TULSA, Okla. (AP) — Eleven poultry companies being sued for polluting a northeastern Oklahoma watershed persuaded a judge Wednesday to exclude portions of government reports purportedly describing problems associated with chicken waste in the Illinois River valley and what to do about it.

The reports were the first key pieces of evidence submitted by the state on the first day of testimony. State attorneys had planned to use the documents to show the poultry industry was largely responsible for pollution in the watershed on the Oklahoma-Arkansas border.

Attorneys for the defendants, which include Tyson Foods Inc. and Cargill Inc., argued the reports amounted to "political" documents aimed more at developing a legal strategy than providing scientific information to the public.

The objections came during early testimony from the first witness Oklahoma called in the case, former environmental secretary Miles Tolbert.

"It's self-serving hearsay," said Mark Hopson, an attorney for Tyson, who added that the reports were filled with disparaging — and unsubstantiated — comments about his client and the application of poultry litter.

Oklahoma Attorney General Drew Edmondson, who was questioning Tolbert, fought to admit the evidence, pointing out that the first report was commissioned by the previous governor and environmental chief before the lawsuit was filed in 2005.

But U.S. District Judge Gregory K. Frizzell agreed with several of the companies' objections, calling one of the reports "essentially a strategy of action" for the state.

Tolbert, who helped file the 2005 case on behalf of the state, will resume his testimony Wednesday afternoon.

He stepped down last year for a job in the private sector and his successor, J.D. Strong, is expected to testify later Wednesday or Thursday.

For decades, farmers in northeastern Oklahoma have emptied litter from their chicken houses and spread the droppings on their fields to grow other crops.

Oklahoma's lawsuit claims the hundreds of thousands of tons of bird waste spread on fields each year is one of the major causes of pollution in the watershed. It says runoff from the fields has polluted the Illinois River with harmful bacteria that threatens the health of the tens of thousands of people who raft and fish there each year.

The industry says it has acted responsibly and within the law in the way it handles poultry waste.

The outcome of the case is being closely monitored by other states thinking about challenging the way the poultry industry does business in other watersheds.

The other defendants named in the lawsuit are Cal-Maine Foods, Inc.; Tyson Poultry Inc., Tyson Chicken Inc., Cobb-Vantress Inc., Cargill Turkey Production L.L.C., George's Inc., George's Farms Inc., Peterson Farms Inc. and Simmons Foods Inc.

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