80%赖氨酸硫酸盐与98%赖氨酸盐酸盐对生长中期草鱼生长性能、消化吸收能力和消化器官生长发育影响的比较研究

本试验通过比较80%赖氨酸硫酸盐80%L-Lys·H2SO4,简称80赖氨酸(80-Lys)]与98%赖氨酸盐酸盐98%L-Lys·HCl,简称98赖氨酸(98-Lys)]对生长中期草鱼生长性能、消化吸收能力和消化器官生长发育的影响,探讨80-Lys和98-Lys在草鱼上的生物效价并确定以80-Lys为赖氨酸(Lys)添加形式时饲料中Lys的适宜含量。选择初始体重为275.80 g左右的健康草鱼540尾,随机分成6组(每组3个重复,每个重复30尾鱼),分别饲喂Lys含量为0.8%(基础饲料)、1.0%、1.2%、1.4%和1.6%的添加80-Lys的饲料及Lys含量为1.2%的添加98-Lys的饲料60 d。结果表明:与基础饲料相比,饲料中添加适宜水平的80-Lys使饲料Lys含量达到1.2%时可显著提高生长中期草鱼的增重率(W GR),特定生长率(SGR),采食量(FI),全肠脂肪酶、淀粉酶活力,肝胰脏谷草转氨酶(GOT)和谷丙转氨酶(GPT)活力,前、中、后肠碱性磷酸酶(AKP)、肌酸激酶(CK)活力,肝体指数与肠体指数以及前、后肠皱襞高度(P0.05),显著降低血清GOT和GPT活力(P0.05),且80-Lys对上述指标的作用效果显著优于98-Lys(P0.05);此外,还可显著提高生长中期草鱼的饲料效率(FE),全肠胰蛋白酶活力,前、中、后肠Na+,K+-ATP酶(Na+,K+-ATPase)和γ-谷胺酰转肽酶(γ-GT)活力,肠长与肠长指数以及中肠皱襞高度(P0.05),但80-Lys对上述指标的作用效果与98-Lys差异不显著(P0.05)。由此得出,与98-Lys相比,80-Lys能更有效地提高生长中期草鱼的消化吸收能力,进而促进其生长。以80-Lys为Lys添加形式,以SGR和FE为标识,生长中期草鱼(276~667 g)饲料中Lys的最适含量分别为1.31%(占饲料蛋白质的4.68%)和1.27%(占饲料蛋白质的4.54%)。

A Comparative Study: Effects of 80% L-lysine· H2SO4 and 98% L-lysine· HCl on Growth Performance,Digestion and Absorption Capacities and Growth Development of Digestive Organs of Young Grass Carp ( Ctenopharyngodon idella)

This study aimed to compare the effects of 80% L-lysine· H2SO4 (80-lysine) and 98% L-lysine· HCl ( 98-lysine) on growth performance, digestion and absorption capacities and growth development of diges-tive organs of young grass carp ( Ctenopharyngodon idella) , to explore the biological values of 98-lysine and 98-lysine, and to determine the optimum dietary lysine content using 80-lysine as the supplemental form of ly-sine.A total of 540 grass carp with an initial body weight about 275.80 g were randomly divided into 6 groups with 3 replicates each and 30 fish per replicate.Fish in 6 groups were fed adding 80-lysine diets containing 0.8% ( basal diet) , 1.0% , 1.2% , 1.4% and 1.6% lysine and adding 98-lysine diet containing 1.2% lysine for 60 d, respectively.The results showed as follows:compared with the basal diet, dietary lysine content reached 1.2% by adding suitable level of 80-lysine could significantly increase the weight gain rate ( WGR) , specific growth rate ( SGR) , feed intake ( FI) , the activities of lipase, amylase in total intestine, the activities of glu-tamic oxalacetic transaminase ( GOT) and glutamate pyruvate transaminase ( GPT) in hepatopancreas, the ac-tivities of alkaline phosphatase ( AKP) and creatine kinase ( CK) in proximal intestine ( PI), mid intestine ( MI) and distal intestine ( DI) , hepatosomatic index ( HSI) , intestosomatic index ( ISI) and the fold height of PI and DI ( P<0.05) , and significantly decrease the activities of GOT and GPT in serum ( P<0.05); the effects of 80-lysine on these parameters were better than 98-lysine (P<0.05).Moreover, compared with the basal diet, dietary lysine content reached 1.2% by adding suitable level of 80-lysine could significantly increase the feed efficiency ( FE ) , total intestine trypsin activity, the activities of Na+, K+-ATPase and γ-glutamyl-transferase (γ-GT) in PI, MI and DI, intestinal length, relative gut length ( RGL) and fold height in MI ( P<0.05); however, compared with 98-lysine, no significant effects of 80-lysine were observed on these parame-ters ( P>0.05) .In conclusion, 80-lysine is more effective than 98-lysine for improving growth, and digestion and absorption capacities of young grass carp.Using 80-lysine as the supplemental form of lysine, the optimum dietary lysine content for young grass carp ( 276 to 667 g) base on SGR and FE is 1.31% ( 4.68% of dietary protein) and 1.27% ( 4.54% of dietary protein) , respectively.