Digestion And Absorbtion Of Woody Forages By Nile Tilapia Oreochromis Niloticus

The aim of the study was to investigate the digestion and absorbtion of four woody forages,Morus alba L.,Broussonetia papyrifera,Moringa oleifera Lam.and Neolamarckia cadamba,in Nile tilapia Oreochromis niloticuswhich would provide the scientific basis for the application of four woody forages in tilapia feed.1.Apparent digestibility coefficients(ADCs)of the four woody forages in Nile tilapia Oreochromis niloticus were investigated.The test feeds were made with 70% of reference feed and 30% test ingredients,respectively,in which 0.1% of yttrium oxide were added as indicator.Tilapia with initial body weight of 100±10 g were randomly stocked into 5groups and each group had 3 replicate tanks with 10 fishes in each tank.Fish were fed feeds two times daily.After 1 week of feeding,feces in each tank were collected and dried and stored for later analysis.The results showed that the ADCs of crude lipid(83.66%),dry matter(82.54)and gross energy(82.92%)of Neolamarckia cadamba were significantly higher than those of other three groups(P < 0.05),and those of Morus alba L.,Broussonetia papyrifera were lower,and those of Moringa oleifera Lam were the lowest.And the trend of ADCs of crude protein and amino acid were similar.The ADCs of total phosphorus(75.85%)of Neolamarckia cadamba was the highest.The results showed that these four woody foragescould be applied in feed of Nile tilapia.2.Effects of the four woody forages on serum biochemical indicators of Nile tilapia Oreochromis niloticus.Serum glucose,urea,triglyceride,total cholesterol,total protein,albumin,alanine aminotransferase,aspartate aminotransferase,high-density lipoprotein,and low-density lipoprotein were determined.After six weeks of feeding,the fish were starved for 24 h,and serum was collected and 10 biochemical indicators were measured.The results showed that the serum total protein,triglyceride,and low-density lipoprotein of tilapia were significantly higher than those of reference feeds in Moringa oleifera,Mulberry leaf,Scutellaria barbata,and Hibiscus leaf.The serum urea and aspartate aminotransferase activities of the four groups of woody feed were significantly lower than those of thereference feed.Serum albumin and reference feed serum albumin,serum total cholesterol,high-density lipoprotein assay,glucose,alanine aminotransferase in each group no significant difference.The results shown that adding Moringa oleifera leaf powder,mulberry leaf powder,huangliangju leaf powder,and buckwheat leaf powder to the diet had no influence on liver function,and could promote serum fat metabolism.3.Effects of four woody feed ingredients on intestinal protease and amylase activity of Nile tilapia.The results showed that there were no significant differences in the protease activity of the fore,middle and hind intestines of the other groups except for the fore intestine of the Moringa group.There were no significant differences in amylase activity among groups.4.The effects of four woody feedstuffs on the intestinal structure of Nile tilapia.The results showed that the mulberry leaf had no significant effect on the intestinal villus height of Nile tilapia,and the Moringa officinalis,Huangliangmu,and Zhishu significantly reduced Ni.The intestinal villus height,the Moringa oleifera,and the Huangliangmu had no significant effect on the intestinal muscle thickness of Nile tilapia.The thickness of the intestinal muscle layer of Nile tilapia was significantly different between Broussonetia papyrifera and Mulberry leaves.Experiments show that,from the aspect of apparent digestibility,four kinds of woody feeds are suitable as tilapia compound feed materials,and Huangliangmu is most suitable.From the perspective of serum biochemical indicators,four woody feeds have the ability to promote liver function,promote fat metabolism,promote renal excretion,and reduce protein catabolism.In addition,Moringa can significantly affect the proteasome activity of Nile tilapia.Mulberry leaf and mulberry tree can significantly increase the intestinal muscle thickness of Nile tilapia.