I have lost over 10% of my Cornish Cross chicks in just 2 weeks. All were alive on arrival. I started with 132 and am down 13-14 birds. They have plenty of fresh water (with some added vitamins), 12 hours on and 12 off of Purina Flockraiser. I monitor the temperature of the coop several times a day and open it up for fresh air if it's warm enough. They have plenty of open space to move around. I got them from Hoover Hatchery in Iowa. All of my layers from Meyer Hatchery are healthy, thriving and spoiled rotten. Anything I can do different for my meat birds? Thanks!