The disappearance of dry matter, nitrogen and amino acids in the gastrointestinal tract from Calliandra leaves

Abstract

The total tract disappearance of dry matter (DM), nitrogen and amino acids in different Calliandra leaves harvested from Kenya and Zimbabwe were measured using the mobile bag technique. In the mobile bag measurements, disappearance was measured in the rumen in sacco, by pepsin–HCl hydrolysis in vitro and in the intestine. The hydrolysis in the pepsin–HCl solution was designed to mimic digestion in the abomasum. The total tract disappearance of DM, nitrogen, and amino acids were generally low. The highest total apparent DM, nitrogen and total amino acid disappearance obtained were 425 (g/kg), 458 (g/kg total nitrogen), and 593 (g/kg amino acid), respectively. There were differences between the leaves in the disappearance of DM, nitrogen and amino acids, and in the proportion of nutrients lost in the rumen, after pepsin–HCl hydrolysis and in the intestine. More DM, nitrogen, and amino acids in the leaves from Kenya disappeared in the intestine in comparison to the disappearance in leaves from Zimbabwe. The reasons for the differences between the nutritive values of the leaves is unclear but appears to be strongly influenced by the stage of growth and conditions in which the plants were grown.