When it comes to chicken, Doris Ma knows that bigger is not necessarily better.

On a recent Sunday morning, while most New Yorkers were still in bed, Mrs. Ma worked her way down a refrigerated display case at the Dynasty Supermarket on Elizabeth Street in Chinatown, eyeing poultry the way a drill sergeant might inspect his troops. She disregarded the shrink-wrapped oven stuffers and the plump skinless breasts, and instead directed her scrutiny to comparatively scrawny birds stuffed in plastic bags, heads and feet tucked beneath their wings.

The chickens, which the previous day had been wandering around a farm in upstate New York, wore white metal tags on their ankles with the name Bo Bo Poultry Market, in English and Chinese. At $1.69 a pound, they cost nearly twice as much as Hollyfield Farms' brawny broilers.

Asked why she would spend more for a chicken with less meat, Mrs. Ma scoffed, ''Even if you offered me American chicken for free, I wouldn't feed it to my family.'' Mrs. Ma, 47, a seamstress who emigrated from Canton, China, a decade ago, said brand-name poultry is raised on too many chemicals, and by the time it reaches supermarket shelves, it is several days old ''and has no flavor.'' And besides, she added, ''without the head and feet, it's worthless. If I can't look a chicken in the eye, I don't know where it came from.''

Such sentiments help explain why Bo Bo, a poultry business run by the Lee family, has exploded over the last decade. What started as a hobby, rearing egg-laying hens at the Lees' weekend retreat in the Catskills, has grown into a $10 million-a-year enterprise that now supplies 7 out of every 10 chickens sold in Chinatown, according to the company. Bo Bo is also expanding up and down the East Coast and planning to aggressively pursue customers who follow kosher and halal, or Muslim, dietary laws.