The US is losing a near-monopoly on exports of sorghum to the top importer, Mexico, which is already diluting its reliance on American corn by buying from South America.

Mexico's substantial cattle, hog and poultry operations, major corn importers, have increasingly switched to sorghum to meet their needs, in the face of elevated corn prices.

"High international corn prices provoked a rationing of feed and residual use corn demand, resulting in a strong shift to sorghum use in the feed ration," the US Department of Agriculture bureau in Mexico City said.

Some producers have experimented with rice byproducts as an alternative, although use of small grains such as barley and oats in feed is low, as a dearth of domestic production means livestock operations "are not familiar with them as ingredients in the feed process".

'More affordable prices'

The search for alternatives will reduce Mexican corn imports this season to a seven-year low of 7.70m tonnes – 800,000 tonnes below the USDA's official estimate - with only a shallow recovery expected in 2013-14, the bureau said.

But it will see sorghum imports reach 2.50m this season, 700,000 tonnes above the official USDA figure, with a further increase in 2013-14 to an 11-year high of 3.05m tonnes.

And this sorghum is being increasingly sourced from South America, with Mexico importing more than 200,000 tonnes of supplies from Argentina in January "due to more affordable prices" than US grain.

"Up to this point, Mexico had relied almost completely on sorghum imports from the US," the bureau said in a report.

The briefing cited hog producers in the north west of Mexico as leading the switch to sorghum, and to imports from South America.

Broader origins

Mexico's quest for alternatives to US sorghum supplies follows a broadening in its sources of corn imports, after last year's Midwest drought slashed America's exportable surplus of the grain.

The Mexican food safety authority, Senasica, in September published checks needed for buying corn from Brazil.

A month later, it was revealed that Mexican buyers had spurned the US for a 270,000-tonne corn import order.

Senasica is expected in the first half of this year to complete a risk analysis on corn imports from Argentina, sources told the USDA bureau.

Mexico was, in 2011-12, the second biggest corn importer, behind Japan, and biggest sorghum buyer.