Effect of the gut microflora on the size and weight of organs of chicks fed diets of different protein content.

Germ-free (GF) and conventional (CV) chicks were reared for 14 d on diets containing 50 (LD), 200 (AD) and 400 (HD) g protein/kg. Food and water were provided ad libitum. The size and weight of the proventriculus, gizzard, duodenum, jejunum, ileum, caeca, colon, liver, pancreas, heart, spleen, adrenal glands and kidneys were measured, and liver composition was examined. The absolute and relative (weight/kg body-weight) weights of the intestine of CV chicks fed AD and HD diets were greater than those of GF chicks. The LD diet did not affect the absolute and relative weights of the duodenum and jejunum. The absolute weight, relative weight and fat content of the liver of GF chicks given LD diet were greater than those of their CV counterparts. The size and weight of some organs are affected by the diet (dietary protein content)-microflora-host interaction.