Influence Of Double-low Rapeseed Meal On Growth Performances And Internal Organs Of Grass Carp And Common Carp

The study was conducted on grass carp (Ctenpharyngodon idellus) and common carp (Cyprinus carpio).\n growth experiments, soybean meal (SM) and fish meal (FM) were used as basic protein source in the control diet, with 17%, 34%, 51% and 68% of double-low rapeseed meal (DLRM) to replace the protein of SM 25%, 50%, 75%, 100%, repectively in the control diet. As to another group 77.1% DLRM was used to replace total protein of SM and FM in the control diet. These diets were to feed grass carp. Soybean meal (SM) and fish meal (FM) were used as basic protein source in the control diet, with 17.4%, 34.8%, 52.2% and 69.5% of DLRM to replace the protein of SM 25%, 50%, 75%, 100%, respectively in the control diet. These diets were to feed common carp. The feed rate, specific growth rate and feed conversion were measured by the change of diets containing various percentages of in grass carp and common carp. The paraffin sections were observed to examine the instance of pathology of internal organs (intestines, livers, kidney, and thyroid). A digestibility experiments was conducted to examine t he apparent digestibility coefficient of grass carp. It was explored the optimum RM to replace the protein of SM in the fish diets. The main results were summarized as follows:1 .Weight growth rate and specific growth rate of test group III (comprising 34% DLRM ) was the biggest in the test groups of grass carp; the feed conversion ration was the smallest; and had no significant differences relative to control group, the feed rate of test group II (comprising 51 % DLRM ) was biggest in test groups of grass carp.2.Weight growth rate and specific growth rate of test group II (comprising 17.4% DLRM ) was the biggest in all groups of common carp; the feed conversion ration was the smallest; the feed rate of test groupIII (comprising 34.8% DLRM ) was biggest in all groups of common carp.3. The apparent digestibility coefficient of dry matter, crude protein and crude lipid decreased with the increasing of DLRM level. The apparent digestibility coefficient of dry matter, crude protein and crude lipid at DLRM level of 25%-75% were lower than the control, but no significant differences, were significantly higher than the DLRM level of 100% and the group without FM.4. Histological of internal organs examination: in the 28th day, Vacuole form and passivation of villus intestinalis, Light hyaline droplets in kidney of the grass carp fed containing 68% and 77.1% DLRM. In the 42nd day, Vacuole form and significantly passivation of villus intestinalis, congest in liver, hyaline droplets and granular degeneration and congest in kidney, thyroids were clear hyperplasia of the grass carp fedcontaining 51%, 68% and 77.1% DLRM.5. In the 28th day, Vacuole form and passivation of villus intestinalis, hyaline droplets in kidney, of the common carp fed containing 52.2% and 69.5% DLRM. In the 42th day, Vacuole form and significantly passivation of villus intestinalis, congest and vacuolar degeneration in liver, hyaline droplets and granular degeneration and congest in kidney thyroids were clear hyperplasia of the common carp fed containing 34.8%, 52.2% and 69.5% DLRM.It is concluded that DLRM are good protein supplements, the level of DLRF can be up to 51% in 28 days and can up to 34% in 56 days for grass carp fed diets. It can be up to 34.8% in 28 days and can up to 17.4% in 56 days for common carp fed diets. Internal organs of grass carp and common carp had no pathology.