Sales at sausage maker Cranswick sizzled higher, but the group said increased costs meant operating profit margins would be slightly below those a year ago.Cranswick said underlying sales in the year to March 31st climbed 12% on strong growth in demand for pork, bacon and cooked meats.Pastry sales also carried on increasing strongly after the company successfully launched several product ranges.Robust demand for pork products in Far Eastern markets boosted export sales well ahead of the levels in the previous financial year.But Cranswick said record input prices seen during the year impacted operating margins."Despite some recovery as the year progressed, operating margins will, as expected, be slightly below those achieved in the previous financial year," Cranswick said in a trading update.PW