تاثير نانوذرات كيتوزان حاوي اسيد فوليك جيره بر شاخص هاي رشد در ماهي قزل آلاي رنگين كمان انگشت قد (Oncorhynchus mykiss)

The effect of chitosan nanoparticles coated with folic acid to feed on growth parameters in rainbow trout (Oncorhynchus mykiss) fingerlings

ﻫﺪف از اﻧﺠﺎم اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮرﺳﯽ ﺗﺎﺛﯿﺮ ﻧﺎﻧﻮذرات ﮐﯿﺘﻮزان ﺣﺎوي اﺳﯿﺪ ﻓﻮﻟﯿﮏ در ﺟﯿﺮه ﻏﺬاﯾﯽ ﻣﺎﻫﯽ ﻗﺰلآﻻي رﻧﮕﯿﻦﮐﻤﺎن اﻧﮕﺸﺖ ﻗﺪ ) (Oncorhynchus mykissﺑﺮ ﺷﺎﺧﺺﻫﺎي رﺷﺪ و ﺑﻘﺎ ﺑﻮد. ﺑﻪ اﯾﻦ ﻣﻨﻈﻮر ﻣﺎﻫﯿﺎن ﻗﺰل آﻻي رﻧﮕﯿﻦ ﮐﻤﺎن ﺑﺎ ﻣﯿﺎﻧﮕﯿﻦ وزن 2 ± 30 ﮔﺮم در ﭘﻨﺞ ﺗﯿﻤﺎر آزﻣﺎﯾﺸﯽ ﺷﺎﻫﺪ، 0/1، 0/25، 0/5 و 1 ﻣﯿﻠﯽﮔﺮم ﻧﺎﻧﻮذرات ﮐﯿﺘﻮزان-اﺳﯿﺪ ﻓﻮﻟﯿﮏ ﺑﺮ ﮐﯿﻠﻮﮔﺮم ﻏﺬا ﺗﻘﺴﯿﻢ ﺷﺪﻧﺪ. ﻫﺮ ﺗﯿﻤﺎر ﺣﺎوي 25 ﻗﻄﻌﻪ ﺑﭽﻪ ﻣﺎﻫﯽ، در 3 ﺗﮑﺮار و 15 ﻣﺨﺰن 500 ﻟﯿﺘﺮي در ﯾﮏ ﺳﯿﺴﺘﻢ ﭘﺮورش ﻣﺪار ﺑﺴﺘﻪ ﻃﺮاﺣﯽ ﺷﺪ. ﭘﺲ از ﺳﺎﺧﺖ ﺟﯿﺮه دﺳﺘﯽ و ﺳﺎزﮔﺎري ﻣﺎﻫﯿﺎن ﺑﺎ ﺷﺮاﯾﻂ ﺟﺪﯾﺪ؛ ﺑﻪ ﻣﺪت 8 ﻫﻔﺘﻪ ﻣﻮرد ﺗﻐﺬﯾﻪ آزﻣﺎﯾﺸﯽ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﭘﺲ از اﺗﻤﺎم دوره ﭘﮋوﻫﺶ ﺷﺎﺧﺺﻫﺎي رﺷﺪ و ﺑﻘﺎ ﻣﻮرد ارزﯾﺎﺑﯽ ﻗﺮار ﮔﺮﻓﺖ. ﺑﯿﺸﺘﺮﯾﻦ اﻓﺰاﯾﺶ وزن ﺑﺪن در ﺗﯿﻤﺎر 1 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﮐﯿﻠﻮﮔﺮم ﻏﺬا ﺑﻪ ﻣﯿﺰان 4/34 ± 69/23 ﮔﺮم ﺛﺒﺖ ﺷﺪ. ﺑﺎ اﻓﺰاﯾﺶ ﺳﻄﺢ ﻧﺎﻧﻮذرات ﮐﯿﺘﻮزان-اﺳﯿﺪ ﻓﻮﻟﯿﮏ در رژﯾﻢ ﻫﺎي ﻏﺬاﯾﯽ ﻓﺮﻣﻮﻟﻪ ﺷﺪه ﺿﺮﯾﺐ ﺗﺒﺪﯾﻞ ﻏﺬا ﺑﻪ ﻃﻮر ﺧﻄﯽ ﮐﺎﻫﺶ ﯾﺎﻓﺘﻪ ﮐﻪ در ﻣﺎﻫﯽﻫﺎي ﺗﻐﺬﯾﻪ ﺷﺪه ﺑﺎ 1 ﻣﯿﻠﯽﮔﺮم در ﮐﯿﻠﻮﮔﺮم رژﯾﻢ ﻏﺬاﯾﯽ ﻣﮑﻤﻞ ﻧﺎﻧﻮذرات ﮐﯿﺘﻮزان-اﺳﯿﺪ ﻓﻮﻟﯿﮏ ﺑﻪ ﮐﻤﺘﺮﯾﻦ ﻣﻘﺪار ﺑﻪ ﻣﯿﺰان 0/08 ± 1/29 رﺳﯿﺪ )0/05

The aim of this study was to investigate the effect of chitosan nanoparticles containing folic acid in the diet of rainbow trout, Oncorhynchus mykiss on growth and survival indices. For this purpose, rainbow trout with an average weight of 30 ± 2 g were divided into five experimental treatments: 0, 0.1, 0.25, 0.5 and 1 mg of chitosan/folic acid nanoparticles per kg of diet. Each treatment containing 25 fish in 3 repetitions in 15 tanks (500 liter) was designed into a closed-circuit breeding system. After making a manual diet and adapting the fish to the new conditions they were fed for 8 weeks. At the end of the experiment period, growth and survival indices were evaluated. The highest growth rate was recorded in the treatment of 1 mg/kg of chitosan/folic acid nanoparticles at the rate of 69.23 ± 4.34 g. With increasing Ch/FA nanoparticles levels in the formulated diets, the feed conversion ratio decreased linearly, which in fish fed with 1 mg/kg diet supplemented with chitosan / folic acid nanoparticles reached to 1.29 ± 0.08 (p<0.05). On the other hand, the survival rate was the same in all treatments, but at the end of the period, losses were clearly observed in the control. The results showed that increasing the level of chitosan/folic acid nanoparticles in formulated diets will increase the growth rate and have a positive effect on growth index.