Methods are described for the collection of abomasal secretion samples from calves and for the examination of the juice for proteolytic and rennin activity.
The effect of the rennin and pepsin concentration of the secretion was studied during two different methods of feeding milk viz. nipple feeding and drinking from the open bucket. It was found that both ways of feeding caused an increase in the rennin and pepsin concentration of the juice but that the effect of nipple feeding was greater.
The administration of carbamylcholine stimulated the abomasal secretion rate and also caused an increase in the rennin and pepsin content of the juice.
The injection of atropine, on the other hand, inhibited these functions.
It was also found that during a period of seven weeks the rennin concentration as well as the pH of the abomasal secretion of one calf fell steadily with increasing age.
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