eventy two New Zealand White rabbits (NZW) at 25 days of age were used to study the effect of of different dietary starch and protein levels on productive performance, nutrients digestibility coefficients, carcass characteristics, digestive tract measurements, blood constituents, enzymes activity and economical evaluation. The rabbits were fed on six experimental diets containing 3 levels of starch {16 (LS), 19 (MS) and 22% (HS)} and 2 levels of protein {14 (LP) and 16% (OP)} in a factorial arrangement design. The results obtained are summarized as follows:-Best results for live body weight (LBW) were obtained for rabbits fed 16% starch and 14% protein diet at the end of growth period (81 days of age). Decreasing of dietary starch and protein levels had a positive effect on average daily body weight gain (DBWG) in overall growth period (25-81 d.). Daily feed consumption (DFC) was affected by different levels of starch, but no protein level. Feed conversion ratio (FCR) was improved at moderate dietary starch and low dietary protein levels. Mortality rate of growing rabbits improved due to decreasing dietary protein levels. However, dietary starch levels had no effect.-Rabbits fed low levels of starch and protein in their rations significantly increased DM, OM, CP, NFE, starch and sugar digestibility coefficients and nutritive values (TDN and DCP). Neither dietary starch nor protein levels had impact on CF, neutral detergent fiber (NDF), acid detergent fiber (ADF) and EE digestibility.-There were not significant effects of starch and protein levels on dressing percentage, hot carcass weights (%), blood total protein, albumin, globulin, albumin/globulin ratio, liver activity enzymes (GOT and GPT). While, high starch level in the diet increased significantly liver weight (%) regardless of protein content.-Blood glucose, triglycerides and total protein content, amylase and protease enzymes activity in the stomach, ileum and cecum were significantly increased, while degree of pH for stomach, ileum and cecum contents was decreased by decreasing starch and protein levels in the diet. In addition, non-significant was observed in the cellulase and carboxymethylcellulase as affected by the different levels of protein and starch in all segents of the digestive tract. The results show that, total VFAs in the cecum and blood were high with 16% starch and 14% protein.-Economic efficiency and performance index were improved for rabbits fed (MS-LP) diet. However, production efficiency factor was improved for rabbits fed (LS-LP) diet. In growing rabbits, it was concluded that high correlation exists between dietary starch and protein levels which was reflected on productive performance, digestibility coefficients, digestive tract measurements and economic efficiency.

ne hundred and twenty 1-d old commercial broiler chicks (Cobb) were divided in to four groups with six replicats, to investigate the effect of dietary supplementation with organic chromium (Cr), organic selenium (Se) and Vitamin E (Vit.E) on some physiological and immunological parameters. The first group was the control group, while the second group was fed the basal diet supplemented with organic chromium (0.8 mg/kg diet), the third group was fed the basal diet supplemented with organic selenium (0.3 mg/kg diet) and the fourth group was fed the basal diet supplemented with vitamin E (200 IU/kg diet). Temperature and humidity were recorded daily and the Temperature-Humidity Index (THI) was calculated, which demonstrated that birds were exposed to heat stress throughout the experiment period. The results showed that increasing dietary levels of organic chromium, organic selenium and Vitamin E especially Vitamin E supplementation could improve plasma total protein and globulin (p<0.05) values at 42 DOA. Supplements could significantly (p<0.05) enhance the total antibody titer against Newcastle disease Virus (NDV) either for the primary or secondary response and induce higher expression of heat shock protein 70 (HSP 70). Insulin-like Growth factor-I (IGF-I) level was improved significantly (p<0.05) due to increasing dietary organic chromium levels followed by vitamin E than organic selenium. It could be concluded that the dietary addition of organic chromium (Cr), organic selenium (Se) and Vitamin E (Vit.E) triggered improvements in the physiological and immunological measurements of broilers reared under heat stress conditions

n experiment was conducted to investigate the effects of increasing dietary levels of organic chromium, organic selenium and vitamin E for deleterious impacts of heat stress on broilers. A total of 120 1-d old commercial broiler chicks (Cobb) were obtained from a local hatchary. Upon arrival the chicks were divided into four groups with six replications, each of five chicks. The first group was the control group, while the second group was fed the basal diet supplemented with organic chromium (0.8 mg/kg diet), the third group was fed the basal diet supplemented with organic selenium (0.3 mg/kg diet) and the fourth group was fed the basal diet supplemented with vitamin E (200 IU/kg diet).Body weight (BW); body weight gain (BWG); feed intake (FI) and feed conversion ratio (FC) were significantly (P≤0.05) improved in treatment groups compared to the control at 21 and 42 days of the age. Red blood cell count (RBSc), hematocrit (HT), hemoglobin (Hb), hemoglobin mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), hemoglobin mean corpuscular volume (MCV) and heterophils lymphocytes ratios (H/l ratio) were significantly (P≤0.05) different in vitamin E; organic selenium and organic chromium compared to the control at 21 and 42 days of the age, but RBSc count at 21 days of age were not significant. Moreover, it has been noticed a significant (P≤0.05) increase occurrence in values of glutathione peroxidase (GPX), Super-oxide dismotase (SOD) and catalase (CAT) but the level of malondiadehyde (MDA) was significantly (P≤0.05) decreased by supplementing broiler diets with vitamin E; organic selenium and organic chromium, respectively compared to the control. Supplementing broiler diets with vitamin E; organic selenium and organic chromium improved (P≤0.05) the carcass characteristics, respectively compared to the control. However, these improvements were insignificant in abdominal fats, thymus, bersa and spleen. The present results indicate that the supplementation of diets with vitamin E; organic selenium and organic chromium, especially vitamin E, is necessary to overcome the deleterious effects of heat stress on broilers.

he present study was carried out at the experiment farm of faculty of agriculture, Ain Shams University. The aim of this experiment was to evaluate the effect of inclusion of guar meal (G) as a partial or total replacement for soybean meal (SM) in broiler diet on production performance and carcass traits of Ross broiler chickens. At 7 days of age, 125 unsexed broiler chicks (Ross 500) were divided into 5 treatments (25 birds each). Each treatment contained 5 replicates of 5 chicks each. The experimental treatments were: control diet (100% soybean meal, SM), T1 (87.5% SM+12.5% G), T2 (75%SM+25%G), T3 (50% SM+50% G) and T4 (100% G). Results obtained could be summarized as follows: 1-Replacement SM with G in broiler chick diets had a significant effect on live body weight gain, feed intake and feed conversion ratio. 2-Chicks fed 100% G diets gave the lowest results in live body weight gain, feed consumption and feed conversion ratio. 3-Replacement SM with G in broiler chicks gave significant effect regarding slaughter parameters, carcass parts (%), digestive tract length (cm/100g BW), some bone traits and some blood parameters. 4-Broiler chicks fed diets containing different levels of G gave the lowest economic and relative efficiency values when compared with the control. Generally, using guar meal as a replacement for soybean meal at the tested levels in this study may not be beneficial under practical conditions and further research is needed to determine a more accurate level of inclusion of guar meal for better performance and carcass characteristics.

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