Dietary and management procedures for development of consistent hemorrhagic symptoms in chicks.

Chicks hatched from S.C.W.L. pullets housed in laying cages and fed a diet without vitamin K were compared with chicks hatched from pullets fed a similar ration supplemented with vitamin K3 at 750 mcg./kg. of feed. Eggs were incubated after 4, 5 and 7 months vitamin K depletion. Chicks were fed a basal chick starter with no source of vitamin K or the basal supplemented with various levels of sulfaquinoxaline (SQ) (0.0125-0.050%) or with 750 mcg./kg. of vitamin K3. Blood clotting time was determined on chicks at the beginning and at weekly intervals during each experiment. Blood clotting time was significantly increased by a SQ feeding, but no hemorrhages developed in chicks hatched from hens fed the diet containing vitamin K. Day-old chicks hatched after 4 months vitamin K depletion showed elevated blood clotting times. There was no significant change in blood clotting time during the experiment for chicks fed the basal. Blood clotting time was significantly reduced in one week for chicks supplemented with vitamin K and increased for chicks fed 0.0375 or 0.050% SQ. These levels of SQ also resulted in 25 and 47.5% skin hemorrhages. Five months vitamin K depletion of breeder hens resulted in increased incidence of skin hemorrhages, but blood clotting times were similar to those at four months. Seven months vitamin K depletion of breeder hens resulted in increased blood clotting times as compared with 4 months and 100% incidence of hemorrhages in chicks fed rations containing 0.0375 or 0.050% SQ.