| Summary: | [EN] Both sexual maturation prior to fishing and escapes have a significant impact on the economic and environmental sustainability of the Atlantic salmon production (Salmo salar L.). The onset of sexual maturation during fattening decreases the growth because part of the energy obtained from the diet is used for gonadal development, in addition to also supposing a decrease in the quality of the meat. On the other hand, accidental escapes from fish farms can affect natural populations, influencing both ecologically and genetically. The production of sterile fish by the creation of triploid individuals has been considered an option for reproductive control and genetic containment in Atlantic salmon aquaculture. As in the case of other sterile artificially produced species, little is known about the nutritional requirements of triploid salmon. Identifying the optimal conditions to produce triploids is of great importance, as is the characterization of the physiological and morphological consequences of triplody in digestive physiology. Therefore, the objective of this work has been to study the effects produced by triploidy in Atlantic salmon (Salmo salar L.) on the biological activity of digestive enzymes. In addition, it has been evaluated whether the diet can compensate for possible digestive deficits produced by the triploidy. To this end, diploid and triploid fish were fed a standard and an experimental diet, in which 45 % of the fish meal was replaced by hydrolysed proteins. The study was conducted at the Kårvika Aquaculture Research Station (Tromsø, Norway), from the start of feeding until the phase of smoltification. Each month (except for the first months, which were twice), five fish were sacrificed per tank for the determination of the digestive activity of pepsin, trypsin, chymotrypsin, alkaline phosphatase, leucine aminopeptidase and total alkaline protease. In addition, the activity of pepsin was determined at gastric pH measured in the October and November sampling. The analysis showed that at the ...
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