ﺗﺎﺛﯿﺮ دو ﺳﻄﺢ ﭼﺮﺑﯽ ﺟﯿﺮه ﺑﺮ ﺗﺮﮐﯿﺐ اﺳﯿﺪﻫﺎي ﭼﺮب ﻣﺎﻫﯽ ﻗﺰل آﻻي رﻧﮕﯿﻦ ﮐﻤﺎن (Oncorynchus Mykiss )

Effects of dietary fat levels on fatty acid composition of rainbow trout (Oncorynchus mykiss), during starvation and refeeding

در اﯾﻦ ﺗﺤﻘﯿﻖ اﺛﺮدوره ﻫﺎي ﮔﺮﺳﻨﮕﯽ و ﻏﺬادﻫﯽ ﻣﺠﺪد ﺑﺮ ﭘﺮوﻓﯿﻞ اﺳﯿﺪ ﭼﺮب ﻋﻀﻠﻪ ﻣﺎﻫﯽ ﻗﺰل آﻻي رﻧﮕﯿﻦ ﮐﻤﺎن ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. ﺗﻌﺪاد 240 ﻋﺪد ﺑﭽﻪ ﻣﺎﻫﯽ ﻗﺰلآﻻي رﻧﮕﯿﻦﮐﻤﺎن ﺑﺎ ﻣﯿﺎﻧﮕﯿﻦ وزن 14 ﮔﺮم ﺑﻄﻮر ﺗﺼﺎدﻓﯽ در 12 ﺗﺎﻧﮏ 150 ﻟﯿﺘﺮي ﺗﻮزﯾﻊ ﺷﺪﻧﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ 4 ﺗﯿﻤﺎر و 3 ﺗﮑﺮار وﺟﻮد داﺷﺖ ﮐﻪ ﺑﺎ دو ﺟﯿﺮه ي ﻣﺘﻔﺎوت ﭼﺮﺑﯽ ﻣﻮرد آزﻣﻮن ﻗﺮار ﮔﺮﻓﺘﻨﺪ . ﺗﯿﻤﺎر 1 ﻣﺎﻫﯽ ﻫﺎي ﺗﻐﺬﯾﻪ ﺷﺪه ﺑﺎ ﺟﯿﺮه ي 10% ﭼﺮﺑﯽ ﺑﺎ دوره ي دو ﻫﻔﺘﻪ ﮔﺮﺳﻨﮕﯽ ، ﺗﯿﻤﺎر 2 ﻣﺎﻫﯽ ﻫﺎي ﺗﻐﺬﯾﻪ ﺷﺪه ﺑﺎ ﺟﯿﺮه ي 20% ﭼﺮﺑﯽ ﺑﺎ دوره ي دو ﻫﻔﺘﻪ ﮔﺮﺳﻨﮕﯽ . ﺗﯿﻤﺎر 3 ﻣﺎﻫﯽ ﻫﺎي ﺗﻐﺬﯾﻪ ﺷﺪه ﺑﺎ ﺟﯿﺮه ي 10% ﭼﺮﺑﯽ ﺑﺪون ﮔﺮﺳﻨﮕﯽ و ﺗﯿﻤﺎر 4 ﻣﺎﻫﯽ ﻫﺎي ﺗﻐﺬﯾﻪ ﺷﺪه ﺑﺎ ﺟﯿﺮه ي 20 % ﭼﺮﺑﯽ ﺑﺪون دوره ي ﮔﺮﺳﻨﮕﯽ. ﺑﻌﺪ از دوره ﻫﺎي ﻣﺨﺘﻠﻒ ﺗﻐﺬﯾﻪ اي ﺗﺮﮐﯿﺐ اﺳﯿﺪ ﭼﺮب ﺑﺎﻓﺖ ﺑﺪن ﺗﻮﺳﻂ دﺳﺘﮕﺎه GCﺳﻨﺠﺶ ﺷﺪ . ﻣﻄﺎﺑﻖ ﻧﺘﺎﯾﺞ ﺑﺪﺳﺖ آﻣﺪه ﻣﺠﻤﻮع اﺳﯿﺪ ﻫﺎي ﭼﺮب ﺗﮏ ﻏﯿﺮ اﺷﺒﺎع (MUFA) ﺑﻌﺪ از دوره ي ﮔﺮﺳﻨﮕﯽ ﻧﺴﺒﺖ ﺑﻪ ﺗﯿﻤﺎر ﺗﻐﺬﯾﻪ ﺷﺪه اﻓﺰاﯾﺶ ﯾﺎﻓﺖ و در ﭘﺎﯾﺎن دوره ﻣﯿﺰان آن ﮐﺎﻫﺶ ﯾﺎﻓﺖ . در ﻣﻘﺎﺑﻞ ﻣﯿﺰان اﺳﯿﺪ ﻫﺎي ﭼﺮب ﭼﻨﺪ ﻏﯿﺮ اﺷﺒﺎع (PUFA) در ﺗﯿﻤﺎر ﮔﺮﺳﻨﻪ اﻓﺰاﯾﺶ ﯾﺎﻓﺖ و در ﭘﺎﯾﺎن دوره ﺗﯿﻤﺎر 1 ﺑﺎ دﯾﮕﺮ ﺗﯿﻤﺎر ﻫﺎ اﺧﺘﻼف ﻣﻌﻨﯽ داري را ﻧﺸﺎن داد(0.05>p ). ﻣﯿﺰان n3 در ﺗﯿﻤﺎر ﻫﺎي ﮔﺮﺳﻨﻪ ﺗﻐﯿﯿﺮ ﭼﻨﺪاﻧﯽ ﭘﯿﺪا ﻧﮑﺮد وﻟﯽ ﻣﯿﺰان 6 nﮐﺎﻫﺶ ﯾﺎﻓﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﺎﻫﯽ ﻗﺰل آﻻي رﻧﮕﯿﻦ ﮐﻤﺎن ﻣﯽ ﺗﻮاﻧﺪ در دوره ي ﮔﺮﺳﻨﮕﯽ از ذﺧﺎﯾﺮ(MUFA) ﺧﻮد ﺑﺮاي ﺟﺒﺮان دوره ي ﮔﺮﺳﻨﮕﯽ ﺗﺎ رﺳﯿﺪن ﺑﻪ دروره ي ﺗﻐﺬﯾﻪ ﻣﺠﺪد اﺳﺘﻔﺎده ﮐﻨﺪ.

In this research, the effects of starvation and refeeding on the fatty acid profile of rainbow trout have been investigated. A group of 240 trout juveniles were distributed in 12 of 150 L tanks. In this study, there were 4 treatments and 3 replications that were tested with two different fat diets. Treatment 1 fish fed 10% fat diet with 2 weeks of starvation, treatments 2 fish fed with 20% fat diet with 2 weeks of starvation. Treatment 3 fish fed a 10% fat diet without starvation and treatment 4 fish fed with 20% fat diet without starvation. After various nutritional periods, the fatty acid composition of the body was measured by the GC device. According to the results, the sum of monounsaturated fatty acids (MUFA) after the period of starvation increased compared to the fed diet and decreased at the end of the course. In contrast, the amount of unsaturated fatty acids (PUFA) increased in starvation and treatment1 showed a significant difference with other treatments at the end of period (p<0.05). N3 levels did not change significantly in starvation treatments, but decreased by n6. The results showed that Rainbow trout could use its MUFA reserves to starve to recover to the recharge during the period of starvation.