The USDA gave two brands, Good Meat and Upside Foods, the green light last week to start producing and selling lab-grown, or cultivated, chicken in the United States. But is that kosher, literally?

The two companies tout their products as slaughter-free, raising a theological question: If meat doesn't come from a slaughted animal, does it still need religious oversight to be considered kosher or halal? The dietary restrictions followed by some Muslims and Jews both hinge on ritual slaughter. So is it even, from a religious, dietary perspective, really "meat?"

As is often the case with religious matters, there are a number of opinions, and a lot comes down to which religious leaders you follow and your level of observance. Some see the ability to grow meat from cells as a radical departure from traditional ways of harvesting meats, so radical that it throws certain tenets out the window. Others see it as requiring slightly different types of oversight.

But first, the practical perspective: Neither company has yet had its US-approved cultivated chicken product certified as halal or kosher. Upside Foods said it has not yet applied for certification, but that it ultimately would like to be available in markets where people largely keep kosher or halal. Good Meat said its products are potentially kosher but have not yet been certified, and that it is exploring the options for being certified halal.

From a philosophical perspective, only one thing is clear: It's complicated.

Religious and ethical vegetarians

Because cell-cultured meat is developed from animal cells, it's not considered vegetarian by Upside Foods or Good Meat. Those who don't eat meat for health reasons, or just because they don't like how it tastes, should stay away.

But people who don't eat meat for animal welfare or environmental reasons may want to give cultivated meat a try.

There are a number of ways to collect cells for cultivated meat that don't kill the animal, like through a biopsy, fertilized egg or even a feather.

That said, it is also possible for cells to be harvested from a recently slaughtered animal — if that's a concern, you might want to check the provenance of the cell with the producer before taking a bite.

In Hinduism, the practice of not eating meat stems from the concept of Ahimsa, or refraining from harm, which is important to many South Asian religions, noted Mat McDermott, senior director of communications at the Hindu American Foundation.

"As long as cultured meat is not derived from cells that are created or harvested from killing an animal, many Hindus would probably find that acceptable," he said.

Some who might be fine with cultivated chicken might shy away from cultivated beef.

"Given the reverence for the cow, [a biopsy] might cause an additional concern that probably wouldn't be there for chicken," said McDermott. Cows, which have particular symbolic significance, are considered sacred by many Hindus and may be treated with even more care than other animals.

Even if meat is made without harming the animal, some vegetarian Hindus might still abstain, McDermott noted.

"Vaishnava Hindus, like Hare Krishnas, however, cook and offer all our food in prayer first to God, Lord Krishna, as an act of devotion," said Anuttama Dasa, global communications director for ISKCON, the International Society for Krishna Consciousness.

According to the Bhagavad Gita, a foundational text for Vaishnava Hindus, meat products are considered offerable, he said. Because of that, cultivated meat "is still unclean ... and not to be eaten."

Halal guidelines

Kosher and Halal diets allow for the consumption of meat, with a variety of restrictions.

In order for cultivated meat to be considered halal, the animal that the cell lines originally came from would have to be halal and handled in a way that wouldn't make it haram, or forbidden according to Islamic law, said Mohammad Hussaini, vice president of global Halal affairs for the American Halal Foundation, a major halal certifier. That rules out pig products altogether.

It also requires animals to be slaughtered in a specific way, and forbids Muslims from eating meat taken from a living animal.

The last restriction poses something of a problem: If the cells from which cultured meat is developed come from animal biopsies, the resulting meat would not be considered halal, Hussaini said.

That would seem to rule cultivated meat out entirely. But, Hussaini noted, he spoke to a company that he did not name that would be open to taking cells from a recently slaughtered animal in order to secure Halal certification. Cell lines pulled from a dead animal could last years, so companies could justify the action as a one-time sacrifice that would open the door for halal consumers.

But there is another solution, Hussaini said.

Wool and feathers, which are not considered to be living parts of an animal, are considered halal, he explained. Good Meat says it can pull chicken cells from a chicken feather.

In addition to the animal cell being halal, every other nutrient used to help the cell grow needs to be considered halal, as well, according to Hussaini.

Kosher guidelines

Halal regulations have similarities to the Jewish laws of kashrut, which encompass kosher dietary restrictions. But one main difference is that kashrut forbids people from mixing meat with milk. In this case, the question of whether cultivated meat is considered meat, from a religious perspective, is significant.

For Rabbi Menachem Genack, CEO and Rabbinic administrator of OU Kosher, which has certified over one million products in 105 countries, the rules are straightforward enough: If the source is Kosher, the cultivated product is Kosher.

For cultivated meat to be considered kosher, it "would require that it came from a kosher slaughtered animal." Chicken that is grown from cells taken from a kosher, unfertilized egg would be considered kosher, he said. Gennack, like Hussaini, said that cells coming from a live animal would not be permissible. Neither would cultivated pork.

And mixing meat with milk? Not allowed. At least, not from the OU's perspective, though "there are different opinions," Genack acknowledged. Some say that cultivated meat could be considered "completely pareve." In Jewish law, pareve foods, such as fish, fruit and vegetables, are not considered meat or milk, and so can be consumed with either meat or dairy.

Israel's chief Ashkenazi Rabbi David Lau seems to be leaning in that direction.

In a January open letter addressed to Didier Toubia, co-founder and CEO of the Israeli cultivated meat company Aleph Farms, he outlined his position that a cultivated meat product could in theory be considered kosher and pareve, provided it is labeled as such.

But it might still be categorized as meat because it looks, tastes and smells indistinguishable from traditionally slaughtered meat. To avoid a situation where a Jew appears to be breaking Jewish law, a concept that makes certain technically permissible actions functionally forbidden in case they confuse an onlooker, the cultivated meat may be classified as meat.

Aleph Farms considers its product to be distinct from animal meat, Toubia told CNN. "We do see cells as a third category of animal products," he said. "I do believe it's not equivalent."

The company has been working with religious authorities in Israel, Persian Gulf countries and countries in Southeast Asia to try to ensure kosher and halal certification, he said.

"There's a mutual education, meaning we learn from the religious authorities, and we also need to educate them about the exact technology [and] what the options are," he said. There's an opportunity to "open new horizons in terms of the way tradition is looking at what we do."