’s 2.0 strategy said the site was moving from a shotgun approach to more of a sniper approach. The next phase will also include $200 million for online ads to promote the channels.

Among the higher-ranked original-content channels on YouTube are The Warner Sound, produced by Warner Music, and the Reserve Channel, a lifestyle and travel-focused effort.

Reserve, which debuted in July, airs a show featuring Eric Ripert, the chef at LeBernardin, with guests so far like Anthony Bourdain, Mario Batali and Stanley Tucci. A second show is hosted by Savannah Jane Buffett, daughter of singer Jimmy Buffett, focused on the exotic lifestyles of ex-pats.

Citigroup analyst Mark Mahaney estimates YouTube will draw $3.6 billion in revenue this year, up 50 percent from 2011. YouTube has signed a host of advertisers that are spending upwards of $1 million a year at the site. Among big spenders are American Express, GM, Unilever, Gillette, Toyota and Hasbro.