EFFECTS OF VITAMIN-A-DEFICIENCY ON THE REPRODUCTIVE-SYSTEM OF MATURE WHITE LEGHORN HENS

Two groups of 100 white leghorn hens were fed rations either supplemen ted or deficient in vitamin A for 32 weeks. At the conclusion of the s tudy, vitamin A-supplemented hens laying normally were also compared w ith a group of vitamin A-supplemented hens in a state of low egg produ ction. Mean egg retinol equivalents (mug retinol/g egg yolk), egg prod uction, and hatchability in the vitamin A-deficient group were decreas ed significantly by 4, 20, and 28 weeks, respectively, after beginning treatment. The ovaries of vitamin A-deficient chickens had increased numbers of atretic follicles compared with the ovaries of vitamin A-su pplemented hens (20, 24, 28, and 32 weeks), and these atretic follicle s contained moderate to severe hemorrhage. Hemorrhage was located eith er uniformly throughout the follicle or more commonly between the deta ched granulosa cell layer and the theca interna. Hemorrhagic follicles were uncommon in both vitamin A-supplemented hens and low-production vitamin A-supplemented hens.