Agriculture Reference
In-Depth Information
Table 5.2.
Advantages of feeding studies with GM plant-derived feed/food with laboratory or target
animals.
Laboratory animals
Target animals
Internationally agreed study protocols
Representative for target animal species/categories
(extrapolation of data possible)
Small amounts of feed, higher number of
repetitions
Higher amounts of GM products are fed to animals
(recommendations for practical feeding, direct transfer of
results)
Lower costs for feed and equipment
All 'control' animals fed with comparators (isogenic,
commercial) are available for the market (no waste
animals)
Studies on the transfer of valuable and undesired
substances in food of animal origin (composition and
quality of the food)
Because of the normal biological ranges, the
dif erences between two groups should not
be overestimated. If two treatments are
signii cantly dif erent, that does not mean
that the dif erence is large enough to be of
any biological importance or any practical
signii cance. h erefore, one or more com-
mercial reference lines were later included in
such studies to help compare the data with
commercial lines. Some statistically sig-
nii cant dif erences between the GM plant
and the near-isogenic line may occur by
chance and may not be biologically relevant.
Reference lines may help to delineate the
range of values typical for the crop type
(ILSI, 2003; EFSA, 2011a). For experimental
design, the following parameters/criteria
should be stated clearly:
Animal species/category.
Number of animals; number of groups.
Termination of experiment.
Initial body weight.
Highest portion of GM feed should be
included or better: dose-response studies.
Clear characterization/analysis of all feed
used in the study.
Balanced diets, adjusted diets according
to the scientii c recommendations of the
National Research Council (NRC) or the
Society of Nutrition Physiology (GfE) for
animal species/categories.
Health and welfare; keeping of animals.
Feed intake, weight gain or animal yield.
Removal of animals; animal losses.
All studies should be conducted according to
internationally accepted protocols (OECD,
1998a,b; ILSI, 2003, 2007; EFSA, 2008,
2011a). Statistical analysis and interpre-
tation of results should be done according to
adequate publications and under con-
sideration of the EFSA's comments (2011c).
Usually, the OECD guideline tests (OECD
TG 407 and 408; OECD, 1998a,b) for
chemicals are used for the safety testing of
single substances including new products
resulting from genetic modii cation (e.g.
newly expressed proteins; EFSA, 2006,
2008). Generally, rodents (rats or mice) are
used over a period of 28 days/1 month for
single-dose or repeated-dose toxicity testing.
h e detailed testing strategy should be
selected on a case-by-case basis, based on
prior knowledge regarding the biology of the
products, so that relevant end points are
measured in the test (for more details see
OECD, 1998a,b; EFSA, 2006, 2008, 2011b;
FDA, 2007).
A 90-day rodent feeding study should be
carried out, as indicated by molecular,
compositional, phenotypic, agronomic or
other analysis (e.g. changes in metabolic
pathways). Such toxicity studies should only
be performed on a case-by-case basis to
provide additional information for the risk
