FEED MIX

THE INTERNATIONAL JOLRNAL ON FEED. NUTRITION AND TECHNOLOGY

Latest developments in nutrition research, presented by Naheeda Khan _______________________6

The scientific study of food cues and appetite is in its infancy with many questions left open. Dr Jon Day gives us some answers. ________________________________10

The idea of using purine derivative excretion as a index of microbial synthesis is developed and tested by By Dr J Balcells and Dr J F Perez. ________________________________15

INDEX TO FEED Mix VOLUME 6,1998

A complete listing of articles published in last year's Feed Mix. ___________20

Optimising pig production relies on considering biological, nutritional and financial constraints to the farming system. Jaap van Milgen shows how mathematics can unravel these complex problems to ease the decision making process.__________________________22

Authors Afzal et al show how food restriction adversely affects the immune response and impairs the cellular defence mechanism of the respiratory system.______________________26

As meat production continues to grow across the world, the supply of materials for rendering will increase. Thus argues Tony Shepherd in favour of animal proteins as a regular renewable source of nutrients. ___ ____ _____________________30

During the dry season in the tropics, animal performance can suffer as a result of poor nutrition. Dr P I Rekwot gives advice on how to avoid the problem in bulls._____________34

lit its raw state, neem seed is too bitter to be accepted by poultry as a feed ingredient. Dr D Nagalakshmi and Dr S V Rama Rao explain how appropriate processing converts this important crop into a valuabl e protein source.________________________________________36

In a the first of a two-part series Dr Andrew Chesson and Dr H J Flint review the penetration of GMOs into the feed industry, and what this means from a safety perspective. _______________38

FEED MIX Contents

VOL. 7 NO. 3 , 1999


ANIMAL NUTRITION'S IMPACT ON THE ENVIRONMENT
Intensive livestock production puts a heavy load on THE environment. Norman Dunn sum-
manses the problems that go with the emission and excretion of unwanted products. 8

PHYTASE CUTS PHOSPHORUS LOSSES
David Cowan and Naheeda Khan define the role of phytase in the war against phosphorus 14
pollution.

BALANCING AMINO ACIDS TO DECREASE NITROGEN
POLLUTION
One of the best ways to reduce the emission of nitrogen is to minimise the input of protein 17
in the feed as is explained by Eddy Ketels.

AMMONIA EMISSION FROM PIG HOUSES AS AFFECT
ED BY DIETARY COMPOSITION
Andre Aarnink and Truong Canh investigated the possibilities of reducing ammonia emission 23
of pigs by altering the composition of the pig feed.

ENVIRONMENTAL AND ECONOMIC IMPACTS OF
NUTRIENT FLOWS IN DAIRY FORAGE SYSTEMS
A long term project in the USA is coming to an end and results in a dairy forage system 29
model. Dick Ziggers reviews.

SAFETY IMPLICATIONS OF GENETICALLY MODIFIED
ORGANISMS I
Harry Flint and Andrew Chesson explore possible undesirable effects of GMO's. 32

TRACE MINERALS AND SOURCES IN THE DAIRY
PRODUCTION CYCLE
Trace minerals are important ingredients in the feed. Bruce Johnson and Michael Socha dis- 36
cuss many of them with an emphasis on zinc.

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