No abstract

The present study was carried out to investigate the effect of using graded levels of Bio-Nutra 200 and Natuzyme with plant protein diets on the performance of broiler chicks. three dietary levels (0.25, 0.50 and 0.75g/kg) of either Bio-Nutra 200 (probiotic) or Natuzyme (enzyme preparation) in addition to the control without supplementation were used. Therefore, seven experimental diets were formulated to have similar crude protein and metabolizable energy contents during both starter and grower periods. Three hundred thirty six one-day-old unsexed Hubbard broilers were randomly distributed to seven equal experimental groups. The chicks were fed the experimental starter diets from one day to 21 days of age and switched to feeding the experimental grower diets from 22 to 42 days of age. All chicks were managed similarly and had free access to feed and water during both the starter and grower periods. The criteria of response were live body weight, weight gain, feed intake, feed conversion, economical efficiency of growth, carcass traits, nutrient digestibility [dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), crude fiber (CF) and nitrogen-free extract (NFE), and ash retention], some blood plasma parameters [total protein, albumin and cholesterol , and activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in blood plasma]. The obtained results for the whole experimental period could be summarized as follows: Birds fed either the probiotics-or enzymes-supplemented diets had significantly higher means of final live body weight, weight gain, feed conversion, economic efficiency of growth, nutrient digestibility (i.e. DM, OM and CF), with insignificant differences among them, compared with their control counterparts. In general, birds fed either probiotics-or enzymes supplemented diets achieved significantly higher means of most carcass traits and some blood parameters compared with birds fed control diets; however, AST and ALT were negatively affected. The other criteria were not affected by level of both feed additives. In conclusion, the current study may indicate beneficial effects of adding probiotics and exogenous enzymes (particularly with the level of 0.075 g/ kg) to broiler diets.

The current research was completed to examine the impacts of dietary enrichment with zinc oxide and stocking density on performance, plasma concentration of thyroid hormones, corticosterone(cort) and immune response and antioxidant status in cobb 500 chicks. Experimental treatments were ordered in a 4× 2 factorial plan structure with 4 degrees of included dietary zinc oxide and 2 degrees of stocking density (11.90 chicks/m 2 , normal stocking density, or 16.66 chicks/m 2 , high stocking density,). Zinc levels were 0.0, 40, 60 and 80 mg/kg diet. Elevated level of zinc (80mg/kg diet) positively affected FCR while LBW, BWG and feed intake were slightly improved compared with the control one. Additionally, Blood plasma concentricity of "total protein (TP), albumin (Alb), total lipids (TL), cholesterol (Chol), high density lipoprotein cholesterol (HDL) and low-density lipoprotein cholesterol (LDL)" did differed significantly between the control and zinc-enhanced groups. Moreover, zinc oxide enhancement in the diet could improve thyroid hormones. Also, plasma Cort levels were significantly inferior at zinc-enhanced groups as contrasted with the control one. Moreover, enhancing zinc had a huge constructive outcome on SOD, MDA and immune response titers against NDV and AFV. The typical stocking density has better effects on performance and plasma levels of Cort, TP, TL, MDA and NDV to those of the high stocking density. Stocking density did not influence "T3, T4, Alb, Chol, LDL, HDL". The results of the present examination show that enhancing zinc oxide to broiler diets has a beneficial effect on productivity, blood parameters and immunity in cob 500 chicks.

The present study was undertaken to determine the effects of feeding diets containing high nutrient concentrations on laying performance and egg quality of Bovans White laying hens during the summer season in Egypt. Two hundred hens were randomly distributed into five equal experimental groups, each composed of five replications. Hens were maintained at community cages (8 birds/cage) and subjected to similar hygienic and managerial conditions. A corn-soybean meal-based diet, containing 17.40% crude protein, 2880 kcal/kg of metabolizable energy, 4.35% calcium, 0.43% nonphytate phosphorus, 0.84% lysine, 0.41% methionine, and 0.70% methionine plus cysteine, was formulated in mash form and used as a control. The concentration of nutrients was increased to be 102.5, 105, 107.5 and 110% of those present in the control diet through some dietary manipulations, thus five mash experimental diets were formulated and fed to hens. The laying performance was evaluated in terms of egg production rate, egg weight, daily egg mass, daily feed intake and feed conversion ratio during three 28-day periods, from 44 to 56 weeks of age. An egg quality test was also performed to determine the effects of feeding the high-nutrient-density diets on egg components and some exterior and interior parameters of egg quality at the last week of study. At the first 4-week period, feeding the high-nutrient-density diets had no significant effect on laying performance of hens but daily feed intake was inconsistently affected. At the second period, hens fed high-nutrient-density diets achieved significantly higher egg production rate (EPR) and daily egg mass (DEM) compared with the control group while egg weight (EW), daily feed intake and feed conversion ratio (FCR) were not affected. At the third period, hens fed 105 and 107.5% diets consumed significantly more feed and displayed higher EPR and DEM than those of other dietary treatments but EW and FCR were not affected. Feeding the high nutrient density diets produced significant improvements in egg weight, yolk index and Haugh units compared with their control counterparts while percentages of egg components, shell weight per unit surface area (SWUSA), egg shape index and yolk color score were not affected. It is concluded that increasing dietary nutrient density up to 110% of the recommended requirements of Bovans White laying hens can positively affect some egg quality traits but had inconsistent effect on their productive performance under Egyptian summer conditions.

The aimof this study was to assess the effect of in ovo injection with saline, vitamins (D3 and B12) and zinc and L-carnitine on the hatching rate and blood constituents in newly hatched chicks. A total of 1170 eggs from broiler breeders were divided into sixtreatmentgroupsof eggs:a control group without injectionwhich served as sham-operatedor a negative control group and five groups were injected with saline, vitamin D3, zinc, vitamin B12or L-carnitine, respectively. All eggs were set at a temperaturerange between 24-26°C for 6 hours before exposure to the incubation temperature. Then the injection process occurred at the 18 th day and 12 hours of the embryonicdevelopment by depositing the test materials into the air sac at the wide end of the eggs, then the hole was closed with wax. The highest value of fertile hatchability was recorded in eggs injected with vitamin D3 and zinc, respectively, followed by vitamin B12 and L-carnitine. The injected test materials (vitamin D3, zinc, vitamin B12and L-carnitine) had a positive effect on the percentage of late dead embryos compared to negative control group. All injected materials except zinc led to an increase in plasma levels of cholesterol and low-density lipoprotein but levels of glucose, triglyceride, high-density lipoprotein, total protein, albumin and globulin were not affected. In conclusion, in ovo injection of vitamins (D3 and B12), zincand L-carnitine may be suggested as an effective technique for increasing hatchabilityand profitability in aged broiler breeders.