Food Technology Information Center

Technology of Forage and By-Products Preservation


Ensiling has become the most popular technology for preserving wet forage material for ruminants. Preservation by ensiling involves the application of several areas of knowledge, including microbiology, chemistry, food technology and animal nutrition, and our ability to influence the quality of the end product depends on our knowledge of these diverse areas. This makes the application of this technology a challenge. To preserve wet by-products and residues from the food industry, which usually create environmental problems, and to convert these wastes into useful feed materials presents an even greater challenge.

In spite of the importance of this technology in modern animal husbandry, ensiling is not yet a required course in most universities and, because of lack of knowledge, many mistakes are still made in silage making, even in the most modern farms. The border between success and failure, or between good and poor silage is very often narrow, and varied results can be obtained, even with the same raw material.

This booklet was prepared in order to provide the necessary information on the practical technology of forage and by-products preservation, especially in hot regions. Over the years, after each course I presented, I have felt the need to provide the students with the relevant information in a permanent form. Therefore, in this booklet I have attempted to gather together the most practical aspects of ensiling, including my personal experience, both in my laboratory in Israel and in the many countries in which I have carried out research.

The principal objective of this booklet is to present material based on a teaching course that is focused on the understanding of the various biological, physical and chemical processes needed to control fermentation, so as to achieve a high-quality final product.

I am indebted to many people, from whom I have learned many things. I therefore take this opportunity to express my great appreciation and warm gratitude to: Prof. Dr. E. Zimmer, Prof. Dr. H. Honig and Prof. Dr. G. Pahlow, and their technical support team in the Federal Research Center of Agriculture (FAL), Institute of Grassland and Forage Research in, Brunswick, Germany, where I spent two years and enjoyed a wonderful opportunity to experiment and study many aspects of forage preservation; to Prof. K. K. Bolsen and his team in the Department of Animal Science and Industry, Kansas State University, Manhattan, KS, USA, where I participated in studies on the effects of the diverse additives and of top losses in bunker silos; to Dr. R. da. C. Wanderley and Dr. A. G. da Silva and their team in the Brazilian Agricultural and Animal Husbandry Research Organization (EMBRAPA), Sao Carlos, SP, Brazil, for their invitation to study the preservation of tropical grasses, and the ensiling of industrial by-products and poultry manure; to Mr. D. Maughan of Peters & Brownes Group, and to the team in the Western Australian Agricultural, Dairy and Apiculture Industry Development Programme, where I had the opportunity for intensive study of problems of ensiling in Western Australian agro-climatic conditions; to Eng. A.H. Bosma and his team in the Harvesting and Handling Technology Department of the Institute of Agricultural Engineering (IMAG-DLO) in Wageningen, the Netherlands, where I focused my work on engineering aspects of forage preservation, especially on the dynamics of wilting; to Prof. Vivienne Gore Allen and her team in the Department of Plant and Soil Science at Texas Technological University, College of Agricultural Sciences and Natural Resources, Lubbock, TX, USA where I had the opportunity to teach graduate students and to focus on the forage problems in Texas.

In particular, I must thank Professor Allen for her encouragement in preparing this course and for offering me the opportunity to present it. I would also like to thank Mr. Philip Brown of the same Department, for his special help during the course and for summarizing the material, and to my colleague and partner Dr. Zwi Weinberg for his useful remarks.

This booklet is dedicated to my students and colleagues.

Gilad Ashbell