The aim of this study was to evaluate the effect of adding protease enzyme to low protein corn-soybean meal broiler diets to reduce feeding cost and improve the quality of meat. Two hundred and forty 1-d old unsexed Arbor Acres broiler chicks were distributed to six treatments (2*3 factorial design) of 4 replicates each. Two levels of protease activity (without and with 300 000 U/kg of the diet), and three levels of dietary crude protein were examined (Standard, STD; less 10% or less 15% from STD protein recommendation of each feeding phase, L10 and L15, respectively). The dietary protein levels were 23, 20.7and 19.5% at the starter phase; 21, 18.9 and 17.8% at the grower phase; and 19, 17.1 and 16.1% at the finisher phase. Diets were formulated to save the strain requirements of all other nutrients. All chicks were housed in open system broiler house and received the same managerial conditions and veterinary program during experimental period (1-40 d of age). Parameters of growth performance, carcass characteristics, physical and chemical evaluation of broiler meat were carried out and feeding cost was calculated. The recorded results showed that using protease improved final body weight (4.1%) and feed conversion ratio (6.1%) and reduced skin% of drum stick significantly (P<0.05). Decreasing protein of diets to (L15) increased consumed feed, drip loss of thigh, and back quarter weight (thigh and drumstick). Also, skin and pH of breast and concentrations of low density lipoprotein and malondialdhyde (MDA) in broiler meat were depressed significantly (p<0.0001). Among all treatments results showed that adding protease to L10 diets recorded the same marketing weight (2015 g), made broiler meat healthier (MDA decreased by 36%), and depressed the feeding cost/kg of life body weight by 3.94% relative to value calculated for STD group. Generally it could be concluded that adding 300,000 U protease enzyme/kg to low protein broiler diets could help producers to achieve acceptable marketing weight, get better meat quality, and reduce feeding cost according to Egyptian prices of feed ingredients.

The present studywas designed to evaluate the influence of supplementing different levels of L-Valine (L-Val) to low protein diet on chicks' performance, carcass characteristics , digestibility of nutrients andeconomical efficiency. A total number of 640 unsexed day old Arbor Acres meat-type chickswere assigned randomly into 8 equal treatments containing 80 chicks each (10 birds/ replicate). The first group (control) was fed strain recommendation of CP being 23%, 21% and 19% with 0.96, 0.88 and 0.79% digestible valine during starter, grower and finisher periods, respectively (T1). The 2 nd group was feddiets with a 3% CPless thanthe control, being 20%, 18% and 16% and contained 0.89, 0.79 and 0.69% digestible valine level during the same growth phasesrespectively, as control (T2). Other six groups were fed low-CP diet (LPD) supplemented with 250mg, 500mg, 750mg, 1000 mg, 1250 mg and 1500 mgL-Val/kg diet, respectively. The study lasted for 38 days. The results were as follows:1-The best BWG and FCR during overall growth period was achieved by chicks fed the LPD supplemented with 500 mg Val/kg diet, and control group (T1) without significant differences between them.2-Valine digestibility was ranged between 91.17 to 97.03%.3-Control group achieved significantly the lowest abdominal fat percentage as compared to the other groups fed LPD either with or without valine supplementation.4-Chicks fed the LPD plus 500 mg Val/kg diet attained the highest means of economic efficiency and its relative value by 103.2% and 114.2% as compared to those fed the recommended protein diet and LPD, respectively. In conclusion, the best level of added Val is 500 mg/kg diet for broilers fed LPDsupplemented with sufficient amount of Methionine, Lysine, Threonine which coincided with the best Val/Lys ratio during starter, grower and finisher periods. Also, it achieved an improvement in economic efficiency and growth performance of broilers.

his experiment was conducted to study the ability of supplemental xylanase enzyme (Xyl) to improve growth performance, carcass traits, meat quality and feeding cost of broilers fed on low metabolizable energy (ME) corn-soybean meal diets. Two hundred and forty, one day old unsexed Arbor Acres broiler chicks were randomly distributed into six treatments (2x3 factorial design) each had four replicates. Chicks were fed on corn-soybean diet supplemented with two levels of Xyl (0 and16000 U/kg of diet), and three ME levels which were standard strain recommendation (STD), 100 kcal lower than STD (E100) and 150 kcal lower than STD (E150) of each feeding phase for STD, E100, and E150 levels, respectively. The dietary ME values were 3000, 2900 and 2850 kcal/kg diet at starter phase; 3100, 3000 and 2950 kcal /kg at grower phase; and 3200, 3100 and 3050 kcal/kg at the finisher phase. All diets were formulated to save the strain requirements from the rest of nutrients. All chicks were housed in open system broiler house and received the same managerial conditions and veterinary program during experimental period (1-40 d of age). Parameters of growth performance, carcass characteristics, physical and chemical evaluation of broiler meat were carried out and feeding cost was calculated. The recorded results showed that xylanase supplementation to broiler diets resulted in significant improvement of body weight, body weight gain, feed conversion ratio, dressing %, and breast meat yield %, while feed intake and ultimate pH (pHu) of both breast and thigh cuts were decreased. Regarding to ME of diets, reducing ME values from STD level to E150 level caused significant reduction in final body weight, abdominal fat %, pHu of breast meat samples and concentrations of malondialdehyde (MDA) and low density lipoprotein (LDL). Furthermore this reduction of ME levels caused significant increase of feed intake, % of drum stick and concentration of total protein of broiler meat at 40 d of age. Among experimental treatments chicks of both STD+Xyl and E100+Xyl treatments showed better growth performance, carcass traits, and meat quality compared with other treatments. In addition applying these treatments resulted in saving 9.25 % and 3.51% from feeding cost/kg of body weight relative to feeding cost of STD group. According to these results it could be concluded that adding xylanase enzyme to either STD or E100 corn-soybean meal broiler diets could enhance the quality of produced broiler accompanied with saving in feeding cost.

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This study aimed to investigate the effect of natural antioxidants sources on laying performances, egg quality and economic efficiency compared with dietary vitamin E supplementation during summer season. Two hundred and seventy 20 week old Babcock Brown that reached 40% egg production were distributed randomly into 9 treatments. Each treatment contained 30 birds in 6 replicates. The first treatment performed control treatment and treatments 2, 3, 4 and 5 fed diets contain Vitamin E (E) 100 mg/ kg diet, Green Tea extract (G) 4ml/kg diet, Tomatoes Puree (T) 5g/kg and Canthaxanthin (C) 4mg/kg diet respectively. Treatments 6, 7 ,8 and 9 fed diets contain G+T, G+ C, T+C and G+T+C, respectively. The overall results showed that, significant enhancer effect of all experimental treatments on average feed conversion, egg numbers, weight, math and yolk color score more than control groups. The combination between more than antioxidant source resulted in better values of egg production, egg quality and yolk analysis, the highest combination were triple mixture G+T+C and double mixture T+C. The group fed T+C showed the highest values of albumen height, yolk color, and yolk index. All supplementation treatments significant decreased yolk triglycerides (TG) and significant increased yolk Total Antioxidant Capacity (TAOC) compared with control. Single, double and triple supplementation improved egg production, egg quality, TG, TAOC and economic efficiency. Also, T + C and G +T + C were the best among all parameters and could be used as VitE as natural antioxidant sources for laying hens through summer season.