Lead-induced egg production decrease in Leghorn and Japanese quail hens.

A study was conducted to compare the response of chicken hens and Japanese quail hens to various levels of dietary lead as plumbus acetate. Egg production was decreased significantly in quail receiving 1 mg lead/kg of diet from day of hatch, and 10 mg lead/kg diet was required to suppress egg production when the metal was given to the quail hens after they had reached sexual maturity. In chicken hens given lead after they had attained approximately 80% hen-day production, a comparable decline in egg production was seen in hens consuming at least 200 mg lead/kg of diet. Total plasma calcium in quail hens was reduced significantly by 10 mg lead/kg of diet, but total plasma calcium in chicken hens was not reduced with levels of less than 200 mg lead/kg of diet. There was no correlation between blood calcium level and decreased egg production in chicken hens consuming dietary lead at levels less than 200 mg/kg diet, suggesting that lead influences egg production in birds through mechanisms that may not be dependent entirely upon calcium metabolism. Removal of lead from the diets of quail was associated with significant increases in egg production and total plasma calcium, but removal of lead from the diets of chicken hens did not cause any increase in total plasma calcium or increase egg production in treated hens. However, hens consuming the highest level of dietary lead (400 mg/kg) did increase significantly their rate of egg production, but this was attributed to recovery from a lead-induced molt.(ABSTRACT TRUNCATED AT 250 WORDS)