鲈鱼对7种饲料原料的表观消化率及其对肝脏、肠道组织结构的影响

Effects of seven feed ingredients on growth performance,and liver and intestine histology of Lateolabrax japonicas

试验以Cr2O3为指示物,以70%基础饲料和30%的待测饲料原料组成试验饲料,在室内流水养殖系统中,采用虹吸法收集粪便,测定了初始体重为30±2.3 g的鲈鱼Lateolabrax japonicus对白鱼粉、血粉、虾糠、羽毛粉、双低菜粕、高筋粉和米糠中干物质、粗蛋白和能量的表观消化率。试验结果表明,鲈鱼对不同饲料原料的干物质表观消化率为98.71%~41.84%。其中白鱼粉为98.71%,显著高于其他各组（P〈0.05）。鲈鱼对白鱼粉和米糠的蛋白表观消化率很高,均在98%以上,双低菜粕也较高,为86.86%,血粉、羽毛粉和高筋粉在62.94%~71.08%之间,虾糠仅为45.01%,显著低于其他各组（P〈0.05）。鲈鱼对不同饲料原料的能量表观消化率为95.24%~65.54%,对白鱼粉和高筋粉在90%以上,对血粉、羽毛粉、双低菜粕和米糠的能量表观消化率在74%以上。进行70 d的饲养实验后,取鲈鱼肝脏和肠道组织制作切片。观察到血粉、羽毛粉、双低菜粕、高筋粉和米糠对鲈鱼肝脏表现出肝损害所致的组织炎症反应、肝细胞水样变性和脂肪变性等病理特征。血粉、羽毛粉、双低菜粕组鲈鱼肠道皱襞出现顶端上皮细胞脱落、炎症细胞浸润等病理症状。

A digestive experiment was conducted on Japanese sea bass Lateolabrax japonicus weighing 30±2.3g at 23±2℃.Chromic oxide（Cr2O3） was used as the inert indicator.The apparent digestibility of dry matter,protein,lipid,energy,and amino acids in seven feed ingredients（white meal,blood meal,shrimp meal,feather meal,double low rapeseed meal,high-gluten flour,and rice bran） were determined.The test diets were composed of 70% reference diet and 30% test ingredient.The results showed that the apparent digestibility of dry matter was in the range of 98.71%~41.84%,among which the fish meal（98.71%） was the highest compared to the others.Digestible protein from these ingredients was in the range of 45.01%~86.86%,comparatively,above 98% for fish meal and rice bran.The assimilation of energy was the highest in the fish meal（95.24%） and the lowest in the shrimp meal（65.54%）.The liver histology has been affected by the diets containing blood meal,feather meal,double low rapeseed meal,high-gluten flour,and rice bran after 70 days experiment.The lesions occurred,including fatty degeneration and leukocyte of infiltration in the hepatic tissue,and aquatic degeneration,etc.With blood meal,feather meal,and double low rapeseed meal replacements,pathological disruption of intestine was observed,characterized by sloughing of epithelium cell and increasing amounts of leukocytes in it.