May 13, 1851 Born in Tillowitz/Silesia

1871-1875 Studies of Natural Sciences at the Universities of Breslau and Leipzig

1874 First publication ‘Über die chemischen Vorgänge beim Keimen von Erbsen’ (On the chemical processes during germination of pea)

1875/1876 Doctorate (Dr. phil.) at University of Leipzig. Kellner became assistant scientist at the Institute of Animal Physiology of the Agricultural Academy in Proskau and University of Hohenheim

1879/1880 Experimental proof that N-free nutrients can be used for muscle work. Three years prior to Rubner’s law on the isodynamic effect of nutrients, Kellner disproved Justus von Liebig’s hypothesis that only protein is an energy source for muscles.

1880 Appointment at the Imperial University of Tokyo, Japan, as a Professor of Agricultural Chemistry. Kellner performed experiments on development and nutrition of silk caterpillars arriving at the most important discovery that the organism can generate fat from carbohydrates.

1892 Appointment as director of the Agricultural Research Station in Möckern near Leipzig.

1897 Construction of a respiratory apparatus for cows. Determination of body fat storage from pure macronutrients and some feedstuffs. Following the comparison of nutrients and feedstuffs on the basis of their effects in animals, Kellner invented the concept of ‘net energy’. He further developed the ‘Stärkewertlehre’ which implies that the energetic value of feedstuffs is compared to that of pure starch and is termed ‘starch value’.

1905 and 1907 Publication of two books: ‘Die Ernährung der landwirtschaftlichen Nutztiere’ (Nutrition of Farm Animals); ‚Grundzüge der Fütterungslehre’ (Basics of Feeding). September 22,

1911 Kellner died during a conference of the German Agricultural Research Stations in Karlsruhe.