Effects Of Linseed Oil On Growth Performance, Lipid Metabolism And Antioxidant Capacity Of Common Carp

The high-energy and low nitrogen feed is necessary for efficient, sustainable development of the aquaculture industry. As the aquatic feed branded oil source, fish oil has been acclaimed, However, because of its resources and prices, forcing the feed companies seek other alternative fat sources. Flax is one of the world’s top ten oil-bearing crops, linseed oil is a rich source of unsaturated fatty acids, the alpha linolenic acid have a series of important physiological functions. So, the linseed oil is the high-quality source of potential aquatic feed. The study is divided into two test. first, one is the comparison of linseed oil, fish oil, canola oil, soybean oil, lard respectively as the single source of carp effect on growth performance of lipid metabolism and antioxidant capacity, in order to evaluate linseed oil as the single lipid source in the carp feed using effect; one is replace fish oil with linseed oil with0%,25%,50%,75%and100%, determination of linseed oil to replace fish oil on carp growth metabolism of lipid and antioxidant capacity, in order to find the most suitable alternative ratio, provide the basis for the scientific use of linseed oil in the carp feed.1. Effect of different lipid sources in diets on growth performance, lipid metabolism and antioxidant ability of Common CarpA feeding experiment conducted to investigate the effects of dietary lipid sources on growth, body composition, and activities of lipid metabolism related enzymes and antioxidant enzymes in hepatopancreas of common carp (initial body weight5.83±0.01g). Five isonitrogenous (crude protein35%) and isoenergetic (15kJg-1) practical diets were formulated to contain1.5%lipid originated from fish oil (FO), soybean oil (SO), rapeseed oil (RO), linseed oil (LO) and pork oil (PO), respectively. Each diet was randomly fed to triplicate groups of fish, and each tank was stocked with50fish. The experiment lasted for8weeks. The results showed as follows:Specific growth rate (SGR), protein efficiency ratio (PER) and feed conversion ratio (FCR) of fish fed FO were significantly superior to SO, RO and LO group, the lowest in PO group (P<0.05). Carcass protein was the highest in FO group (P<0.05), but its carcass lipid was the lowest (P<0.05). No significant difference was found among all treatments in carcass ash and moisture (P>0.05). The activities of lipoprotein lipase (LPL) was the highest in FO group, followed SO、RO and LO, the lowest in PO group (P<0.05). The activities of malic dehydrogenase (MDH) show that LO>SO>FO>RO>PO (P<0.05). No significant difference was found among all treatments in superoxide dismutase (SOD)(P>0.05), but no significant effect total antioxidant capacity (T-AOC)(P<0.05), the highest in FO group, the lowest in PO group. These results suggested that FO was the suitable lipid sources, while PO is unsuitable as single lipid sources for common carp, because it would damage the hepatopancreas health, hinder the growth of fish.2. Effect of replacing fish oil with linseed oil on the growth performance, lipid metabolism and antioxidant ability of Common CarpThe objective of this experiment was to test the effect of total or partial substitution of dietary FO by LO in common carp feeding on performance, selected lipogenic and lipolytic enzyme activities, liver oxidative stability. For8week, fish (initial body weight5.81±0.03g) were fed five experimental diets in which the FO was serially replaced by25,50,75, and100%LO. The results showed as follows:As linseed oil to replace fish oil level increases, the carp in the SGR showed a trend of decrease after the first increases, The FCR is just the opposite. the Diet2(25%) group have the highest SGR, significantly higher than Diet4(75%) group and Diet5(100%) group (P<0.05). No significant difference was found among all treatments in PER(P>0.05). Dietl (0%) group of the whole fish protein content is significantly higher than the other group (P<0.05), while the crude fat content was the lowest (P<0.05). No significant difference was found among all treatments in carcass ash and moisture (P>0.05). With the increase of LO to replace fish oil level, the experimental group carp liver pancreas of LPL activity and T-AOC) reduced (P<0.05, liver and pancreas MDH activity increased (P <0.05), whereas the had no effect on the activity of SOD (P>0.05). Thus, LO instead of different level of FO on carp growth metabolism and antioxidant power will have a significant impact. Replace fish oil with25%LO level growth showed the best effect, the harm of liver function minimum, and completely replace FO can affect the growth of carp, and the harm of liver is the largest.