Influence of Feeds from GM Plants on Composition/Quality of Food of Animal Origin - Animal Nutrition with Transgenic Plants - page 142

10.2.1 Recombinant DNA and newly
expressed proteins

et al ., 2012). It cannot be excluded that small
protein fragments (e.g. peptides) may pass
the intestinal epithelium.
Some authors want a labelling of food of
animal origin after consumption of GM feed
(e.g. Seralini et al ., 2011; Antoniou et al .,
2012). Such wishes cannot be scientii cally
justii ed because of the inconsistency of
detection of recombinant DNA and newly
expressed protein in animal tissues, milk
and eggs.

Recombinant DNA (see Chapter 9) is mainly
degraded during ensiling (Hupfer et al .,
1999; Aulrich et al ., 2004), feed processing
(Gawienowski et al ., 1999; Chiter et al .,
2000; Alexander et al ., 2002; Berger et al .,
2003) and in the digestive tract of animals
(Alexander et al ., 2004, 2007; Einspanier et
al ., 2004; Wiedemann et al ., 2006). It cannot
be ruled out that gene fragments enter the
intestinal epithelium and are absorbed by
the host organism. Low copy DNA (e.g.
recombinant DNA) has mainly not been
detected, while multi-copy DNA (endo-
genous DNA; e.g. Rubisco DNA) has been
detected in several body samples (Sanden et
al ., 2011). Up to now, many authors have
not found recombinant DNA fragments in
animal body samples, milk or eggs (see
Einspanier and Flachowsky, 2009, and
Chapter 9), but some authors (e.g. Mazza et
al ., 2005; Sharma et al ., 2006; Tudisco et al .,
2006, 2010; Chainark et al ., 2008; Ran et al .,
2009) have amplii ed traces of recombinant
DNA fragments in animal tissues or milk.
Similar studies have been done with
newly expressed proteins (see Chapter 9).
Such proteins are degraded during feed
processing/conservation and in the digestive
tract, as demonstrated in in vitro studies and
in digestion and feeding experiments (Lutz
et al ., 2005; Wiedemann et al ., 2006;
Calsamiglia et al ., 2007; Guertler et al ., 2008;
Scheideler et al ., 2008; Paul et al ., 2010;
Buzoianu, 2011; Gruber et al ., 2011; Walsh

10.2.2 Product composition and
quality

Many studies have been conducted to
compare the quality of livestock products
obtained from animals fed with diets
containing feed from i rst-generation GM
plants (with input traits) with those
obtained from their isogenic counterparts.
Some results are exemplarily demonstrated
in Tables 10.3-10.11.
Milk composition (e.g. fat, protein,
lactose) and milk quality were not inl uenced
after the inclusion of i rst-generation GM
feed in dairy cattle diets (Table 10.3).
Similar results have been reported from a
long-term study recently completed (Table
10.4). Authors found no signii cant inl uence
on milk composition during the 25-month
experimental period.
More detailed analysis of milk from cows
fed with high portions of isogenic or Bt
maize (Table 10.5) did not show any
signii cant dif erences.

Table 10.3. Infl uence of feeding maize silage and maize grain from isogenic
and Bt maize on feed intake, milk production and milk composition of dairy
cows (average of two experiments; six or eight cows per treatment; duration of
experiment, 63 days; maize portion in ration: Experiment 1: 41.8% of DM
maize silage; 34.1% of cracked maize; Experiment 2: 59.6% maize silage;
19.9% cracked maize). (From Donkin et al. , 2003.)
Parameter Control maize Bt maize

Dry matter intake (kg/day) 24.3 24.1

Milk yield (kg FCM/day) a 33.2 33.2

Milk fat (%) 3.60 3.67

Milk protein (%) 3.10 3.14

Milk lactose (%) 4.62 4.64

Note : a FCM = fat-corrected milk.