Companies throughout the food chain are changing the way they do business in response to soaring grain costs, and consumers are likely to bear the brunt in the form of rising food prices.

Farmers are making the broadest cuts to their livestock herds in decades, meaning meat at the supermarket will likely cost more in coming years. Middlemen are trying to shorten the duration of supply contracts to 90 days from one year so they can pass on higher costs more quickly. And food brands are shrinking the contents of their packages, from ice-cream cartons to beverage containers.

Before the grain markets stirred in the summer of 2006, the price of corn had stayed below $3 a bushel for a decade. In the space of two years it surged as high as $7 a bushel. Soybean and wheat made similar moves.

Global grain demand has outstripped production for much of this decade, draining supplies to unusually low levels. Strong economic growth in the developing world is giving hundreds of millions of people the means to afford richer diets, such as grain-fed meat. High oil prices on top of aggressive government mandates, meanwhile, are stoking production of corn-derived ethanol fuel. U.S. ethanol makers, while still struggling for profitability, are forecast to consume one-third of the corn now growing across the Midwest — double their appetite of just two years ago.

In the past month, the speculative fever has eased. The corn futures contract for September delivery rose 14.25 cents a bushel to settle at $5.22 a bushel Thursday. Still, the efforts by ranchers, bakers and meatpackers to shift the burden of higher grain prices show they think their raw-material costs aren’t returning to their old levels soon.