Effects Of Glycine On Growth,biochemical Indexes And Body Composition Of Penaeus Vannamei

Glycine is the simplest natural amino acid with the simplest structure.It can promote the growth of aquatic animals and improve its physiological functions such as antioxidant capacity.However,glycine is a non-essential amino acid for aquatic animals,so there is little research on aquatic animals.This paper takes Penaeus vannamei with an initial body weight of 4.2±0.4 g as the research object,and adds 2%,2.4%,2.8%,3.2%,3.6%,and 4% glycine to form 6 experimental feeds for 42 days of breeding.After the test,the relevant indicators of growth,digestion,immunity,antioxidant capacity and muscle amino acid composition of Penaeus vannamei were measured.The main research contents and results are as follows1.The effect of adding glycine in feed on the growth and digestive enzymes of Penaeus vannameiAdding 3.6% glycine to the feed can significantly increase the weight gain and specific growth rate of Penaeus vannamei(P<0.05)。 No significant effect on survival rate,feed coefficient and fullness(P>0.05),but compared with the control group,the feed coefficient of the experimental group showed a downward trend.The addition of 3.2% glycine to the feed had a significant effect on the activity of hepatopancreas protease(P<0.05),and the experimental group showed an overall upward trend compared with the control group.The addition of 2.4% glycine to the feed had a significant effect on hepatopancreas amylase(P<0.05),and the amylase activity of the experimental group showed an upward trend compared with the control group.The addition of glycine to feed has no significant effect on hepatopancreatic lipase activity(P>0.05).2.The effect of adding glycine in feed on the physiological and biochemical indexes of Penaeus vannameiAdding glycine to feed significantly reduces blood acid phosphatase activity(P<0.05),but has no significant effect on blood lysozyme,alkaline phosphatase,hepatopancreas acid phosphatase and alkaline phosphatase(P>0.05).The addition of glycine to the feed increased the activity of glutathione peroxidase and catalase(P<0.05),and both reached the maximum when the added level of glycine was 3.2%.Significantly reduces the activity of superoxide dismutase(P<0.05),reaching the minimum when the added glycine level is 4.0%.No significant effect on malondialdehyde(P>0.05),but the test group showed a downward trend compared with the control group.The addition of glycine to the feed had no significant effect on the serum aspartate aminotransferase content of Penaeus vannamei(P>0.05),but the addition of glycine levels of 2.4% and 2.8% showed a decreasing trend compared with the control group;the addition of 3.2% glycine significantly increased the GPT content(P<0.05).There was no significant difference between the other experimental groups and the control group(P>0.05),but when the levels of glycine added were 2.4% and 2.8%,they showed a decreasing trend compared with the control group.3.The effect of adding glycine in feed on the nutritional composition of Penaeus vannamei.The addition of glycine to the feed significantly reduces the water content of Penaeus vannamei and increases the crude protein and ash content(P<0.05).The water content and crude protein content reach the maximum value at 3.6% glycine level,and the ash content reaches the maximum level at 4.0% glycine level.Value;there is no significant effect on the crude fat content(P>0.05),but the overall increase in comparison with the control group except for the 4.0% addition level of glycine.The addition of glycine in the feed increased the content of glycine,glutamic acid and proline in the muscle of Penaeus vannamei(P<0.05),but had no effect on the content of essential amino acids,non-essential amino acids and total amino acids(P>0.05).Significantly reduced the ratio of the total amount of essential amino acids to the total amount of non-essential amino acids and the ratio of the total amount of essential amino acids to the total amount of amino acids(P<0.05),and increased the ratio of the total amount of non-essential amino acids to the total amount of amino acids(P<0.05).The addition of glycine to the feed had no significant effect on the total amount of umami amino acids of Penaeus vannamei(P>0.05),but except for the 2.8% group which was slightly lower than the control group,the other experimental groups were slightly higher than the control group.Glycine significantly increased the content of glutamate in the muscle of Penaeus vannamei(P<0.05).Adding 3.2% glycine significantly increased the content of glutamate and glycine in the muscle of Penaeus vannamei(P<0.05).Although there was no significant effect on aspartic acid and alanine(P>0.05),it also improved to a certain extent.,Improve the umami and sweetness of the muscles of Penaeus vannamei.