Open AccessEvaluation of dietary histidine supplementation on meagre, Argyrosomus regius , juvenile growth, haematological profile, stress and muscle cellularity
Author(s) -
Saavedra Margarida,
Pereira Teresa G.,
Ribeiro Laura,
Barata Marisa,
CandeiasMendes Ana,
Conceição Luis E. C.,
PousãoFerreira Pedro
Publication year - 2020
Publication title -
aquaculture nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 79
eISSN - 1365-2095
pISSN - 1353-5773
DOI - 10.1111/anu.13078
Subject(s) - biology , muscle hypertrophy , juvenile , antioxidant , zoology , histidine , limiting , endocrinology , medicine , biochemistry , amino acid , ecology , mechanical engineering , engineering
Histidine plays an important role in haemoglobin synthesis, antioxidant defence system and stress resistance, and it is thought to be a limiting amino acid in most meagre diets. In this study, two different diets, a control and a diet supplemented with 3% histidine, were tested in 60‐day‐old meagre (initial weight—6.2 g) for 82 days. Survival varied between 92% and 94%, and neither SGR nor whole fish composition seemed to be affected by the diet. When fish were submitted to a stress test (outside water for 30 s), it was observed that the levels of glucose and lactate significantly increased in both treatments. The concentration of cortisol increased after the stress test only in the His 30 g/kg group. Muscle cellularity was affected by the diets, where the control group showed a higher mean fibre area and lower fibre density. These results, associated with a lower frequency of smaller fibres, suggest a decrease in fibre recruitment and a higher fibre hypertrophy. In conclusion, the supplementation of diets with 3% led to a more pronounced response to the stress test in terms of cortisol levels and increased muscle fibre recruitment, decreasing muscle fibre hypertrophy contribution to muscle growth.