Nutrient Value Of Waste Vinegar Residue And Its Effects On Nitrogen Excretion In Laying Hens

This thesis included four parts. Firstly, waste vinegar residue (WVR) samples were collected fromvinegar factories located in different areas of the Shanxi province and prepared for evaluation of basicnutrient components. And then, apparent metabolizable energy of WVR was evaluated. Moreover,different amounts of WVR were included in a corn-soybean meal-based diet and nutrient digestibilityand nitrogen excretion were measured. At last, the influence of WVR on microbiaota profile of layinghens was evaluated to explore the underlying mechanisms for the alleviating effects of WVR onnitrogen excretion in laying hens.Exp.1Sample collection and nutrient components evaluation of waste vinegar residueTwelve representative WVR samples were collected in Taiyuan city, Qingxu county, Yuci countyand Taigu county of Shanxi province in order to evaluate moisture, gross energy, nertral detergent fiber,acid detergent fiber, acid detergent lignin, crude protein, ether extract, ash, amino acids, trace elements,starch and organic acids. The results showed that the average of original moisture content was70.92%.WVR was riched in fiber with the74.98%of neutral detergent fiber and52.51%of acid detergent fiber.Crude protein and starch content of WVR were12.38%and19.26%, respectively. Organic acids inWVR included acetic acid, lactic acid, malic acid, tartaric acid and α-ketoglutaric acid with total amountof2273.96mg/kg. There was great variation in nutrient among different WVR samples with variablecoefficient value of most traits more than10%.Exp.2Evaluation of apparent metabolizable energy of waste vinegar residue in laying hensThe aim of this study was to evluated apparent metabolizable energy (AME) of WVR in layinghens. The AME value and the nitrogen-corrected apparent metabolizable energy (AMEn) of WVR werestudied by feeding hens with a complete corn-soybean meal basal diet and three other diets inwhich10%,15%, and20%of the energy-and amino acid-yielding ingredients (corn,soybean meal, soy oil, and DL-methionine) of the basal diet were replaced with WVR. Theregression of WVR-associated ME intake in kcal against WVR intake in kg generated the followingequation: Y=650.01X-7.94, r~2=0.930, which indicated an AME value of650.01kcal/kg for the WVR.The regression of WVR-associated AMEn intake in kcal against WVR intake in kg generated thefollowing equation: Y=716.01X–8.90, r~2=0.910, which indicated an AMEn value of716.01kcal/kgfor the WVR. Exp.3Effects of inclusion of waste vinegar residue in the diet on nitrogen excretion in laying hens0%,2%,4%, and6%of WVR were included in a corn-soybean meal-based diet with the samelevel of metabolizable energy, crude protein, methionine and lysine among different diet and nutrientdigestibility and nitrogen excretion were measured. During the12-d period, nitrogen intake, nitrogenexcretion, uric acid nitrogen and ammonium nitrogen were evaluated in laying hens. The results showedthat inclusion of2%WVR in the diet did not affect the digestibility of energy, neutral detergent fiber,acid detergent fiber and crude protein. Diet including4%of WVR increased total tract apparentdigestibility (TTADs) of nitrogen (P＜0.01) of hens. Inclusion of6%of WVR in the diet resulted inlower TTADs of dry matter (P＜0.01). Inclusion of4%of WVR in the diet significantly decreased thenitrogen excretion (P＜0.05) and uric acid N excretion (P <0.01). Inclusion of6%of WVR in the dietsignificantly decreased uric acid excretion (P＜0.01) and uric acid nitrogen (%of N excretion, P＜0.01).Exp.4Effects of inclusion of waste vinegar residue in the diet on intestinal microflora of layinghensIn this trial, three experimental diets, including a corn and soybean meal-based control diet andtwo other diets formulated with2%and4%of WVR were fed to laying hens for27days. All of thediets were formulated with the same level of metabolizable energy, crude protein, methionine and lysine.DNA was extracted from digesta in ileum and cecum of laying hens,16S rDNA V3region wasamplified by PCR and denaturing gradient gel electrophoresis (DGGE) was performed. The resultsshowed that inclusion4%of WVR reduced the number of DGGE bands and Shannon index for ileumand cecum (P <0.01). Inclusion of2%WVR had no significant effect on the number of DGGE bandsand Shannon index for ileum and cecum.