Oskar waiter

Oskar Johann Kellner (born May 13, 1851 in Tillowitz , Silesia , † September 22, 1911 in Karlsruhe ) was a German agricultural chemist and animal nutritionist.

Live and act

Oskar Kellner's grave at the Südfriedhof in Leipzig

Oskar Kellner attended the secondary school in Neisse . In 1870/71 he took part in the Franco-German War and finished his school years with the Abitur exam in 1871. Kellner studied natural sciences with a special focus on chemistry at the Universities of Breslau and Leipzig. While still a student, he published his first scientific work in 1874 on the chemical processes involved in the germination of the pea and received his doctorate in 1875 at the University of Leipzig with the thesis "About some chemical processes in the germination of pisum sativum". phil.

After completing his doctorate, Kellner became an assistant at the Animal Physiological Institute of the Agricultural Academy in Proskau, Silesia. It was here that a number of publications emerged that earned him a growing reputation as an agricultural chemist.

In 1876 Kellner came to Hohenheim near Stuttgart as an assistant to Emil von Wolff , who from 1852 to 1854 was the first director of Germany's first agricultural research station, which was set up in Möckern near Leipzig in 1852 . Kellner published, partly together with Wolff, 24 papers in the field of plant and animal chemistry. Using very well-designed experiments with horses, Kellner was able to show in nitrogen excretion in 1879/80 that nitrogen-free nutrients can be used for muscle work and that protein is only used as an energy source when carbohydrates are not available in sufficient quantities. In doing so, he refuted Justus von Liebig's opinion , who assumed that only protein was an energy source for muscle work. Kellner already stated in this context that the energy content of the nutrients is perhaps the best measure for the nutritional value, i.e. already 3 years before Max Rubner formulated his law of the isodynamic effect of nutrients.

Kellner's versatility in plant and animal physiological research with extensive experimental work and his lecture activities also in front of excellent committees resulted in a high level of awareness.

Waiter rice field at the Komaba campus of Tokyo University

In 1880, at the age of 29, Kellner received a call to the Imperial University of Tokyo as Professor of Agricultural Chemistry, which he followed in 1881. In addition to training students in the field of agricultural chemistry, waiter in Japan dealt with soil and fertilization problems, especially when growing rice, as well as research methods for animal feed, especially for silage. Attempts to develop and nourish silkworms led to the result that this organism produced fat from carbohydrates: a much-cited work by Kellner in Japan. His research on rice and silkworms was of practical relevance to Japanese industry.

Kellner married a Japanese woman in Japan. This marriage and his versatile, successful work earned him high recognition from the country.

In 1892 Kellner was called back to Germany. In 1893 he became director of the agricultural research station in Möckern, where he turned to the determination of the feed value in the well-equipped laboratory, which interested him since he was 20 years old. First he worked up the test results of his predecessor Gustav Kühn on nitrogen and carbon balances in cows. In 1897, Kellner built another, well-functioning respiratory system for cattle, trained an excellent staff and introduced energy-based feed value determination. The effect of the various pure nutrients - starch, cellulose, sugar, protein and fat - on fat formation was examined. The idea of ​​comparing nutrients and feed in terms of value on the basis of the effect in the animal was the birth of the concept of net energy.

The experiments with pure nutrients were followed by experiments with feed from different groups. To assess the value of the wide range of feed on a net energy basis, he introduced the concept of value and the raw fiber deduction as correction variables. For the feeding of farm animals, he used the starch value , which expresses the energetic feed value of the feed in relation to that of the starch , for a better understanding for the practical farmers . The apparently material comparison was made strictly on an energetic basis.

Kellner has regularly reported on the results of his respiration experiments in the journal “Landwirtschaftliche Versuchsstätten”. He made a summarizing evaluation of his extensive experiments and experiences in his work “The Nutrition of Agricultural Farm Animals” (640 pages), which appeared in 6 editions from 1905 to 1912 and in four further editions until 1924 - initiated by G. Fingerling. Kellner supplemented this large textbook with an easy-to-read book “Grundzüge der Fütterungslehre”, which was published four times from 1907 to 1911. Eminent scholars kept this book up to date and published 16 new editions by 1984.

In the last few years of his life, Kellner's health was undermined, but his love of work was undiminished. In addition to introducing the theory of strength values ​​in the feeding of cattle, Kellner encouraged the various experimental stations to work together to conduct feeding experiments with dairy cows, horses and pigs.

Kellner's motto was: "Anything goes, you just have to want it!" He asked a lot of himself and of his co-workers. Waiter valued good work and was the man to work with. The high work ethic in the Möckern station was still evident decades after Kellner's death.

honors and awards

Kellner already received great recognition and numerous honors during his lifetime. For many years he was President of the Association of Agricultural Research Stations. Kellner received the title of Privy Councilor of Saxony, Professor of the University of Tokyo, a medical Dr. hc from the University of Wroclaw and he was also awarded the Liebig Medal in gold. Kellner was an honorary member of many societies at home and abroad, editor of “Biedermann's Zentralblatt für Agrikulturchemie” and “Die Landwirtschaftliche Versuchsstation”.

Major works

• The diet of the farm animals. Paul Parey Publishing House, Berlin; 1. Ed. 1905; 10th edition 1924.
• Basics of feeding theory. Paul Parey Publishing House, Berlin; 1st edition 1907; 4th edition 1911.

The starch value , the unit as a measure of the net energy content of feed in cattle, was used directly or in a converted form throughout Europe. In just a few years it had replaced feeding on the basis of digestible nutrients. Time and again, scientists found convincingly the superiority of the “net energy” measure over the “convertible energy” and over other measures.

Outlook and fruits of his labor

In 1953 the " Oskar-Kellner-Institute for Animal Nutrition" was founded in Möckern in part of the building of the experimental station in honor of Kellner , as an institute of the Academy of Agricultural Sciences. From 1954 to 1960 a new building of the "Oskar-Kellner-Institute for Animal Nutrition" consisting of 4 research buildings was built in Rostock. The director was academician Kurt Nehring . For the further development of the energetic feed evaluation in the sense of Oskar Kellner, 12 respiratory devices for farm animals and numerous for laboratory animals were available. In a work phase of almost four decades, the energetic feed value of various feeds was determined and the energy requirements of farm animals at different levels of performance were determined. The test results were summarized and a feed evaluation system was developed, which was to be named "Rostock feed evaluation system", but ultimately had to be published as the "GDR feed evaluation system". There were seven editions under this title until 1988. The benchmark for the energetic feed value and the energy requirement of the animals is the “net energy fat”. In 2003 and 2004, the publication took place under the originally intended title “Rostock feed evaluation system” in English and German, with “net energy retention” as the energy standard. Oskar Kellner's basic idea of ​​using net energy as a benchmark lives on in these titles.

literature

• K. Breirem: Oscar waiter. The Journal of Nutrition Vol. 47, 1952, pp. 3-10.
• Th. Gerber: Personalities from agriculture and forestry, horticulture and veterinary medicine -Bibliographisches Lexikon- Vol. 1: A – L. NORA Verlagsgemeinschaft Dyck & Westerheide, 2nd extended edition 2005, p. 352.
• R. Schiemann: On the 75th anniversary of Oskar Kellner's death (commemorative lecture). Arch. Animal Nutrition. 37: 906-912 (1987).
• Werner Wöhlbier:  Waiter, Oskar. In: New German Biography (NDB). Volume 11, Duncker & Humblot, Berlin 1977, ISBN 3-428-00192-3 , p. 478 f. ( Digitized version ).

Web links

• Literature by and about Oskar Kellner in the catalog of the German National Library