Growth characteristics of skeletal muscle tissue in Oreochromis niloticus larvae fed on a lysine supplemented diet
Abstract:The effect of lysine amino acid supplementation on the growth characteristics and morphological pattern of skeletal muscle tissue in Nile tilapia Oreochromis niloticus larvae was evaluated. There were four treatments (T) with increasing levels of lysine supplement (T1 = 0·0%; T2 = 1·1%; T3 = 1·7%; T4 = 4·0%) and one treatment with a commercial diet (T5). In all treatments, morphological and histochemical muscle tissue analyses were similar. Two distinct layers were identified: a superficial red layer, more developed in the lateral line region, formed by fibres with intense to moderate NADH‐TR reaction and strong acid‐stable mATPase activity, and a deep white one, most of the muscle mass, formed by fibres with weak NADH‐TR reaction and strong alkali‐stable mATPase activity. There was an intermediate layer between these two layers with fibres exhibiting either weak acid‐stable or acid‐labile mATPase activity. Body mass increase was significantly higher in T5 than in the lysine treatments (T1–T4). There was no difference in number and diameters of muscle fibres between lysine treatments. In T5, muscle fibre diameter and number were higher. The frequency of red fibres with diameters ≤8 μm was higher in the lysine treatments, and with diameters between 16 and 24 μm, was higher in T5. Most white fibre diameters in T5 were significantly larger than 24 μm and in T1–T4 were between 8 and 16 μm. Cell proliferation was higher in the lysine treatments and muscle growth in T5 was mainly by fibre hypertrophy.
Document Type: Regular Paper
Affiliations: 1: Department of Cellular Biology, Institute of Biology, UNICAMP, Campinas, SP, 13 084 971, Brazil, 2: Department of Animal Improvement and Production, FMVZ, UNESP, Botucatu, SP, 18 618 000, Brazil and 3: Department of Biostatistics, Institute of Biosciences, UNESP, Botucatu, SP, 18 618 000, Brazil 4: Department of Morphology, Institute of Biosciences, UNESP, Botucatu and CAUNESP, SP, 18 618 000, Brazil,
Publication date: 2005-10-01