Studies on energy metabolism, especially heat increment of feed stuffs for fowls

I. The heat increment in the process of triturating of diet in the gizzard and passing of indigestible matters through the alimentary tract

Abstract

It is known that the heat increment of feed stuffs for mammals is influenced by many factors. In the case of fowls, however, we have only a few pieces of information about this problem. In this study two experiments were carried out to clearify the heat increment in the mechanical digestive process of diets for fowls.
The diet used in the experiment on the trituration of diets in the gizzard and the heat increment was composed of 90% of corn, 6.7% of fish meal, and 3.3% of vitamin-mineral mixture. The grains of corn were powdered into granules smaller than 0.5mm for Diet 1 and broken into a few pieces for Diet 2. For Diet 3, they were left intact.
In the experiment on the passing of indigestible matters through the alimentary tract and the heat increment, washed blow sand and polyethylene powder, the granules of which were smaller than 0.5mm, were contained in the basal ration at the rate ranging from 0% to 40% respectively. Those indigestible matters were given so that the amount of the basal contained each diet was made equal.
Those diets were fed to broiler cockerels which weighed about 1kg and the energy metabolism was investigated.
The results obtained are summarised as follows:
1) The amount of the diet remaining in the crops and the gizzards of the cockerels fed with Diet 1, 2, and 3 became approximately the same 8 hours after feeding in spite of the differences of the diets fed.
2) No difference was observed among the cockerels fed with each diet in heat production continuously measured for 8 hours after feeding. The contents of metabolizable energy of each diet were also almost the same.
3) When indigestible matters were given at the rate ranging from 0% to 49.9g per kg0.75 of body weight, no significant difference was statistically observed in the heat production and heats for metabolizable energy ingested.
4) The value of heat increment per 1g of the indigestible matters was only 0.6 kcal, even in such a case as 49.9g of indigestible matters per kg0.75 of body weight were fed.