Relation of Milk,Cholesterol and Estrogens to Cholic Acid Formation in Chicks.

Abstract

Liquid milk products in the diet of the chick are known to exert a preventive effect on the development of gizzard erosions caused by either a dietary deficiency or the presence of cincophen in the diet. 1 , 2 This preventive action of milk products is evidently related in both cases to an enhanced secretion of cholic acid. 2 An earlier report linked the gizzard erosions with a deficient formation of bile in the chick and especially of cholic acid in the bile. 3

Further studies have been made of the action of milk in promoting cholic acid formation in the chick. In general, the methods employed were the same as previously described. 2 , 3 Two types of diets were used, a complete practical diet containing 1% of cincophen and a deficient basal diet. 2 , 3

Attempts were also made to concentrate the anti-erosion and cholic acid-producing activity from whey by a procedure essentially similar to those used for the extraction of estrogenic substances from urine. 4 The extract obtained yielded distinct color tests for estrogens. 4 , 5 Presence of such substances in milk and whey has been reported. 6 We have, consequently, investigated known pure estrogenic compounds, since the presence of estrogens in milk and their general structural relation to the bile acids are particularly suggestive of a possible role in bile acid formation in the chick.

The results given in Table I confirm an earlier report 2 that milk products given in place of drinking water lead to an increased level of cholic acid in the gallbladder bile of the chick. In addition, it is shown that liquid buttermilk, whey and protein-free milk all exhibit an activity similar to that of skim-milk. The protein-free milk was made by isoelectric precipitation of casein, filtering, coagulation of remaining proteins by heating, filtering again and neutralizing.