New developments and future perspectives in research on rumen function

European Commission Directorate-General For The Information Society And Media Directorate-General For Agriculture And Rural Development

Description

Agricultural and fisheries research
Animal production

Sujets

• Animal nutrition
• Animal Science (journal)
• Cattle
• Proceedings

Informations

• Publié par: EUROPEAN-COMMISSION-DIRECTORATE-GENERAL-FOR-THE-INFORMATION-SOCIETY-AND-MEDIA-DI
• Nombre de lectures: 27
• Langue: English
• Poids de l'ouvrage: 4 Mo

Extrait

Commission of the European Communities
AGRICULTURE
New developments and future perspectives
in research on rumen function
Report
EUR 10054 EN Commission of the European Communities
AGRICULTURE
New developments and future perspectives
in research on rumen function
Edited by
A. Neimann-Sørensen
A seminar in the EC programme of
coordination of agricultural research, organized by the
National Institute of Animal Science
Forsøgsanlæg Foulum, Denmark
25 to 27 June 1985
Sponsored by the
Commission of the European Communities
Directorate-General for Agriculture
Coordination of Agricultural Research
1986 EUR 10054 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Information Market and Innovation
Bâtiment Jean Monnet
LUXEMBOURG
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting on behalf of the
Commission is responsible for the use which might be made of the following information
Cataloguing date can be found at the end of this publication
Luxembourg, Office for Official Publications of the European Communities, 1986
ISBN 92-825-3467-7
Catalogue number:
© ECSC-EEC-EAEC, Brussels · Luxembourg, 1986
Printed in Luxembourg CONTENTS
Page
Background and objective v
Present and future feed resources for ruminants,
G. Alderman 1
Rumen fermentation and gastro-intestinal absorption
Rumenn andl absorption:
Carbohydrates, 21
J. D. Sutton
Rumen metabolism and gastro-intestinal absorption of
protein,
T. Hvelplund 39
Effect of fat on rumen fermentation and gastrointes­
tinal absorption, 55
Y. van der Honing and S. Tamminga
Magnesium, potassium and sodium: Interactions and
antagonisms,
H. Martens and G. Gabel 69
Physical structure of feeds for dairy cows,
8
P. Nørgaard
Modelling of rumen function,
D. E. Beever, J. France, M. K. Theodorou 10
Feed intake
Regulation of food intake on ruminants, ...
M. Journet
Prediction of feed intake,
V. Friis Kristensen, K. Lønne Ingvartsen 157
Modification and control of the ruminant digestive pro­
cesses
Treatment of feeds in relation to rumen function,
183
F. Sundstøl
New developments and future perspectives in research
on rumen function: Additives,
P. Thivend, J. P. Jouany 199
Future perspectives for the protection of nutrients
from fermentation in the rumen,
E. R. Ørskov 217
The bearing of feeding methods on digestion and
performance of dairy cows, ??
K. Rohr and D. Schlünsen
Microbial interactions, manipulation and genetic
engineering,
C. Stewart, Jaqueline Gilmour and M. L. McConville 243
— Ill — Page
Pathological aspects of rumen fermentation,
A. Th. van't Klooster 259
Summary of the final discussion,
G. Alderman, K. Rohr and S. Tamminga 277
Appendix. List of participants 281
IV — BACKGROUND AND OBJECTIVE
In the European Communities (EC) 37% of agricultural production is
derived from ruminants, and 63% of all farm units are involved in
production systems which depend on cattle, sheep or goats. Ruminants-based n is relatively more important in the less favoured areas of the
Community and is also the basis for utilization of both lands and feed
resources which cannot be exploited in other ways. Increasing efficiency in
the functioning of ruminant animals mil lead eventually to the provision
of a wide range of foods to the consumer at lower real costs.
In addition to these social, structural and economic considerations,
the potential of current and future technical developments in the
modification of both the feed and the animal offers real propects of
significantly improving efficiency and hence agricultural competitiveness
and incomes.
It was the object of the workshop to present and discuss the latest
developments and future propects in rumen funtion and ruminant nutrition,
to evaluate their significance for evaluation of feeds for ruminants, and
from this background to identify future research priorities.
— V — PRESENT AND FUTURE FEED RESOURCES FOR RUMINANTS
G. Alderman
University of Reading, Department of Agriculture and Horticulture
Earley Gate, Reading, RG6 2AT, United Kingdom
ABSTRACT
The range of feed resources used in ruminant feeding in EEC countries
has changed considerably over the last decade, as a result of powerful
economic and political forces. These are identified as the high price of
fossil fuel, the EEC Common Agricultural Policy as it affects the prices
of cereals and the subsidisation of vegetable protein sources, such as
rape, peas, beans, lupins and dried forages. The importation of soya bean
meal, maize gluten feed and manioc almost free of import duty is also a
major factor affecting the utilisation of cereals in ruminant feeding
particularly. There is also an increased awareness of the pollution of the
environment from nitrogenous fertiliser and existing methods of disposing
of wastes and byproducts from the human food industries. There have been
consequential effects on the amount and form of wastes and byproducts made
available for animal feeding. The drying of many byproducts has become
uneconomic, and they are now available only over a restricted radius from
the plant of origin, because of transport costs. High technology processes
for the production of single cell proteins have also been affected, as have
attempts to produce protected fats and proteins. A review of the major
feed resources has shown areas where there is still a need for research to
improve the utilisation of plant proteins, particularly in grass silage.
Emphasis is also placed on the need for modern and comprehensive methods of
feed analysis to be used when evaluating byproducts for ruminant feeding.
INTRODUCTION
The range of feed resources used in ruminant feeding has expanded
greatly during the last decade, and important changes in the selection of
feeds utilised have been brought about by several important economic and
political pressures. The pressures will continue to affect this sector in
the future, so some discussion of their effects is essential.
(1) The rise in the price of oil, as a result of the oil crisis of
1970s, has seriously affected the economics of all drying and heat
treatment processes for animal feeds and byproducts. Thus high temperature
drying of grass and lucerne now has to be subsidised by the EEC as an
important source of protein for animals. The drying of high moisture
byproducts from the food industry has become uneconomic in competition with
other feeds for animals. As a consequence, food manufacturers have
resorted to disposing of some byproducts in their fresh, high moisture
state. Brewers grains, pressed sugar beet pulp and brewery liquors are
examples. The high cost of fuel has also elevated transport costs, so that such byproducts are only available on a localised basis. Storage requires
either ensiling, with consequent changes to chemical composition and
nutritive value, or the addition of a preservative to prevent microbial
decomposition. High transport costs also reduce the distance that low
value byproducts such as cereal straw can be transported from areas of
surplus to areas of deficiency.
(2) The continuous rise over the last decade in the price of cereals
as determined by the EEC, has markedly influenced the proportion of
cereals included in compound feeds for ruminants and the use of cereals on
livestock farms. The importation of products such as manioc and maize
gluten feed relatively free of import duty has increased markedly, thus
adding to the cereal surplus in the EEC. It seems that serious attempts
will be made to reverse this situation in the next decade, so that greater
and economic use of cereals in the ruminant sector may return.
(3) In an effort to increase the self sufficiency of the EEC
countries for vegetable protein feeds, the EEC subsidises the growing of
oil seed rape, peas, beans and lupins. The expansion of oil seed rape
acreage has been striking, so that it now comes second only to soya bean
meal in its inclusion in compound feeds for ruminants, where its anti-
nutritional factors are of less importance than with pigs and poultry.
Peas and lupins also contain anti-nutritional factors, so that their use is
often constrained on this account.
(4) There is a growing awareness of pollution of the environment by
the disposal of effluents and byproducts. Costs of disposal have greatly
increased and legislation has been introduced in many countries control­
ling the disposal of polluting wastes. Thus liquid wastes such as brewery
effluents, starch from wheat gluten plants, and fermentation wastes from
biotechnology plants are being offered as feed for animals.
It is not intended to make a comprehensive review of the wide variety
of feed resources available for ruminant feeding, but rather to deal with
them in broad groups. There are however, aspects of this subject which
require consideration before that is attempted.
CHEMICAL COMPOSITION AXD NUTRITIVE VALUE
Whilst recognising