A study was conducted to evaluate efficacyof wheat based vs. corn based diets on growth performance, carcass traits,blood parameters, jejunum morphological development, immunity, cecal microflora and excreta moisture in broiler chicks fed according to digestible essential amino acid profile. One hundred forty day old Ross 308 male broiler chicks randomly distributed into ten separated floor pensbased on a completely randomised design. Each treatment consisted of five replicates with fourteen birds each.Body weight (BW), body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), immunity and excreta moisture were determined at different periods of ages. At the day 44, five birds of each group were sacrificed to evaluated carcass traits, jejunum histomorphology and cecal microflora. Blood parameters, mortality rate (MR) and European production efficiency factor (EPEF) were measured and determined at day 42 of age, respectively. The results of this study showed that BW, BWG, FI, FCR, MR and EPEF were not significantly different between two groups on the day 42 of age, but BW, BWG and FI were significantly higher (P<0.05) in corn based than wheat based diets on starter phase of feeding and also FI and FCR on the growing phase. Most ofcarcass traits were not significantly different(P>0.05) between two groups except for abdominal fat (AF) percentage which was significantly higher (P<0.05) in corn-based diet. Despite a reduction of triglyceride, total cholesterol, high density lipoprotein (HDL) and low density lipoprotein (LDL) concentration in the serum of broilers fed thewheat base diet, there were no statistically significant differences between two groups (P>0.05). Humeral immunity response, Newcastle titer, jejunum histomorphology, cecal microflora and excreta moisture were not significantly different (P>0.05) between two groups. In conclusion, wheat based diet is as efficient as corn based diet when diets are formulated based on digestible amino acids method. پرونده مقاله

This study was conducted to assess the effects of feed particle size (FPZ) and crumble size (CZ) of starter diet on growth performance parameters, carcass characteristics, and small intestinal histomorphology in broiler chicks. Three hundred and sixty male Ross 308 chicks were randomly distributed in a completely randomized design with 3 ´ 2 factorial arrangement consist of three screened FPZs (500, 1000 and 1500 µm) and two CZs (1.5 and 2.5 mm). Each treatment included six replicates (10 broiler chicks per cage) and chicks were reared in the cage from 0-10 d of age. The results indicate that neither main factors nor interaction between FPZ and CZ had any significant effect on body weight (BW) and European production efficiency factor (EPEF) at 10 d. However, a significant interaction effect (P<0.05) between FPZ and CZ were observed for feed intake (FI), feed conversion ratio (FCR) and feed efficiency (FE). FPZ had a significant effect (P<0.05) on gizzard relative weight. Increasing FPZ significantly (P<0.05) increased gizzard relative weight. Both FPZ of 1500 µm and CZ of 2.5 mm numerically caused FI reduction, improved FCR, FE, increased EEPF and reduced abdominal fat weight. The CZ had significant (P<0.05) effect on relative gizzard muscular thickness. As the CZ increased, the relative gizzard muscular thickness significantly (P<0.05) decreased. The effect of CZ on villous high (VH) of ileum was significant (P<0.05). Indeed, as the CZ increased, the VH of Ileum significantly decreased (P<0.05). A significant interaction (P<0.05) between FPZ and CZ was seen in FI, FCR, FE, gizzard relative weight and relative gizzard muscular thickness, absolute fat weight of gizzard. In the diet made from the FPZ of 1500 µm and CZ of 1.5 mm FI significantly (P<0.05) reduced, FE and FCR significantly (P<0.05) improved. In conclusion, birds fed coarsely FPZ (1500 µm) and smaller CZ (1.5 mm) diet showed better FCR and FE which was due to enhanced gizzard development and intestinal histomorphology parameters. پرونده مقاله

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