Louisiana Downs has canceled the opening card of its Quarter Horse meet Saturday because of freezing temperatures. The track was one of several in the region forced to alter racing plans because of a cold front. Delta Downs in Vinton, La., canceled the final eight races on its program Friday night due to the weather, while Sam Houston Race Park in Houston called off its entire Friday night card earlier in the day because of a frozen racing surface. \nLouisiana Downs had two stakes scheduled for Saturday and both will be brought back at a yet to be determined date, said Trent McIntosh, the track's director of racing operations. Temperatures in Bossier City, La., were in the 20's on Friday night, with the forecast looking much the same for Saturday. \nSam Houston officials anticipate being able to race on Saturday night, but have canceled morning training for Saturday.