Growth, body proximate composition and selected blood parameters of rainbow trout Onchorhynchus mykiss fingerlings fed on a diet supplemented with nettle Urtica dioica and tarragon Artemisia dracunculus

Abstract

Diet supplemented with nettle Urtica dioica and tarragon Artemisia dracunculus leaf powder on fingerling rainbow trout Oncorhynchus mykiss was assessed. Fish of initial body weight 7.41 ± 0.16 g, were distributed in six groups, three replications, and were fed 8 weeks. 0 (control), 10 nettle (N1), 30 nettle (N3), 10 tarragon (T1), 30 tarragon (T3) and 10 nettle +10 tarragon g/kg (N1+T1) diet. The N3 improved FBW, WG, WG% and SGR significantly (p ≤ 0.05). N3 increased body protein, ash and decreased body fat significantly (p ≤ 0.05). The highest haematocrit was observed in T3 significantly (p ≤ 0.05). The highest WBC in T3, and RBC and Hb in N1+T1 were observed (p ≤ 0.05). N1 and N1+T1 showed the highest MCV (p ≤ 0.05). N1, T1 and N1+T1 showed the highest MCH (p ≤ 0.05). The highest MCHC was observed in T1 significantly (p ≤ 0.05). N3, T3 and N1+T1 demonstrated the highest albumin levels (p ≤ 0.05). The T1 increased serum lysozyme activity compared to control (p ≤ 0.05). The highest serum total immunoglobulin and total protein in N3 were observed (p ≤ 0.05). The results showed beneficial effects of N3, T3 and N1+T1 on growth performance, body proximate composition and blood parameters.

Nettle (Urtica dioica) Additive as a Growth Promoter and Immune Stimulator in Fish

“…Nettle, like other herbs, has been used in fish diets in two forms: powder and extract. Nettle powder is prepared from aerial parts [ 33 , 34 ], leaves [ 22 ], and stems [ 35 ] similar to other herbs. Collected nettle samples were washed with distilled water [ 24 ].…”

“…Collected nettle samples were washed with distilled water [ 24 ]. Then, the samples were dried in the shade at room temperature [ 22 , 36 ] and/or in the shade under ambient conditions under a flow of dry air [ 37 ]. The benefits of using powdered herbs like nettle include the fact that it is acceptable for fish, is widely available and cheap, and can easily be added to diets.…”

“…Furthermore, it is interesting to see how fish growth and health can be affected by extraction methods. According to the documented results, both nettle powder (ranging from 0.5% to 12%) [ 21 , 22 , 35 , 37 ] and extract with different methods (ranging from 0.01% to 3%) [ 23 , 33 , 40 ] in fish diets demonstrated positive effects on fish growth performance and health status [ 26 ]. This shows that both powder and extract of herbs could be effective and that extraction did not add any positive effects.…”

“…In addition, 1% nettle increased hematocrit (Ht%) compared to the control. Nettle, as a medicinal plant additive, has been evaluated in fish feeds and has improved growth performance, proximate body composition [ 22 ], immune system, and resistance against pathogens [ 23 , 24 ] and preserved fish fillet quality [ 25 ]. The literature has also briefly reviewed the effect of nettle on fish growth performance and the immune system [ 26 ].…”

Blood Performance: A New Formula for Fish Growth and Health

“…Table S3: the relationship between supplementation to fish diet with growth, haematological parameters, blood performance, and immune system in fish meal replacement studies. References: [ 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 , 136 , 137 ] are cited in supplementary materials.…”