b. dastar

Genistein (GEN), a soybean isoflavone, is structurally and functionally similar to endogenous estrogen; therefore, it has the potential to enhance estradiol properties. This study aimed to evaluate the effects of GEN on the reproductive performance and bone status of laying hens. In total, 80 Hy-line W-36 (40 weeks old, the late stage of egg production cycle) with an initial body weight of 1,230±15.8 g (Mean±S.E.M), similar egg production, and egg weight were randomly assigned into two groups with 10 replicates and 4 birds in each replicate (40 laying hens per group). Laying hen diets had 0 (control) and 20 mg/kg GEN (white powder, Sichuan Guanghan co. Ltd., purity of 98.5%) for 6 weeks (41 to 46). At the end of the experiment, 20 hens (one hen from each replicate) were slaughtered, and the samples of bone and shell gland (approximately 50 mg) were surgically taken immediately after slaughter for Real-time PCR. The results indicated that dietary GEN increased egg production, feed intake, and egg mass; however, it decreased egg weight (p <0.05). Furthermore, the feed conversion ratio was greater in birds received GEN, compared to those in the control group (p <0.05). GEN enhanced egg quality indices included eggshell strength, thickness, and percentage (p <0.05). Mechanical properties of the tibia, such as weight, length, and breaking strength were also increased by GEN (p <0.05). Moreover, dietary GEN increased the calcium content of the tibia (p <0.05). The mRNA expression of Calbindin-D28k (CaBP-D28k) and transient receptor potential vanilloid channel type 6 (TRPV6) upregulated in eggshell glands of hens treated with GEN paralleled to the controls (p <0.05). In conclusion, the findings of the present study showed that GEN had the potential to improve the bone physical characteristics, mineralization, and the productive performance of Hy-line W-36 laying hens in their post-peak period.

Nowadays, acceptance of chicken meat as a healthy cheap meat resulted in massive consumption between consumers; consequently, higher production with higher quality and shelf life is of the main future goals of this industry (Morrissey et al. 1994). Poultry products and processing technology have become widely available and used worldwide, which leads to expanding competition in the meat production sector. Thus, success in poultry production is strongly associated with improvement in carcass growth and yield. It is mainly associated with an increase in the proportion of breast meat and a decrease in abdominal fat. While, high poly-unsaturated fatty acid content of the meat, make chicken meat prone to deteriorate during storage. So, any suggestion to achieve the industry targets including better growth performance, higher immunity condition, efficient gut function and higher meat quality is valuable. Antioxidants and antimicrobial agents are of feed additives for broiler diets that can enhance bird health and consequently can enhance food safety and quality (Cherian et al. 2013). But, because of international limitations on most antibiotic feed additives and global consumer concerns on the use of such additives, the poultry industry is looking for new alternatives with antimicrobial activities (Cherian et al. 2013). Efficacious, environmentally friendly and consumer favorable feed additives are necessary to poultry meat production. Many researches have been started on these alternatives and some of these alternatives include ionophores, prebiotics, synbiotics, acidifiers, organic acids, and nowadays medicinal plants and phytogenic. Recently, herbs or plant extracts with antioxidant capacity have received much attention. Also, the global demand for natural products from the poultry industry is rising. So, the industry has faced with popularity of using plant-based feed additives or phytogenics. Natural antioxidant compounds exist in these feed additives, can enhance lipid oxidative stability that results in better meat quality features (Aziza et al. 2010). Artemisia annua from the Asteraceae family is an annual weedy herb with global distribution originated.  The herb is native to Asia and especially known as Qinghao in China, and now has become extensively distributed all over the world. The dried leaves of A. annua have been used in traditional medicine for treating malaria-infected patients (Torabi Goodarzi et al. 2006). Anticoccidial and antiparasitic effects of the Asteraceae family have been approved in poultry and ruminant nutrition, respectively (Brisibe et al. 2008). A sesquiterpene lactone called artemisinin is the main compound representing the antiparasitic effects of A. annua and contains an endoperoxide bridge. Besides, further 40 different bioactive compounds including, flavonoids, phenolics, purines, lipids, and other aliphatic compounds exist in A.annua leaves (Brisibe et al. 2009; Ferreira and Janick. 1994). So, the purpose of this study was to investigate the nutritional effects of different levels of Artemisia annua on performance, carcass composition and oxidative stability of Japanese quail meat.

The research was conducted in the teaching and research farm of Gorgan University of Agricultural Sciences and Natural Resources, Faculty of Animal Sciences. The Artemisia annua plant was collected from around Gorgan in the late October and early November of 2018. The leaves of the plant were carefully separated and then, placed in a desiccator at 70 ° C for 48 hours. The dried leaves were powdered by electric grinding and kept in nylon in a closed package. A portion of the leaf powder was sent to the laboratory for analysis of its elements. To determine the effect of Artemisia annua on performance, carcass characteristics and oxidative stability of Japanese quail meat, a total of 375 Japanese quails were allocated in a completely randomized design with 5 treatments and 5 replicates (with 15 birds per each replicate). Birds were fed with zero, 0.5, 1, 1.5, and 2% Artemisia annua diet for 42 days. Diets were based on corn and soybean and were adjusted according to Poultry Nutrition Requirement Tables (NRC, 1994) using the UFFDA dietary software. In this study, growth performance (including weight gain, feed intake and feed conversion ratio) was calculated weekly. For this purpose, the feed intake was measured by subtracting the amount of feed left at the end of each week from the initial feed amount. Also, the mean birds weight of each replicate was subtracted from the mean weight at the beginning of the week and divided by the number of birds in that treatment in order to measure weekly weight gain. The feed conversion ratio was calculated by dividing the weight gain by feed intake. At 42 days of age, two birds were slaughtered from each pen to determine the carcass characteristics percentage (edible carcass, breast, thigh, liver and heart) and the malondialdehyde level in the breast and thigh tissues. Malondialdehyde was evaluated by the TBA method. All data were analyzed based on a completely randomized design by the GLM procedure of SAS (9.2). Tukey multiple range test was used to study the differences between treatment means.

Weight gain was not affected by dietary treatments. Supplementing 2% of Artemisia annua in the quail’s diet resulted in a significant decrease in feed intake during the last two weeks of production period (P<0.05). Gholamrezaie Sani et al., (2013) reported that broilers that received a diet containing Artemisia annua leaf powder had less feed intake compared to the control treatment they linked the reduced feed intake to the high fiber of Artemisia annua. Feed conversion ratio was not affected by dietary treatments, too. Cherian et al. (2013) reported that quails that received diets containing 2 and 4 g/kg Artemisia annua had no significant difference in final body weight and weight gain with the control group. Also, Khalaji et al. (2011) reported that diets containing 1% Artemisia annua had no effect on final body weight and weight gain.  Live weight as well as the weight of the breast, liver and heart were not different between treatments. The highest and the lowest carcass weight were observed in control and 2% Artemisia annua treatments, respectively (P<0.05). Malondialdehyde concentration in treatments containing 1.5% and 2% Artemisia were significantly different from other treatments (P<0.05). According to the results of malondialdehyde concentration in thigh muscles, a significant difference between treatments was seen (P<0.05). The highest level of malondialdehyde concentration in the thigh muscles was observed in chickens received control diet (0.769 mg / kg) and the lowest level (0.556 mg / kg) was seen in quails supplemented with 1.5% Artemisia annua. Also, the highest concentration of malondialdehyde in breast muscles was observed in the control treatment (0.961 mg / kg); while, the lowest level of malondialdehyde was seen in the breast muscles of chicks consumed diet containing 2% of Artemisia (0.638 mg / kg).

The results showed that feeding 2%of Artemisia annua in Japanese quail could increase their performance through reducing abdominal fat and increasing their meat quality by delaying in MDA production in thigh and breast muscles.

Chitin is the most abundant natural biopolymer that can be converted to chitosan, which has various biomedical applications. This study was conducted to investigate the antioxidant activity of chitosan extracted from shrimp shells on body weight of broiler chickens. The study comprised three experiments. In experiment 1, shrimp (Penaeus merguiensis) shells were demineralized using HCL (1N), deproteinized using NaOH (1N), decolorized using acetone, and deacetylated using 50% NaOH. The antioxidant potencies of chitosan and vitamin C were compared by their abilities to scavenge 1, 1-diphenyl-2- picrylhydrazyl (DPPH) free radicals. The DPPH free radical scavenging activity of chitosan at varying concentrations (1-20 mg/ml) ranged between 34.59 and 87.11%, whereas that of 1 mg/ml of vitamin C was 91.1%. In experiment 2, six dietary treatments containing varying concentrations of chitosan (0, 0.125, 0. 25, 0.5, 1, and 2 g/kg) were allocated randomly to 60 male broiler chicks from 10 to 42 days of age. Chitosan at varying concentrations had no significant effect on the body weight, but it significantly decreased the MDA level in breast meat (p<0.05). In experiment 3, a total of 20 male broiler chickens were divided into two groups (n=10) and were fed a corn-soybean basal diet with or without chitosan for 42 days. On days 35 and 38, five chickens from each group were treated with carbon tetrachloride (CCL4) at 1 mL/kg body weight to induce oxidative stress. Administration of CCL4 significantly decreased body weight and increased AST and ALT activities, which are indicators of liver damage, on day 42, whereas chitosan improved and normalized body weight and enzyme activity (p<0.05). The results suggested that chitosan extracted from shrimp shells exhibits antioxidant effects by increasing the shelf life of the meat and normalizing the body weight of the broilers as well as serum AST and ALT enzyme activities.

Bird eggs should have high internal and external quality to maintain the economic life of the product and hence recognizing and understanding thefactors affecting egg quality have great importance. In this experiment, 18 healthy eggs were selected and then exposed to a 1.5 Tesla magnetic field. After this stage, 6 samples of them were immersed in sunflower oil and stored for two days. In the next step, length and width, failure force, thickness and weight of eggshell were measured. Then, the amount of shell density, volume spherical coefficient, and egg shape index were obtained using the desired formulas. Due to the effect of the calculated parameters on the failure force of eggshells, and in order to remove this effect, the calculated failure force was divided on the calculated parameter. The results of experiment showed that the highest ratio of failure force of eggshell on the parameters was related to the samples placed in the magnetic field and no immersed with sunflower oil. As in all cases was significantly different from control samples. The lowest amount was also attributed to control samples. In general, it was concluded that the presence of samples in the magnetic field increases the shell's resistance to failure, but samples that are immersed in sunflower oil had a lower failure force than those which are not immersed in sunflower oil. Finally, it can be concluded that with the presence of eggs in a high-power magnetic field, we can see an increase in the resistance force to the shell failure.

This experiment was conducted in order to compare the effect of feed form (pellet vs. mash), dietary nutrient density and metabolizable energy (min vs. max requirement) on performance of broiler chicks. For this purpose, growth response of eight hundred Ross 308 male broiler chicks was evaluated in a completely randomized design with a factorial 2×2 arrangement (2 factors including pelleted form and dietary nutrient density each at two levels), and eight replicates for each treatment. A number of 25 birds were allocated to each treatment. Results of this experiment showed that high level of nutrient and metabolizable energy density and also feed pelleting significantly increased weight gain (P<0.05). Feed dietary nutrient and metabolizable energy density affected feed intake in the first and third week of ages (P<0.05). Increasing of dietary nutrient density did not affect feed conversion ratio, but pelleted form of feed significantly improved feed conversion ratio during whole period of experiment (P<0.05). Birds fed with pelleted diet had higher mortality than those fed with mash diet. Dietary nutrient density had no effect on meat yield cost, but pelleted of feed resulted in decrease of meat yield cost. The result of experiment showed that feeding birds with pelleted diet and high level of nutrient and metabolizable energy would improve performance of broiler chickens.

This experiment was conducted to investigate the effect of different levels of whole wheat feeding on the performance and blood parameters of Ross 308 strain broiler chickens. Birds were fed in the first week of age with a corn-soy diet and after 7 days unitl the end of the trial were fed with one of the 4 dietary treatments.The treatments were: treatment 1 (diet consist of 25 and 50% wheat flour at 7-21st and 21-42nd days of age, respectively), treatment 2 (diet consist of 5, 10 and 15% whole wheat at 21-28th, 28-35th and 35-42nd days of age, respectively), treatment 3 (diet consist of 5, 10, 15 and 20 and 25% whole wheat at 7-14th, 14-21st, 21-28th, 28-35th and 35-42nd days of age, respectively) and treatment 4 (diet consist of 10, 15, 20 and 25 and 30% whole wheat at 7-14th, 14-21st, 21-28th, 28-35th and 35-42nd days of age, respectively). Each of dietary treatments were fed to 5 replicate groups of 18 mixed sex chicks. Resultant data was analyzed in a completely randomized design. The results of this experiment indicated that whole wheat feeding had no significant effect on weight gains, feed intake, feed conversion and carcass characteristics (P>0.05). Birds were fed by control diet had significant difference with those were fed 30% whole feed for feed intake during 14-21 days of age and also birds were fed control diet had significant difference with those fed by 25% whole feed for weight gain during 7-14 days of age (P<0.05).Whole wheat inclusion had significant effect on cholesterol and glocuse concentration of blood plasma (P<0.05).

‏ This experiment was conducted to determine the performance and intestinal microflora population of broiler chicks in diets supplemented with Roxarsone, Avilamycin and Formycin gold during starter period. A basal diet was formulated according to NRC (1994) recommendation for starter (0-21 d) period and also supplemented with appropriate amounts of the mentioned growth promoters. Each of the treatment was fed to 5 replicates of 18 Ross 308 male broilers. The birds were raised on pen floor for 21 days. The microflora population in crop and ileum parts was measured on appropriate bacteriological media. Results of experiment indicated that supplementation of Roxarsone and Avilamycin, especially their combination to broiler diets, significantly improved body weigh gain of birds (P<0.05). Feed consumption and feed conversion ratios were not affected by any of the mentioned growth promoters. Adding all the growth promoters to the basal diet, except for the treatment of 0.05 percent Formycin gold, decreased total bacterial numbers in crop and ileum parts. Broilers fed diets containing Roxarsone plus Avilamycin had the lowest total bacterial population and were significantly different from those fed the basal diet (P<0.05). Supplementing broiler diets with all the growth promoters increased lactic acid bacteria population in crop, and decreased coliforms population in ileum parts. Lactic acid bacteria population was the highest in broilers fed Roxarsone plus Avilamycin and coliforms population was the lowest in birds fed 0.2 percent Formycin gold, being significantly different from basal diet (P<0.05).

This experiment was conducted to compare the effect of probiotic thepax® in diets with different quantities of protein on the performance of Cobb-500 broiler chickens and their serum antibody level against Newcastle disease vaccine (NDV). Two basal diets were formulated based on NRC (1994) recommendations which had NRC (sufficient protein diet) and 90% NRC (low protein diet) for protein. The basal diets were then supplemented with 0 and 0.1% probiotic, resulting in a 2×2 factorial arrangement with 2 levels of probiotic (0 and 0.1%) and 2 levels of protein (NRC and 90% NRC). Each of the 4 dietary treatments was fed to six replicate groups of 20 chicks. The results of experiment showed broilers fed low protein diet without supplementation of probiotic had lower performance than other treatments. Supplementing low protein diet with 0.1% probiotic significantly improved body weight gain and feed conversion ratio, as did those which were fed diets with sufficient quantities of protein. Reducing dietary protein level increased abdominal fat content, but had no significant effect on other carcass composition. Supplementing of probiotic significantly reduced abdominal fat percentage (P<0.05). The utilization of probiotic in low protein diet resulted in increasing serum antibody level against NDV, but sufficient protein diet produced no such effect. Also, the results of experiment indicated that probiotic added to low protein diet improved broilers performance and immune response. However, these effects were not observed in adding probiotic to diet with sufficient quantity of protein.

The effect of dietary protein level and feed restriction on performance, body temperature and hematological values was evaluated, using Ross 308 broiler chicks under heat stress. For this purpose, three dietary treatments were fed to broilers during 21 to 42 days of age. Two treatments consisted of diets with protein levels recommended by NRC, 1994 and 85% of NRC recommendation and were fed ad-lib during the experiment. The third treatment was a feed restriction group that was fed diet with protein level recommended by NRC, but chicks were deprived of feed for 6 hours during heat stress challenge. Birds had free access to water. Results indicated that lowering protein content or feed restriction had no significant effect on body weight gain (P>0.05). Feed restriction resulted in significantly decreased feed intake, improved feed conversion and energy efficiency ratio, and decreased body temperature after heat stress challenge at 24 and 32 days (P<0.05). Lowering protein of diet and feed restriction resulted in significantly decreased protein intake, improved protein efficiency ratio and increased hematocrit and blood uric acid (P<0.05). Sex had no significant effect on body temperature and hematological values (P>0.05). Heat stress significantly increased body temperature, hematocrit and glucose and uric acid values.

Digestible lysine and sulfur amino acid (SAA) requirements of Ross male broilers were determined during the starter period in two experiments. Broilers were fed a control corn-soy diet (3200 kcal MEn/kg and 23% CP) for 6 days and then randomly assigned to dietary treatments until 16 days of age. The basal diet containing 19% CP was prepared in order to be deficient in lysine for experiment 1 and SAA for experiment 2. Seven graded increment levels of L-lysine HCl or Dl-methionine were added in absences of starch in experiment 1 and 2, respectively. All diets contained 3200 kcal MEn/kg and all essential amino acids, except for the test amino acid, were 10% higher than the NRC (1991) recommendations. The digestible lysine requirements of broilers based on broken-line and exponential models were 1.04 and 1.01%, respectively. The digestible SAA requirements for the mentioned models were 0.846 and 0.841%, respectively.