[The vitamin B 6 requirements of the laying hen for reproduction]

A total of 1125 hens were used in 3 feeding and 20 hatching trials. The trials were performed to investigate the influence of different vitamin B6 levels on the reproduction characteristics of the hens (fertilization of eggs, hatchability of the chicks, development of progeny). The vitamin B6 requirements of the hens were fairly low for maintaining normal fertilization and hatching rates (approximately 1.5-2 mg per kg of feed). Chicks reared on low vitamin B6 diets (0-12 days) showed definitely improved rearing characteristics (Food consumption, liveweight gains, losses) if the diet of the hens had been supplemented with graded amounts of vitamin B6. These findings were, in the first instance, due to an increased rate of vitamin B6 deposition in the liver and in the yolk sac of the newly hatched chicks (vitamin B6 reserves), apart from the fact that the overall vitamin B6 content of the egg remained largely unchanged. Variations in the vitamin B6 reserves, on the other hand, did not exert any influence on the development of progeny if the chicks received adequate amounts of vitamin B6.