[The influence of various levels of carotene and protein in the diet on the index of invasion and digestive enzyme activity in chickens infected with Ascaridia galli].

Chickens 10 days old were infected with 500 eggs of Ascaridia galli. They were fed with diet containing 11% or 19% protein. Some of them were given beta-carotene in a dose equivalent to daily requirement of vitamin A, others were given double dose of beta-carotene. The intensity and extensity of invasion, the body weight, and activities of alpha-amylase, lipase and trypsin in pancreas and duodenal content were measured. Application of beta-carotene (especially in a double dose) caused the decrease in the invasion index and moderated the changes in the activity of digestive enzymes, occurring in the infected chickens.