Sen. Elizabeth Warren (D-MA) speaks to potential voters during a campaign stop at the Veterans Memorial Building on February 10, 2019, in Cedar Rapids, Iowa.

Democratic presidential candidate Sen. Elizabeth Warren of Massachusetts on Wednesday took aim at big agriculture and called for a break up of some recent industry mergers, charging "consolidation is choking family farms."

Lax merger enforcement has threatened the livelihoods of farmers and allowed agribusiness companies to become too large, the Democrat claimed in a policy post on Medium. It comes ahead of the Iowa Farmers Union's Democratic presidential candidate forum set for Saturday.

"I will appoint trustbusters to review — and reverse — anti-competitive mergers, including the recent Bayer-Monsanto merger that should never have been approved," Warren wrote.

Warren also criticized the Dow-Dupont and Syngenta-ChemChina deals, which involve mergers of companies supplying seeds and other products to farmers. She said industry consolidation and expansions of agribusiness giants have resulted in companies having "immense market power."

Dow, Syngenta and Bayer didn't respond to a request for comment.

Warren added, "My team will be committed to breaking up big agribusiness that have become vertically integrated and that control more and more of the market. Consolidation in agriculture is just part of a broader trend of consolidation that has hurt family farmers."

She also called out meat processing companies, saying four companies have a combined market share of 53 percent. Warren singled out food giant Tyson, which she said "controls just about every aspect of bringing chicken to market" and has meant "chicken farmers have gotten locked into a 'contract farming' system in which they take on huge risks."

Tyson Foods responded to the Warren's comment by defending the company's relationship with poultry producers.

"We're an American company, and we've been working with poultry farmers on a contract basis since the late 1940s and it has been a relationship we believe works well for both the farmer and the company," Gary Mickelson, a spokesman for Tyson said via email. "As noted on our website, contract farming insulates the farmer from the risk of changing market prices for chicken and feed ingredients such as corn and soybean meal, which represents the majority of the cost of raising chicken."

Additionally, National Chicken Council spokesman Tom Super told remarked, "The vast majority of America's chicken farmers are thriving and profitable. Chicken companies have waiting lists of people wanting to sign up to partner and raise chickens."

Earlier this month, the 2020 presidential contender called for the break up of big tech companies, including Amazon and Facebook.

According to Warren, "bad decisions in Washington have consistently favored the interests of multinational corporations and big business lobbyists over the interests of family farmers."

The Democrat said family farmers last year received "less than 15 cents" for every dollar Americans spent on food, making it the lowest amount since the government started tracking the data in 1993.

"Farmers are caught in a vise, but the squeeze on family farms isn't inevitable," she said. "We can make better policy choices — and we can begin by leveling the playing field for America's family farmers."

Rob Larew, a spokesman for the National Farmers Union — a group representing nearly 200,000 farmers and ranchers in 33 states — reacted to Warren's proposal Wednesday, saying: "It is really encouraging to see presidential candidates elevating this vital issue to family farmers and ranchers. For decades, we've allowed multinational corporations to gobble up competition in the markets that farmers and ranchers buy from and sell to."

The American Farm Bureau Federation, the nation's largest farm sector organization, however, brushed off Warren's criticism of big agriculture.

"Our membership hasn't shown much concern over current market structure," William Rodger, a spokesman for the national farm group said via email. "If they change their mind on the issue, you can be sure we will pay close attention."