饲料中添加晶体或包膜氨基酸对异育银鲫生长和血清游离氨基酸水平的影响

进行了二个试验考察饲料中添加晶体或包膜氨基酸对异育银鲫生长和血清游离氨基酸水平的影响。试验Ⅰ设计了鱼粉含量为18%和9%的两种基础饲料(分别为高鱼粉对照组、低鱼粉对照组),在低鱼粉对照组中分别添加晶体形式、环糊精包膜、淀粉包膜的赖氨酸0.23%、蛋氯酸0.09%,饲养平均体重2.48 g的异育银鲫鱼种6周。结果表明,高鱼粉对照组、低鱼粉对照组、晶体氨基酸组、环糊精包膜氨基酸组、淀粉包膜氨基酸组的鱼体增重率分别为214.3%、169.8%、173.3%、204.7%、203.2%,与低鱼粉对照组相比,添加晶体氨基酸对异育银鲫的生长无改善(P>0.10),但添加环糊精包膜或淀粉包膜氨基酸提高了鱼体增重率20.5%、19.7%(P<0.05),饲料系数下降0.40、0.39(P<0.05)。试验Ⅱ在鱼粉含量为6%的基础饲料分别添加晶体形式、环糊精包膜、淀粉包膜的赖氨酸0.20%、蛋氨酸0.08%,在异育银鲫成鱼(平均体重220 g)摄食上述4种饲料后1、3、5、12h,尾静脉采血测定血清游离氨基酸浓度,结果表明,添加晶体氨基酸使血清游离氨基酸的吸收峰值提前,相对于晶体氨基酸而言,环糊精包膜或淀粉包膜氨基酸则使血清游离氨基酸的吸收峰值出现不同程度的延迟。上述研究表明,晶体氨基酸经环糊精、淀粉包膜处理后,其在消化道的吸收速度减缓,可利用性显著提高。

Supplemental effects of crystalline or coated amino acids on growth performance and serum free amino acids of Allogynogenetic crucian carp

Two experiments were conducted to investigate the effect of adding crystalline or coated amino acids in diets on growth performance and serum free amino acids of allogynogenetic crucian carp.In Exp.1, five diets,including high or low fish meal diets(containing18% or 9% fish meal,respectively),low fish meal diet added with 0.23% Lys and 0.09% Met of crystalline,dextrin coated and starch coated styles, were designed to feed allogynogenetic crucian carp fingerling with initial body weight of 2.48 g for 6 weeks.Growth rates of the five groups were 214.3%,169.8%,173.3%,204.7% and 203.2% respectively.Compared with low fish meal control diet,there was no significant effect of adding crystalline amino acid on growth performance,but growth rate was improved by 20.5%,19.7%(P<0.05)and feed coefficient was decreased by 0.40,0.39(P<0.05)by adding dextrin or starch coated amino acid.In Exp. 2,basal diet(6% fish meal)was added without or with 0.21% Lys and 0.08% Met of crystalline,dextrin coated and starch coated styles.Then serum free amino acids were determined 1,3,5,12 h after allogynogenetic crucian carp(body weight of 220 g)intaking diets.Results showed that serum free amino acids absorbing peak values were advanced by adding crystalline amino acids,but delayed by adding coated amino acids compared with crystalline amino acid.Results above showed that crystalline amino acids' absorbing velocity in digestive tract could be delayed and their availability improved by coating with dextrin or starch.