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641.
Seasonal changes of zinc, copper, and iron in gilthead sea bream (Sparus aurata) fed fortified diets
Emilio Carpeme Rossella Serra Maurizio Manera Gloria Isani 《Biological trace element research》1999,69(2):121-139
Four groups of gilthead sea bream (Sparus aurata) were fed diets with additional metal contents: a basal diet (diet A) contained Zn at 60.9 ± 1.9 mg/kg diet, Cu at 3.9 ±
0.9 mg/kg diet, and Fe at 138.3 ± 6.8 mg/kg diet; the other diets were supplemented with copper (20 mg/kg, diet B), iron (100
mg/kg, diet C), or zinc (300 mg/kg, diet D). Two consecutive year-classes (0+ and 1+ age fish) from the same parent stock were examined. Several fish tissues were analyzed for metal contents in five different
periods of each year in order to determine (1) the sensitivity of certain tissues as indicators of trace element metabolism
and (2) possible seasonal variations. Growth data were similar for gilthead sea bream fed the basal diet and the metal-fortified
diets. Mineral concentrations in tissues were found to be little affected by the dietary supplementation of trace elements,
suggesting an efficient homeostatic control of these three metal concentrations. Tissues involved in metal metabolism (e.g.,
liver, kidney, gills) presented greater variations between minimum and maximum values with respect to other tissues (e.g.,
brain, muscle, eye). Seasonal variations were observed during the 2 yr of this study and were especially evident for zinc
and copper concentrations in the liver. The overall pattern of metal variations showed a decreasing trend during the 2 yr.
Results from this study indicate that (1) trace element concentrations in fish tissues vary with age and life cycle and (2)
trace element requirements may vary in function of age and life cycle. 相似文献
642.
643.
A. R. Carlini H. O. Panarello M. E. I. Marquez G. A. Daneri G. E. Soave 《Polar Biology》2000,23(6):437-440
Deuterium-labeled water was used to measure changes in the proximate body composition during the lactation period and after
weaning in southern elephant seal pups at King George Island, South Shetland Islands, Antarctica. During the lactation period
(23.0 ± 1.4 days) pups gained a mean of 4.9 ± 0.5 kg/day (n=7). Of the total mass gain (112 ± 8 kg), 38% was water, 48% was fat, and 11% was protein. This represented an increase in
total body gross energy of 2437 ± 145 MJ. The proportion of body mass represented by fat was less than 2% at birth, increasing
to 35 ± 2% at weaning. We followed the pups during a mean period of 36 ± 3 days after weaning. During this period, pups had
a mean loss of 1.21 ± 0.10 kg/day (n=7) comprising 39% water, 48% fat, and 12% protein. The energy cost over this period was 952 ± 168 MJ, which represented,
on average, 39% of the total energy gained during the suckling period.
Accepted: 3 January 2000 相似文献
644.
E J Carlini B A McPheron C M Felland L A Hull 《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1991,99(3):375-377
1. Esterase activity in the tufted apple bud moth was measured spectrophotometrically by the hydrolysis of alpha-naphthyl acetate. 2. Resistant populations from both laboratory and field exhibited significantly greater esterase activity than did the respective susceptible populations. 3. The resistant laboratory population had significantly higher esterase activity than the resistant field population, suggesting that this field population contained a mixture of resistant and susceptible individuals. 相似文献