Agriculture Reference
In-Depth Information
Table 10.4.
Milk composition of the fi rst and second lactation of a long-term feeding study with dairy
cows (
n
= 18 per treatment; 25 months with Bt maize (MON810, 63% of roughage, 41% of concentrate
from maize)).
a
(From Spiekers
et al
., 2009.)
Lactation of experiment
First
P
level
Second
P
level
Parameter
Isogenic
Transgenic
Isogenic
Transgenic
Milk yield (kg/day)
Milk fat (%)
Milk protein (%)
Milk lactose (%)
Milk urea (mg/l)
Somatic cell count (1000/
ml)
23.9
3.95
3.62
4.83
164
23.7
4.03
3.71
4.82
181
0.566
0.015
<0.001
0.155
0.001
29.2
3.75
3.59
4.74
180
28.8
3.86
3.56
4.80
175
0.419
0.055
0.299
0.006
0.523
157
205
0.073
241
220
0.754
Note
:
a
No fragments of Cry1Ab DNA in blood, milk, faeces and urine of cows; traces of Cry1Ab protein were detected in
faeces, but not in blood, milk and urine (Guertler
et al
., 2009).
Table 10.5.
Selected parameters of milk composition, protein fractions and fatty acid
proportion in milk of dairy cows fed conventional or Bt 176 maize (12 cows per treatment;
70% of DM maize silage). (From Barriere
et al
., 2001.)
Parameter
Isogenic control
Transgenic maize, Bt 176
Milk yield (kg/day)
31.5
31.8
Milk fat (%)
3.69
3.68
Milk protein (%)
3.20
3.18
Total caseins (g/kg)
24.9
24.9
-Lactalbumin (g/kg)
1.12
1.16
ß-Lactoglobulin (g/kg)
3.86
3.90
Curd yield (%)
15.2
15.0
Fatty acids (% of total):
C
4
- C
12
14.3
15.2
Total C
14
13.5
14.0
Total C
16
41.1
41.0
C
18:0
8.8
8.5
C
18:1
16.5
15.9
C
18:2
2.1
2.1
Some authors (e.g. Aulrich
et al
., 2001;
Berger
et al
., 2003; Erickson
et al
., 2003)
have also reported that the inclusion of i rst-
generation GM feed in the diets of beef
cattle did not af ect body composition,
marbling score, fat depth, area of
Musculus
longissimus dorsi
or yield grade (Table 10.6;
see also Chapter 6; Table 6.3).
Erickson
et al
. (2003) fed high portions of
glyphosate-tolerant maize (GA21, NK603)
to feedlot steers in three studies and
measured some meat parameters. h ey did
not i nd any signii cant dif erence between
transgenic maize, its isogenic counterpart
and two commercial lines (Table 10.7).
Feeding studies with feed from GM plants
with input traits in small ruminants show
similar results to those described with
lactating cows and bulls/steers. Stanford
et
al
. (2003) fed transgenic Roundup Ready
(RR) canola meal to lambs (from 21.5 to 45
kg body weight) and compared it with the
parenteral line and two commercial lines.
h e inclusion level of canola meals in the
experimental diets was only 6.5%. Carcass
composition, chemical composition of
Musculus longissimus dorsi
and meat quality
parameters were not inl uenced signii cantly
by the canola sources.
Similar ruminant feeding studies with
pigs did not show any signii cant ef ects of
feeds from i rst-generation GM plants on
carcass composition and quality. Hyan
et al
.
(2004) compared two studies with RR maize
