Studies on Coccidiosis and Vitamin A Nutrition of Broilers

SEVERAL early reports suggested a relationship between vitamin A adequacy of the diet and the chick’s resistance to coccidiosis. Murphy et al. (1938) found that the provision of adequate amounts of cod liver oil accelerated recovery from coccidiosis. Jungherr (1945) noted a relatively high association between the occurrence of vitamin A deficiency symptoms and cecal coccidiosis. Taylor and Russell (1946) also observed that when conditions were favorable for cecal coccidiosis, the severity of disease was enhanced in chickens receiving less than the minimum requirement of vitamin A. Davies (1952) noted that chickens suffering from natural infections of coccidiosis had lower storage of vitamin A per gram of liver than normal chickens fed the same diet. Schoop et al. (1954) reported that vitamin A deficiency reduces the resistance of chickens to coccidiosis. Erasmus et al. (1960) showed that, after infection with cultures containing both Eimeria tenella and Eimeria acervulina oocysts, chicks…