| Crystalline amino acids (CAA), as a kind of feed additives, the nutrition in aquatic animal feed has been widely used. Supplementary CAA to balance the feed AA composition, can expand the various protein source, reduce feed protein content in the application of aquatic feed formula. However, the effects of supplementation crystalline amino acids in the shrimp feed on shrimp growth and feed utilization efficiency were not achieved the desired results. Therefore, this paper studies the microencapsulation preparation process of CAA (methionine, lysine as shrimp nutritional additive) and their sustained-release mechanism;optimized parameters of extrusion cooking process for aquatic sinking pellets; illustrated the physical properties changes and water stability of the different forms of amino acids in feed processing (rotating ring die pelleting and extrusion cooking process); Verify the animal protein source (meat and bone meal and spray drying blood protein powder, lack of methionine) diet substitute for fish meal or a different protein level on growth performance and feed utilization of Litopenaeus vannamei and Macrobrachium rosenbergii. Crystalline amino acids would improve the application results in shrimp feed, and expand other types of protein sources alternative to fish meal and reduce the dietary protein content, increase feed protein utilization efficiency, in order to provide the low consumption, high-efficiency, low-carbon farming in aquatic animals and aquatic feed production. The main contents are as follows:Using spray drying, with gelatin and sodium alginate composite material of wall, for preparation of microencapsulation methionine, could be absorbed and utilized in shrimp feeds. Through twice orthogonal test, confirmed which used the alginate and gelatin as wall materials, the methionine powder as core material and spray drying technology. Results showed that the best parameters of the embedding of the microcapsule were that the 1% alginate and 1% gelatin, the methionine powder was 15%, the feed temperature was 65?, the air inlet temperature was 195?and the air outlet temperature was 80?, the feed speed was 45 mL/min, and the embedding rate reached to 89.6%. Scanning Electron Microscopy (SEM) has been applied to the observe particle shape, which was of evener, smooth surface and uniformity. Microencapsulated methionine prevent the rapid loss in the water, and slow down the absorption of shrimp juice.Prepared microencapsulation lysine-HCl by fluidized bed air suspension, optimized process conditions were determined: the wall materials were respectively zein and acrylic acid resin mixture of 10% (75% ethanol concentration, 3% oleic acid and 5% TEC as a plasticizer Zein and Resin coating solution, respectively), coating room temperature 45?, coating liquid speed 100 mL/min and spray pressure 1.2 Pa. Under these conditions, Zein microencapsulated rates and Resin microencapsulated rates were 82.3% and 80.3%, respectively. The SEM observation indicated particles irregular in shape, size distribution broad, smooth surface, no crystal edges and corners, suggesting that the shape of irregular, good embedding results. Two microencapsulation lysine-HCl in 60 min, the accumulation of dissolved lysine release rate was only 16.6% (Zein) and 32.8% (Resin), was significantly lower than at the same time crystalline lysine-HCl.The formula aquafeed was producted by extrusion cooking technology using a corotating twin-screw extruder, physicochemical properties (expansion ratio, sink rate, bulk density, starch gelatinization and pellet water stability index) of sinking aquafeed using as important index. The results showed that feed moisture content, barrel temperature and screw speed all affected physicochemical properties of extruded aquafeed significantly. Desirable products, characterized by low expansion ratio (1.15), while high bulk density (754.7 g/L), starch gelatinization (882.3 g/kg), pellet durability (96.6%) and water stability index (89.1%), were obtained at medium to high feed moisture content, barrel temperature and low screw speed. SEM examination showed that the microstructure of pellets was smooth and firm, when they producted in the optimal conditions (feed moisture content 30%, barrel temperature 120?and screw speed 80 r/min).The effects of rotating ring die pelleting and extrusion cooking process for CAA and MAA content was different. Lysine loss of Rotating ring die pelleting process was higher crystalline lysine than microencapsulation lysine, but methionine loss was not affected by rotating ring die pelleting process. The results showed, conditioning had a greater impact on loss of lysine and a smaller on microencapsulation lysine. Extrusion cooking process, extrusion temperature of feed CAA lost bigger, with the rise of temperature(60?to 150?), crystalline amino acids tended to increase the amount of loss, the loss of the crystalline lysine were 6.43%, 9.83%, 18.74% and 26.66%, respectively. The loss of crystalline methionine were 1.73%, 7.89%, 8.47% and 9.94%. Extrusion temperature less influence on MAA loss. Therefore, in the feed processing process, high temperature can make the feed C - Lys than C - Met listed to occur maillard reaction, which is likely to be the main reason caused CAA loss. Extrusion temperature affected on the loss of microencapsulation amino acids smaller. Relative to the process, crystalline amino acids lost greater in the water. In water leaching 60 min of pellets, crystalline lysine of different extrusion temperature feed dissolved lost 23.99%?40.68% greater than microencapsulation lysine. Compared with microencapsulation methionine, crystalline methionine dissolved more loss of 9%?13.5% than methionine; in water leaching 120 min of pellets, crystalline lysine of different extrusion temperature feed dissolved more loss of 24.42%?43.22% than microencapsulation lysine. Compared with microencapsulation methionine, crystalline methionine dissolved more loss than methionine of 10.45%?17.47% solution. As to feed processing and feeding feed on shrimp, the use of microencapsulation amino acids, reducing dietary amino acid dissolved dissolution in water is very important.A study was conducted to evaluate the effects of different levels of dietary meat and bone meal (MBM) supplemented with microencapsulated DL-methionine (M-Met) on the growth,digestibility of feed nutrients, feed utilization, body composition of the shrimp juvenile (Litopenaeus vannamei 0.91 g). Six iso-nitrogenous diets formulated by replacing equal nitrogenous fish meal with M-Met-supplemented MBM by 0%, 20%, 40%, 60%, 80%, and 100% for 55 days. Specific growth rates (SGR), digestibility of feed nutrients and feed utilization showed no significantly differences among shrimps when diets contained up to 60% of M-Met-supplemented MBM, However, such parameters were significantly lower for shrimps fed on diets containing 80?100% of M-Met-supplemented MBM. Compositions of crude protein, crude lipid and amino acids of shrimps among all groups at the end of the trial were not significantly affected by trial diets. It is concluded that M-Met-supplemented MBM is an acceptable alternative animal protein source, which enhances apparent digestibility of feed nutrients and decreases feed cost.The effect of substitution of fish meal (FM) by spray-dried blood cell meal (SBCM) with microencapsulated DL-methionine (M-Met) supplementation in trial diets on growth performance, feed digestibility, amino acid retention and body composition for juvenile Litopenaeus vannamei (2.3 g) was evaluated. Shrimp were fed with six diets in which FM protein was gradually replaced by SBCM protein. Results showed that the dietary FM (25% decreased to 10%) protein could efficiently be substituted by SBCM (0 increased to 10.5%) up to 60%, without adverse effects on growth of Litopenaeus vannamei.The study was conducted to evaluate the effect of different protein levels (CP crude protein, respectively: 36%, 30% and 24%) by using crystalline amino acids or microencapsulated amino acids supplements in practical diets on the growth performance, nitrogen retention and body composition of the giant freshwater prawn juvenile (Macrobrachium rosenbergii 0.15 g). Analyzing the effect of the dietary protein level and both form amino acids on growth, immunity, nitrogen retention and hepatopancreas histology of the giant freshwater prawn juvenile interactions, in order to enrich amino acids on the growth of giant freshwater prawn juvenile in crustaceans about use of basic amino acids nutrition research. The results showed that the supplementation microencapsulated amino acids can reduce the protein content of feed, to improve growth performance of M. rosenbergii, improve feed efficiency and nitrogen deposition rate of the body and enhance immunity. However, in the low protein diet (CP 24%), regardless of any form of amino acids supplements, it adversely affected on growth performance, feed utilization, body nitrogen retention and immune system of the prawn. |
PDF Full Text Request