Study On Preparation And Application Of Dog Food With High Content Polyunsaturated Fatty Acids

The main purpose of this paper is to develop a kind of high quality dog food which canmeet the market demand. In order to improve the health of the pet dog’s hair and skin,polyunsaturated fatty acids was supplemented to the pet dog diet by adding linoleic acid andlinolenic acid.The primary ingredients and nutrient addition levels of the recipe were set according to thenutrition standards of dogs of AAFCO in the United States and the composition of maincommercial products of particle dog foods. The formula was optimized by using the relatedrestrictive requirements of the linear programming in Excel and considering the material price.The optimal product composition was as follows: fresh chicken, fish meal, soybean meal, oil,rice, wheat, the original grain of corn, yeast powder, calcium hydrogen phosphate, vitaminand mineral premix etc.The influences of the barrel temperature, moisture content and screw speed on the qualityof extrusion dog food were investigated based on the optimized formula with proteindigestibility and gelatinization degree as the factors. The best combination of these threeparameters was obtained by single factor experiment and orthogonal experiment: barreltemperature was80-100-130-140℃, moisture content was26%and the screw speed150r/min. The combination of the protein materials was further optimized on the basis ofoptimized formula with protein digestibility and amino acid levels as the index. The bestproportion was10%chicken+18%soybean+10%fish meal in consideration of proteindigestion rate, amino acid level and cost.The experimental results showed that adding4%oil would make the gelatinization ofstarch decrease to90, and choose spraying oil after extrusion process. To improve the contentof the linolenic acid of the dog food, adding4%flaxseed before the extrusion made thecontent of the linolenic acid reach1.23%, storage experiments also proved that the loss oflinolenic acid by adding flaxseed before extrusion was less than10%, while the loss would bemore than50%by spraying linseed oil after extrusion process. Above all, we added flaxseedbefore extrusion and sprayed linseed oil after extrusion to increase the content ofpolyunsaturated fatty acids of dog food.In order to verify the improvment of polyunsaturated fatty acids on dog hair and skin,15adult beagle dogs (9female) were divided into three groups of animal experiments: linolenicacid group (5.29%linoleic acid,1.23%linolenic acid)、 linoleic acid group (5.05%linoleicacid,0.10%linolenic acid)、control group(1.26%linoleic acid,0.13%linolenic acid), theexperimental period is84days. The results showed that the sensory score of skin and hair0flinolenic acid group and linoleic acid group had been significantly improved compared withcontrol group,; the score of the hair and skin of linolenic acid group respectively increased by26.4%and17.6%, the linoleic acid group was19.3%and13.7%; the score of the skin of thelinolenic acid group was slightly better than that of linoleic acid group(2.54±0.05VS2.34±0.12). Results of serum phospholipids unsaturated fatty acid in experimental dogs, the relativecontent of linoleic acid、 linolenic acid and arachidonic acid of linolenic acid group had been increased by390%、25.34%、-0.5%; linoleic acid group was164%、15.3%、7%. Above all,we found that the improvement in the hair and skin of the experimental dog improvement hadobvious correlation with polyunsaturated fatty acids...