Opening calls are steady to slightly lower for grain futures after a weaker close on Friday. Weekend rains in Argentina may keep the bulls in check along with possible pressure on energy prices. A potential source of support could come from further decline in the dollar’s value and from related strength in grain export demand. In the Headlines Grains closed lower on Friday but still held gains for the week. March corn futures were up 2 1/4 cents over the four sessions that made up the shortened holiday week. March beans were up 21 3/4 cents. The nearby Chicago wheat contract was up 5 1/4 and the March Kansas City up 11. February live cattle jumped $8.02 and January feeders finished higher by $5.20. February hogs were up $1.17. Soy futures felt pressure from news that Argentina was lowering its export tax through at least June. Despite facing drought throughout the current growing season, Argentina is still set to produce enough so that it remains the world’s top exporter of soy meal. Cuts to Argentina’s crop estimates can still be price friendly down the road, since USDA last predicted the Argentine soybean crop at 52 million metric tons versus what…