ImmuCell Corporation is an animal health company. The Company is engaged in the development, acquisition, manufacture, and sale of products that improve the health and productivity of dairy and beef cattle. It operates in two business segments: Scours and Mastitis. The Scours segment is engaged in manufacturing and selling First Defense, a product used to prevent scours in newborn calves, which is regulated by the United States Department of Agriculture (USDA). The Mastitis segment is focused on developing and commercializing Re-Tain, a product to treat subclinical mastitis in lactating dairy cows. The First Defense product line provides bovine antibodies that newborn calves need but are unable to produce on their own immediately after birth. Its product line extension, Tri-Shield First Defense, is the first calf-level, passive antibody product providing Immediate Immunity against each of the three causes of calf scours (E. coli, coronavirus, and rotavirus).