Five isonitrogenous and isoenergetic diets were formulated to contain different levels of SCP. The control diet contained fishmeal and no SCP. SCP was included in experimental diets at 50g/kg, 100g/kg, 200g/kg and 250g/kg. The table below compares SCP against fishmeal
Table 1. Proximate and amino acid composition of fishmeal and SCP (g/kg DM).
| Empty Cell | Fishmeal | SCP |
|---|---|---|
| Dry matter | 892.0 | 940.0 |
| Crude Protein | 640.7 | 638.3 |
| Crude lipid | 58.7 | 62.9 |
| Ash | 140.8 | 92.7 |
| Calcium | 25.1 | 4.0 |
| Phosphorus | 16.3 | 15.8 |
| Crude Fibre | < 10.0 | < 10.0 |
| Gross Energy (MJ/kg) | 18.4 | 20.1 |
| Essential amino acids | ||
| Arginine | 38.3 | 46.9 |
| Histidine | 17.3 | 20.6 |
| Isoleucine | 28.4 | 38.5 |
| Leucine | 48.1 | 54.6 |
| Lysine | 51.6 | 45.3 |
| Methionine | 17.8 | 12.8 |
| Phenylalanine | 26.2 | 31.0 |
| Tyrosine | 20.9 | 33.6 |
| Threonine | 27.6 | 30.8 |
| Tryptophan | 13.9 | 15.8 |
| Valine | 32.9 | 56.4 |
| Nonessential amino acids | ||
| Alanine | 43.6 | 47.3 |
| Aspartic acid | 62.1 | 58.4 |
| Glutamic acid | 81.5 | 75.3 |
| Glycine | 50.4 | 36.9 |
| Serine | 25.1 | 20.4 |
Results indicated that final body weight of the shrimp increased with increasing levels of SCP up to 200g/kg. This diet also recorded the best feed efficiency when compared to other treatments.
Nitrogen (N) and phosphous (P) gain and retentions were improved in shrimp fed diets containing upto 200g/kg SCP. There was no significant difference in the whole-body chemical and amino acid composition of shrimp.
The digestibility of SCP by Pacific white shrimp was very high. Apparent protein digestibility of the SCP was greater than 0.90.
The innate immune response was higher in Pacific white shrimp fed diets with SCP than those fed the control diet. The expression levels of immune-relevant genes (lysozyme, Toll-like receptor and immune deficiency (IMD)) were up-regulated in the shrimp fed diet with 200g/kg of SCP.
Results of this work demonstrate that SCP from M. capsulatus can be efficiently used in the diet of P. vannamei up to 200 g/kg (two-thirds of fishmeal replacement) with significant beneficial effects on growth, feed and nutrient utilisation. SCP can be used in the diets of Pacific white shrimp upto 200g/kg without affecting growth and nutrient utilisation.
Details:
Nathan Felix, Kalidoss Manikandan, Arumugam Uma, Sadasivam J. Kaushik,
Evaluation of single cell protein on the growth performance, digestibility and immune gene expression of Pacific white shrimp, Penaeus vannamei, Animal Feed Science and Technology,
Volume 296, 2023, 115549,
https://doi.org/10.1016/j.anifeedsci.2022.115549.
