الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 237 |  |  |
| | | from | 237 | | |
Abstract
The objective of this work was to evaluate the institution levels of distillers dried grains with solubles (DDGS) instead of soybean meal in laying hen diets with or without enzyme or vitamin E supplementation on the performance and egg quality traits as well as digestibility coefficient of nutrients in the diet and some biochemical blood parameters for Hisex Brown laying hens from 22 to 42 weeks of age. A 5×3 factorial design experiment was performed including five substitution levels of DDGS for soybean meal (0, 25, 50, 75 and 100 % respectively) and three levels of feed additives (without, 250 mg enzyme/kg diet or 200 mg vitamin E/ kg diet) through 22- 42 weeks of age. A total number of 180 Hisex Brown laying hens 22 weeks old were randomly divided into 15 treatment groups of 12 hens (4 replicates/ treatment and 3 hens / replicate).The results obtained showed that increasing DDGS substitution level more than 75% decreased (P≤0.01) values of body weight change, feed intake, feed conversion, egg number and egg mass. Where, replacing soybean meal by 25% DDGS gave the best (P≤0.01) values of final body weight, body weight change, feed intake, egg weight and egg mass throughout the whole experimental period (22-42 weeks of the age). All egg quality criteria and egg constituents studied were significantly influenced (P≤0.01) by DDGS replacement levels. Significant (P≤0.01) effects due to DDGS substitution levels were observed on all serum constituents determined except albumin, HDL and phosphorous. Serum total protein, albumin and globulin increased when hens fed on 25% DDGS substituted for soybean meal. Digestion coefficient values of nutrients were more preferable in hens fed diets contained 25% DDGS instead of soybean meal than that of the control diet and other treatment groups. Feeding 75 or 100% DDGS as a replacement of soybean meal led to an increase in nitrogen excretion. Whilst, the amount of excreted phosphorous was markedly (P≤0.01) decreased as the level of DDGS increased. Generally, the effects of feed additives and the interaction between DDGS levels and feed additives were significantly (P≤0.05 or P≤0.01) altered all studied parameters except for the majority of blood parameters, digestibility coefficients and feeding values or nitrogen and phosphorous excreted. With regard to the economical evaluation, Hens fed diet contained 50 % DDGS substituted for soybean meal with vitamin E supplementation resulted in the best economical efficiency (116.29%) followed by hens fed the control diet with enzyme supplementation (116.19%). from this study, it could be concluded that DDGS as an alternative feedstuff instead of soybean meal could be used in laying hen diets up to 50 %. Also, diet contained 50 % DDGS substituted for soybean meal and supplemented with 200 mg vitamin E/ kg diet was economically the best.