(Adds Rio Grande, Itajai ports, poultry plant closures, farmers' fuel survey)
By Marcelo Teixeira
SAO PAULO, Feb 27 (Reuters) - Striking truckers lifted their blockade of dozens of highways in Brazil on Friday after police began fining and arresting protesters who have slowed grain deliveries in the commodities powerhouse.
Road blockages were reported at 59 locations across six states on the 10th day of the strike, down from the Thursday count of 88 road blocks, according to highway police.
The strike caused temporary closing of 60 pork and poultry plants, reducing the country's slaughter by 50 percent and causing some companies to default on export orders, said the president of the Abpa industry group, Francisco Turra.
"They don't have access to corn or soymeal. Chickens are going hungry ... Cannibalism has started," Turra told Reuters.
Protesters also blocked access to the main pork and poultry exporting port of Itajai, the port spokesman said.
But silos at Paranagua, Brazil's second-largest port for soy exports, now have enough soybeans to keep filling ships until March 3, rather than March 2, after more trucks arrived on Friday, port spokeswoman Ceres Battistelli said.
Since the protests began, Chicago Board Of Trade March soybean prices have risen nearly 4 percent on fears of supply disruptions in Brazil, the world's No. 2 soy producer.
Highway police said 26 fines had been issued and one person was arrested.
Further south, the port of Rio Grande is receiving about half the corn and soybeans it usually does this time of year and could run out of soy stocks this weekend, a spokesman said.
News web site G1 showed police firing tear gas at protesters in Rio Grande do Sul state, where the port is located, a sign that authorities are clamping down on a movement that will likely result in higher food prices and pressure inflation.
The government has yet to sufficiently address protesters' concerns over high diesel prices and rising freight costs, the national autonomous transport federation president Diumar Bueno told Reuters.
In top soy growing state Mato Grosso, failure to secure fuel deliveries threatens to further delay soybean harvesting. The state's harvest was 53.6 percent complete as of Thursday, down from 58.5 percent at the same point last year, said farm institute Imea.
An Imea poll of soy and cotton farmers showed 60 percent of farmers have diesel fuel supplies to run farm equipment until Monday, while 20 percent have already run out. The institute sent surveys to 5,000 producers, though only 10 percent responded. (Additional reporting by Roberto Samora, Reese Ewing, Leonardo Goy and Caroline Stauffer; Editing by Todd Benson, W Simon and Gunna Dickson)