CONTENTS. 



Page. 



Introduction 7 



The fasting katabolism 8 



Purpose of the fasting katabolism 9 



The material katabolized 10 



Ash 10 



Fat 10 



Carbohydrates 10 



Protein 11 



Ratio of protein to total katabolism 11 



Influence of body fat 12 



Influence of surplus protein 13 



Relative constancy of energy katabolism 13 



The energy requirement for maintenance 16 



Replacement of nutrients 16 



Feed fat and body fat 16 



Carbohydrates and body fat 17 



Carbohydrates and feed fat 17 



Feed protein and body fat 17 



Fat or carbohydrates and protein 18 



Availability of energy. . „ 19 



Availability for cattle 20 



Availability for the horse — Zuntz and Hagemann's results 22 



Digestive work for crude fiber 23 



Work of mastication 23 



Computation of available energy 24 



Availability for the horse— Wolff's results 25 



Availability for carnivora 26 



Causes of increased metabolism 28 



Mechanical work 29 



Secretion 29 



Fermentation 29 



Digestive cleavages 30 



Intermediary metabolism 31 



Excretion 32 



The maintenance ration 33 



Relation of maintenance requirement to live weight 36 



Computation of relative body surface 38 



The maintenance rations of farm animals 39 



Cattle 39 



Sheep 48 



Swine 51 



The horse 55 



Zuntz and Hagemann's investigations 55 



Wolff's investigations 57 



Mtintz's experiments 62 



Grandeau and Le Clerc's results 62 



True maintenance and live- weight maintenance 6 



5 



