(CNN) From suggestions for members of a science committee to emails sent "on the sly" and thoughts for the secretary's speeches, new internal emails from the US Department of Agriculture show big food industry lobbyists are working hand-in-glove with agency staffers.

The newly released emails were obtained by the nonpartisan independent Project on Government Oversight via a Freedom of Information Act request and shared exclusively with CNN. Though exposing no apparent legal violation, they offer a window into how some top USDA political appointees -- former lobbyists themselves -- are in frequent contact with their old employers and others who are lobbying the agency, and how those lobbyists are seeking to influence the agency on issues large and small.

The USDA, under the Trump administration, has moved to roll back a series of regulations opposed by industry, to the chagrin of health and food safety advocates. The emails show how the agency is very willing to work with industry lobbyists, even accepting and using talking points for one of Secretary Sonny Perdue's speeches.

Perdue speech

In January, a representative from the lobbying group National Grocers Association sent a USDA official talking points for a speech the secretary would give to the group the next month.

"We're thrilled that Secretary Perdue will be speaking at the NGA Show in a couple of weeks. In advance of his speech during our opening general session on Sunday February 11 I wanted to share a few themes that may be appropriate for him to mention given the audience that will be in the room," wrote Greg Ferrara, executive vice president of public affairs for the association.

The email was sent to USDA policy adviser and former industry lobbyist Kailee Tkacz. She responds, "Thank you for sending this along, will get to our comms team and keep you posted. Good stuff!"

Four days later, Perdue's speechwriter emailed Ferrara at the National Grocers Association, "Greg, I am working on remarks for Secretary Perdue for the NGA show. I would like to talk with you for a few minutes about the event. Kailee forwarded your e-mail with suggested themes. Is there a good time to give you a call and what is best number? Thank you for your help."

Among the talking points offered by Ferrara is a discussion of how rural grocers "are often the only food store for miles in rural America, committed to sticking it out, not because they are getting rich, but because they live in these communities and know without a grocery store the community will suffer. They are not driven by Wall Street, but rather by Main Street and are an essential part of what makes American great."

In his February speech to the association, Perdue echoes the talking points, telling the grocers that "your stores many times are the only stores available for food for miles around, and we don't acknowledge that very often, but I ... appreciate you sticking it out. I appreciate you sticking it out not because you are certainly getting rich in doing that, I understand that you're not ... there for the money, you're living there because you know it is supportive to the community ... you're not driven by Wall Street, certainly, you're driven by Main Street, and you are making a difference there where you serve."

USDA Communications Director Tim Murtaugh told CNN by phone that "in that case, the speechwriter liked the phrasing and the rhetoric there and just elected to use it." Asked whether that's a normal practice for the agency's speechwriter, Murtaugh added, "What's the big deal? It's just the description of the role of small grocer stores."

In a written statement Murtaugh added that "it is a common practice among speechwriters the world over to gather information from the organizers of events, including specific topics of interest, to be incorporated into prepared remarks. In one passage highlighted by CNN, the speech merely employed complimentary language that the National Grocers Association uses to describe its own members."

The National Grocers Association told CNN that providing these types of talking points is "normal practice," it does this "as a courtesy for most speakers who address our organization" and said "how a speaker uses the background information ... is entirely up to their discretion."

But Republican speechwriter Landon Parvin, who has written for Presidents Ronald Reagan, George H.W. Bush and George W. Bush, discussed the email and the speech with CNN and said the practice is not normal.

"I wouldn't say it's normal," Parvin said. "I would worry about the optics. The optics aren't good."

Parvin explained that groups traditionally do discuss topics of interest with the speechwriter, but he says sentences in a Cabinet secretary's speech should not closely mirror those found in lobbyists' talking points. "You don't want to get the speaker in a situation where it looks like they are quoting a lobbyist."

Roughly 10 minutes of Perdue's 23-minute speech paralleled the lobbyist talking points. Perdue paraphrased most -- but not all -- of the themes the lobby group laid out in its talking points.

The speech also included portions that did not come from the talking points about the administration's agenda.

Ethics groups say the agency should be deciding what the secretary says in his speeches -- not industry.

"The federal government should be creating the talking points for a Cabinet head, not a trade association. This makes it look like the agenda is being set by lobbyists," said Norm Eisen, of Citizens for Responsibility and Ethics in Washington. "President Trump ran on draining the swamp, but government agencies are continuing to pursue the special interest agenda. This is a profound betrayal of Trump's drain-the-swamp promise."

Sodium and potassium committee

Another email exchange shows USDA officials and industry representatives discussing the names of people whom industry would like to see serving on a committee looking into the health effects of consuming sodium and potassium. The emails show industry's behind-the-scenes efforts to influence the outcome of a critical study, and the USDA appearing receptive to the industry's influence.

The National Academies of Sciences, Engineering and Medicine has formed a 14-person committee to study how much salt and potassium is safe for Americans to eat. The study is known as the review of the Dietary Reference Intakes for sodium and potassium. The USDA is one of six sponsors for the committee and its study.

Emails from late January show that USDA official and former industry lobbyist Tkacz, other top USDA appointees and a team from Food Directions, which has lobbied for the National Restaurant Association and Grocery Manufacturers Association, got together for an in-person meeting. Following that meeting, the group's senior director of food policy writes to USDA'S Tkacz, "As promised, attached to this email is the list of potential names and bios, all of whom, we feel, would bring more balanced perspectives to the DRI committee in order to ensure robust debate of all of the science. This updated list includes the two additional names I mentioned in the meeting."

The industry has complained there aren't enough industry voices on these sorts of advisory panels. The email suggests the lobbyist is seeking USDA support for particular industry-friendly candidates for the committee.

Marion Nestle, visiting professor of nutritional sciences at Cornell, says she's not surprised by the email communications: "We have a very industry-friendly government right now."

Nestle says sodium is a controversial topic in the food industry: "Salt is in junk food. It's in restaurant food. The industry has a vested interest in having salt in the food supply." But their interests may be at odds with public health interests. Nestle says for that reason "it's important to keep industry out of scientific advisory committees about diet, because industry has a vested interest."

The National Academy of Sciences said in an email, "Suggestions can come from any interested party, so it is possible for sponsors to submit recommendations," but would not say specifically whether USDA had done so, noting that "details regarding committee nominations received are kept confidential."

CNN asked whether the USDA recommended any of the 14 individuals currently studying the issue. USDA Communications Director Murtaugh told CNN, "No one from the list was recommended for the committee by USDA, and none of them was named to the committee."

The 14 people currently serving on the committee all appear to be either scientists or academics.

The National Academy of Sciences says on its website that "a committee is not finally approved until a thorough balance and conflict-of-interest discussion is held at the first meeting and any issues raised in that discussion or by the public are investigated and addressed."

CNN reached out to Tkacz. The USDA responded on her behalf, saying the agency "did nothing" with the industry-provided list.

But Nick Schwellenbach, director of investigations at the Project on Government Oversight, finds the email from Food Directions troubling.

"It's still an industry attempt to influence the committee's makeup and the scientific advice it would ultimately provide. But the attempt likely happened too late after the die had been cast and membership was decided," he said.

The snack industry

On January 9, Tkacz, a former director at SNAC International, the international trade association of the snack industry, wrote an email marked "high" importance to Jessica Hixson, a lobbyist with SNAC, Tkacz's former employer. "I have a random question for you," the email starts. Tkacz explains that Perdue might be traveling near Snyder's and Utz facilities in the coming weeks in Hanover, Pennsylvania. Snyder's of Hanover is a snack food distribution company and Utz is, according to its website, the largest independent, privately owned snack brand in the United States.

Tkacz wrote, "I am trying to put in the plug in he should pop by one or both of these facilities for a tour. I don't want to get everyone excited at the companies yet in case it doesn't happen, but I am curious if you could on the sly get me data on their export numbers so I can make the case for the Secretary to visit?"

Later in January, Perdue headed to central Pennsylvania to promote the farm bill. He made a stop in Gettysburg, Pennsylvania, which is a short distance from Hanover, but the agency says he did not end up visiting Snyder's or Utz.

Karen Perry Stillerman, with the Union of Concerned Scientists, says the email illustrates a USDA employee working behind the scenes with her former employer in what looks like a "blatant intervention on behalf of companies Tkacz once lobbied for."

Ethics experts point to a law that says government employees are required to "act impartially and not give preferential treatment to any private organization or individual."

The agency's communications director defended the emails: "When planning the Secretary's trips to states, it is common for USDA staff to contact agriculture-related businesses in order to consider them as locations to visit."

Ed Schafer served as USDA secretary under President George W. Bush. While he doesn't believe the email communications between the two were an ethical violation because he doesn't see a potential visit providing economic gain for the companies, Schafer told CNN, "I would prefer if my trips were not arranged involving lobbyists. I'd prefer my staff to consult with and arrange trips through local USDA offices and state agriculture departments."

Schafer said relying on state and local governments over lobbyists is the preferred way to operate because lobbyists have narrow agendas.

The USDA, again responding on behalf of Tkacz, said she "was familiar" with the Snyder's and Utz locations because she came to USDA "with knowledge she learned while working elsewhere" and that she is complying with ethics rules, so "there is no conflict of interest."