Los Angeles ? Sometimes, government inspectors responsible for examining slaughterhouse cattle for mad cow disease and other ills are so short-staffed that they find themselves peering down from catwalks at hundreds of animals at once, looking for such telltale signs as droopy ears, stumbling gait and facial paralysis.

The ranks of inspectors are so thin that slaughterhouse workers often figure out when “surprise” visits are about to take place.

These allegations were raised by former and current U.S. Department of Agriculture inspectors in the wake of the biggest beef recall in history: 143 million pounds from a California meatpacker accused of sending lame “downer” cows to slaughter.

The inspectors told The Associated Press that they fear chronic staff shortages in their ranks are allowing sick cows to get into the nation’s food supply, endangering the public. According to USDA’s own figures, the inspector ranks nationwide had vacancy rates of 10 percent or more in 2006-07.

“They’re not covering all their bases. There’s a possibility that something could go through because you don’t have the manpower to check everything,” said Lester Friedlander, a former USDA veterinary inspector at a plant in Wyalusing, Pa.

Amanda Eamich, a spokeswoman for the USDA’s Food Safety and Inspection Service, acknowledged the department has been struggling to fill vacancies but denied the food supply is at risk.

Similarly, Janet Riley, a spokeswoman for American Meat Institute, defended the meatpacking industry’s safety record. “It is interesting to keep in mind how heavily regulated we are,” she said. “Nobody has this level of inspection.”

Current and former inspectors and other industry critics charged staff shortages are also resulting in the mistreatment of animals on the way to slaughter and may have contributed to the recall announced earlier this week.

U.S. Sen. Herb Kohl, D-Wisconsin, said Thursday that his Senate Agriculture, Rural Development and Related Agencies Appropriations Subcommittee will hold a Feb. 28 hearing on the recall.

The USDA recalled the beef after the Humane Society of the United States released undercover video that showed slaughterhouse workers at the Chino-based Westland/Hallmark Meat Co. kicking and shoving sick and crippled cows and forcing them to stand with electric prods, forklifts and water hoses.