13 research outputs found
Effect of replacing soybean meal with cottonseed meal on growth, hematology, antioxidant enzymes activity and expression for juvenile grass carp, Ctenopharyngodon idellus
Nutritional, physiological, and histological responses in Atlantic salmon, Salmo salar L. fed diets with genetically modified maize
The objective of this study was to evaluate whether standard
fish meal diets prepared with increasing levels of genetically
modified (GM; 150 and 300 g kg)1) maize (event MON810)
as a starch source, showed any nutritional or physiological
adverse effects on Atlantic salmon, Salmo salar L. postsmolt.
The diets with low or high inclusions ofGMmaize and its nearisogenic
parental line (nongenetically modified; nGM maize),
were balanced with Suprex maize (Reference) to obtain compositional
equivalency of diet starch, sugars and all other
nutrients. Total starch level in all diets was 160 g kg)1. After
82 days of feeding, fish growth was high in all groups, however
fish fed theGMmaize showed slight but significant lower feed
intake, which was followed by slight but significant lower
specific growth rate and final body weights, compared with fish
fed nGM maize, none of the groups varied significantly from
fish fed the Reference diet. There was no variation in feed
conversion ratios (FCR), protein and lipid efficiency ratios
(PER and LER), or protein- and lipid-productive values (PPV
and LPV) in this study. No significant effect of maize type was
detected on apparent digestibility coefficients (ADC) of dry
matter, protein or lipid. Hematological analysis and plasma
nutrients varied within normal ranges for Atlantic salmon in
all diet groups, except for somewhat elevated aspartate aminotransferase
(ASAT) values in all groups. Hepatosomatic
index (HSI) with values ranging from 1.37 to 1.60, was signi-
ficantly higher for the high GM maize group compared with
the high nGM maize group but not when compared with the
Reference diet group. Lowered spleen (SSI) and head-kidney
somatic indices (H-KSI) were registered when fed GM compared
withnGMmaize, the Reference treatment was however,
equal to both. Distal intestine somatic index (DISI) was significantly
higher for GM maize-fed fish compared with nGM
maize-fed fish, but not significantly different from the Reference
diet group. Histological evaluation of the mid- and distal
intestine, liver, spleen and head-kidney did not reveal any dietrelated
morphological changes. Maltase activities in the midand
distal intestinal tissue homogenates were affected by diet,
the fish fed high GM maize having higher activities compared
with highnGMmaize-fed fish. Leucine aminopeptidase (LAP)
and alkaline phosphatase (AP) activities were not affected by
diet. Sodium-dependent D-glucose uptake in brush border
membrane vesicles (BBMV) isolated from pyloric caeca of fish
fed highGMmaize was significantly higher than that found in
fish fed the analogous diet with high nGM maize.
Based on the present findings, the conclusions made are:
Atlantic salmon smolts fed GM maize (event MON810), its
near-isogenic parental line and suprex maize (Reference diet),
all resulted in high growth rates, ADC and feed utilization.
Health, when evaluated by means of mortality (low), normal
ranges of blood and plasma parameters, except somewhat
elevated ASAT values and minor variations in organ sizes,
were considered good in all diet groups. The changes in the
glucose transport mechanism and intestinal maltase enzyme
activity in the gastrointestinal tract warrant further studies