جستجوی مقالات مرتبط با کلیدواژه « مرغ های تخم گذار » در نشریات گروه « علوم دام »

Humate material was used as feed additives in poultry nutrition. The biochar as a useful fertilizer in agriculture industry is a humate material that increases growth of plants. This fertilizer can as an additive be use in the poultry and animals feed, due to has many minerals material and two organic acid (humic and fulvic) in its compound. The reduce cost of diet in poultry industry for egg production, is an important goal. The biochar as a dietary additive is easily derived from burn organic material and agriculture byproduct. In recent years, several studies have been conducted to determine the effect of humic acid as an additive on performance poultry. In a study, dietary supplementation of laying hens with humic acid improves the performance and egg shape index. Investigating the effect of biochar as replacement of dietary mineral supplements on performance and egg shell quality of laying hens is rare. One of the properties of vitamin C (VC) is chelating properties, and with this property, it increases the intestinal absorption of minerals in birds. Therefore, this study was conducted to investigate the effects of biochar (as a humate material) in five levels and vitamin C in two levels as replacement of dietary mineral supplements on performance and egg shell quality of laying hens.                        The current experiment was conducted to evaluate the effects of biochar with vitamin C as replacement of mineral supplement in diet of laying hen. A total of 400 laying hens of Bovans strain, were randomly assigned to 10 experimental groups in a 5×2 factorial treatment arrangement with five replications and eight laying hens in each replicate during three 30-day periods. Factors tested included biochar levels (0, 25, 50, 75, and 100% replacement with mineral supplements of diet) and vitamin C levels (0 and 100 mg/kg of diet). The feed intake, feed conversion ratio and daily weight gain were determined. Records of the feed intake were taken on by daily basis. Feed conversion ratio was calculated as grams of feed consumed to grams of egg mass. To determine egg shell quality characteristics, the shape index was calculated by using egg height and egg width. The egg specific gravity was evaluated by floating eggs in soluble of water and salt with different density. The egg breaking strength was measured by resistance meter. Replacing biochar levels from 25 to 100% mineral supplement of diet, with and without vitamin C, had no effect on performance characteristics (feed intake, feed conversion ratio and daily weight gain) and egg shell quality traits (egg shape index, egg specific gravity and egg breaking strength) in total of period of the experiment (50 to 61 weeks of age). The levels of 25 and 50% biochar, plus vitamin C in diet decreased feed intake in the first period. Whereas, the level of 75% biochar, plus vitamin C in diet increased feed intake in this period. The egg shape index with the addition of vitamin C in diet decreased in the third period. The reason of no significant effect of biochar on performance and egg shell quality can be due to the different sources and amounts of biochar in poultry diet. The reason of no significant effect of vitamin C on performance and egg shell quality in laying hens can be due to the bird environmental temperature. The use of vitamin C in diet of laying hens under heat stress improves their performance. Whereas, this study was performed in normal environmental temperature. The second reason is the chelating properties of vitamin C,  that can be increased absorption minerals in birds intestinal. But due to advanced digestive tract of laying hens, maybe decrease its properties.    The results of present study showed that biochar across all levels had similar cost with control group, and it had no effect on egg shell quality and performance of laying hens. There was no significant interaction between biochar and vitamin C regrding to performance, egg shell quality traits and cost of diet during 50 to 61 weeks of age, too. Therefore, biochar can be completely replaced with dietary mineral supplements of laying hens due to its low cost, high availability, easy production without adverse effects on performance and egg quality traits.

The inclusion of prebiotics in layer hen diets can act as a growth-promoting antibiotic replacer and have beneficial effects on egg production and egg quality. This study aimed to investigate the effects of liquid prebiotic on the post-molt laying performance, egg quality at different storage temperatures and times, immune system function, and blood biochemical parameters of laying hens.

A total of 144 White Leghorn Hy-Line W-36 laying hens at 83 wk of age were randomly assigned to 6 dietary treatments, 4 replicates, and 6 birds per each for 6 weeks in a complete randomized design experiment. Experimental diets were: 1- A corn-soybean meal-based diet without adding liquid prebiotic as a control, 2 to 5- Supplementing basal diets with 0.5, 1, 1.5, 2 ml of liquid prebiotic per Kg of diet, 6- basal diet with adding 500 mg of oxytetracycline as an antibiotic per kg of diet. Laying performance including egg production, egg weight, egg mass were recorded daily, and feed intake and feed conversion ratio were calculated weekly. In order to evaluate the egg quality traits at various storage temperatures (refrigerator temperature (4ºC) and room temperature (25ºC) and storage periods (0, 7, 14 days), two eggs were randomly selected from each replicate in the 2th, 4th and 6th weeks of the experiment and the egg quality traits were measured. To evaluate the effects of liquid prebiotic supplementation on humoral immunity, antibody production against sheep red blood cells (SRBC) was used. The data were subjected to statistical analysis using a completely randomized design by SAS 9.1 software (SAS, 2004). The egg quality traits data were subjected to analysis of variance in a completely randomized design as a 6×3×2 factorial arrangements (6 levels of liquid prebiotic and antibiotic supplementations, 2 different storage temperatures and 3 storage periods).

The results showed that by increasing the prebiotic supplementation, the daily egg production (p=0.0057) and egg mass (p=0.0013) were linearly increased, and feed conversion ratio (p=0.0016) were linearly decreased. The effect of adding liquid prebiotic on egg quality traits including egg shape index, shell percentage, and shell thickness was not significant (p>0.05), but the effect of storage period on egg shape index and the effect of storage temperature on shell thickness and egg shape index was significant (p<0.05). Supplementation of diets with liquid prebiotic was significantly influenced the cholesterol, glucose, calcium, and aspartate aminotransferase (AST) concentrations of laying hens (p<0.05). The total antibody titer (IgT) against SRBC was increased by increasing supplemental prebiotic.

In conclusion, supplementation of 2 ml/kg liquid prebiotic in the diet of layer hens at post-molt period can act as an alternative to antibiotic growth promoters, thus the laying performance was enhanced, and by augmentation of production the specific immunoglobulins, the immune status was improved.

 One of the main problems in feeding native hens for optimal egg production is mineral deficiency, especially calcium sources. Calcium is present in the blood plasma and is part of the cells and tissues of the body and is essential for the activity of some enzyme systems involved in the transmission of nerve currents, muscle contractions and normal heart rate and also along with phosphorus to transfer fat to the yolk. This experiment was conducted to evaluate the effects of different levels of calcium and phosphorus on performance, immunity, characteristics of eggs, percentage of bone calcium and phosphorous and percentage of hatching in Khorasan province native hens.

A total of 200 native hens from Khorasan station were used in a completely randomized design (factorial experiment) with 4 treatments, 5 replicates. Experimental diets based on two levels of Ca (2.5 and 3.5) and total P (0.5 and 0.75) per percent of diet. The hens had free access to water and food during the experiment. Eggs were collected and weighed daily in each pen and its mean was recorded as its weight and number. At the end of the experiment, one hen was selected from each replication, slaughtered and after isolating the femur, the percentage of calcium and phosphorus was measured. Hemagglutination method was used to measure the antibody titer against SRBC. All data were analyzed using SAS software and the means were compared based on Tukey test.

The results showed that different levels and P did not show any effect on egg weight, egg production, egg mass, feed intake and FCR (P>0.05). Levels of Ca have significant effect on the egg production, so that the highest egg production, egg mass and feed intake was observed in the 3.5% Ca (P>0.05). The interaction of phosphorus and calcium significantly changed the performance indices except egg weight, and The best feed conversion ratio was observed in the group receiving 0.5% P and 3.5% Ca (P<0.05). Different levels of P did not show any effect on shell egg and thigh bone characteristics (P>0.05). Increased P had no effect on the hatchability, But calcium caused an increase 3-9 percent of hatchability during the test period (P<0.05). Increased calcium and phosphorus did not have any significant effects on immunity indexes (P<0.05).

Overall, the results of this experiment showed that the levels of 0.5% P and 3.5% Ca can be reported as levels of calcium and phosphorus requirement of laying hens native.

[1] Increasing feed costs are significant issues in the poultry industry. Therefore, poultry producers often interested to feed low energy and nutrient dense diets to reduce production cost, while low energy and nutrients dense diets may not appear to supply sufficient energy for laying hens. Hens can regulate their feed intake to maintain energy and nutrient intake in accordance with their requirements. In this way, hens will consume more of a low energy and nutrients dense diet than of a high energy and nutrients dense diet, ensuring the calories and nutrient consumed be sufficient. However, some studies have shown that hens especially the modern ones are not precise in adjusting their feed intakes, such as the Hy-Line W-36, since they only have a limited capability to increase their feed intake to ensure adequate energy and nutrients intake. While low energy and nutrient dense diets are less expensive to purchase, they may not ensure optimal egg production if hens are unable to adjust their feed intake. On the other hand, the purchase price of low energy and nutrient dense diets can be substantially lower than high-density diets, if they are effective in maintaining long-term egg production performance, so that can result in increased returns for the producer. Thus, feeding low energy and nutrient dense diets to laying hens may result to improve returns due to a lower cost of diets. However, it has been shown that the increased efficiency of birds fed on high energy and nutrient dense diets can offset the higher cost of feed. The hypothesis of this study was to investigate how Hy-Line W-36 laying hens in post molting period can respond to lower energy and nutrients dense diets, through their increase in feed intake to maintain energy and nutrient consumption to support egg production.

The birds that used for this experiment were molted at the 70wk of age on a non-fasting feeding program according to the molting recommendation by Hy-line W36 laying hens guide. Three hundred twenty 78wk Hy-Line W36 hens were individually weighed and randomly assigned to 80 cages of four birds each. Eight replicate groups of 8 hens each (two adjacent cages) were randomly assigned to each of the 5 treatment diets with location within house as blocking criteria. The pre-experimental period was two weeks for acclimatization, and the experimental period was from 92-103 weeks of age (three 28d periods; 92-95, 96-99, 100-103wk of age). Experimental diets were formulated according to the guidelines in the Hy-Line W-36 Commercial Management Guide (2015) for 104g feed intake according to the average pre-experimental period egg production and feed intake data. Thus the control diet (100% of recommendation) was formulated to contain 2845 kcal/kg AMEn; 14.42% CP; 4.14% calcium; 0.48% available phosphorus; 0.17% sodium; 0.67% digestible lysine; 0.36 digestible methionine; 0.56 digestible methionine + cysteine; and 0.47 digestible threonine. Four other dietary concentrations of energy and nutrients density were formulated to provide 91, 94, 97, and 103% and one diet with the 100% of recommendations stated in the 2015 Hy-Line W36 commercial management guide. Egg production (number and weight) and mortality were recorded daily, whereas feed consumption was measured every 4wks as feed disappearance. Six eggs/replicate (48 eggs/treatment) laid in the last 72 h of each 28d period were collected and transported to Egg Quality Laboratory at the Ferdowsi University for of egg weight, albumen, yolk and shell relative weight, Haugh units, egg shape index, egg special gravity, and shell thickness determination. The feed cost/kg egg production was calculated by feed costs time feed conversion ratio. Data were analyzed by ANOVA using the GLM procedure of SAS 9.1 (2003), with dietary treatment and block as independent variables. Diet effects were evaluated using linear and quadratic orthogonal polynomial contrasts. The linear broken-line (LBL) and quadratic-broken line (QBL) regression models were used to estimate the dietary energy and nutrient density ratios for optimization of egg mass and feed conversion ratio.

Previous research showed that hens would linearly adjust their feed intake in response to diet nutrient density by eating significantly more feed that was low in energy and less feed that was high in energy. These changes in feed intake were not in agreement with the results of the current study showed that egg production, and egg mass were increased and feed conversion ratio (FCR) decreased significantly and linearly, with the increase in dietary energy and nutrients density. There was not any significant difference in the egg production, egg mass and feed conversion ratio in birds fed diet containing three percent (103%) more nutrient density than that of strain recommendation. Whereas, feed intake, egg weight, white yolk and shell relative weight, egg shape index, specific gravity, egg shell thickness as well as Haugh unit were not significantly affected by dietary energy and nutrients density. Significant linear increase due to increase in energy and nutrients density were observed for most measured parameters, including hen-day egg production, egg weight, egg mass, feed efficiency, energy intake, and body weight gain. The hen-day egg production showed that hens fed diets containing 91% of control diet laid fewer eggs than those fed diets with 100 or 103% of nutrients recommendation. The energy and nutrient requirement for optimal egg mass (g/b/d) and FCR during the post molting period (92-103Wk) by LBL model were 94.96 and 97.02%, and by QBL model 95.71 and 95.95% of strain recommended, respectively.

In summary, the increase in energy and nutrients density in diet of Hy-Line W-36 laying hens increased egg production, egg weight, egg mass, energy intake as well as decreased body weight losses and feed conversion ratio. The regression analyses of data showed that, laying hens diet formulated at the 95-97% of nutrients recommendation had the optimal egg production and economic performance during the second egg production cycle. Furthermore, hens were unable to adjust their feed intakes since the lowest energy and nutrients density diet deteriorate egg production performance.

The current study was conducted to evaluate the effect of different levels of Zataria multiflora, Salvia officinalis, the mixture of Zataria multiflora and Salvia officinalis as well as probiotic (Protexin®) on egg quality traits, blood biochemical parameters and liver histomorphological changes in laying hens. A test was performed using 225 Leghorn laying hens, after peak of egg production (42 weeks old), for 10 weeks. The birds were randomly assigned into 9 experimental treatments with 5 replicates and 5 birds in each. Experimental treatments consisted of a control group, 0.2 and 0.4% Zataria multiflora leaf powder, 0.2 and 0.4% Salvia officinalis leaf powder, 0.2 and 0.4 the equal mixture of Zattaria multiflora and Salvia officinalis and 0.005 and 0.01% probiotic (Protexin®). Our results indicated that using 0.4% of Zataria multiflora and Salvia officinalis leaf powder mixture marginally reduced the relative weight of liver (P=0.07), decreased serum activities of SGOT (P=0.08) and SGPT (P<0.05), and also increased hepatocytes color density (P<0.05) and HDL concentration (P<0.05). Feeding 0.4% of the medicinal plants mixture increased eggshell weight, slightly (P=0.06), and enhanced eggshell hardness (P<0.05), yolk color (P<0.05), and Haugh unit, significantly (P<0.05) during the second 35-day experimental period (48-52 weeks of age). Therefore, the present findings suggest that dietary inclusion of 0.4% mixture of powdered herbs of Zattaria multiflora and Salvia officinalis can improve the liver health indices, blood lipid profile and egg quality traits, such as eggshell hardness, yolk color index, and haugh unit compared to other medicinal plants levels or probiotic, markedly.

This research was conducted to evaluate the effect of some feed additives compare to Flavomycin growth promoter antibiotic. Experiment was conducted in completely randomized design manner consisting 3 treatments, 5 replicates and 20 hens per each replicate using 300 White Leghorn, Hy-Line W-36 strain. The experimental treatments included: control, Flavomycin growth promoter antibiotic at 0.05% dietary level and feed additive mixture consisting of thyme and oregano plant extracts and propionic acid and zinc supplement at 0.1% dietary level which fed to laying hens for 42 days (3 periods of two weeks each). The results of this study showed that the utilization of feed additive mixture significantly (P

This experiment was conducted to evaluate the effect of raw and/or autoclaved grass pea (Lathyrus sativus L.) seed in diet on performance and egg quality of laying hens. Three hundred and thirty-six Leghorn laying hens strain W-36 at 87 week of age were assigned in a completely randomize designed (CRD) experiment with 7 treatments, 6 replicates and 8 birds each. The experimental treatments included; corn-soybean meal (control) diet, and 8, 16 and 24% dietary levels of either raw or autoclaved grass pea grain. The experiment lasted for 12 weeks. Feed consumption, egg production percentage and egg mass of hens fed diets containing different levels of raw and autoclaved grass pea grain were significantly lower and their feed conversion ratio was significantly higher than those fed control diet. The autoclaving of grass pea grain resulted in significant increase in performance and eggshell quality indices in birds fed diets containing 16 and 24% grass pea grain. Although autoclaving of grass pea grain reduced the negative effect of its replacement in the diet on performance and egg characteristics, however, it could not compensate the reduction in performance. According to the results of this experiment, the utilization of raw grass pea grain is not recommended in laying hen diets. Also, autoclaving process alone can’t destroy the anti-nutritional factors present in grass pea grain.

This study was carried out toinvestigate the effect ofmannan-oligosaccharide prebioticonperformance,egg quality, immune response, intestine ileum microflora and nutrient digestibility in laying hens fed various levels of crude protein. A total of 150 Hy-Line W-36 layinghens were assigned to a 2×3 factorial arrangement of treatments. Experimental diets consisted of 3 levels of crude protein (recommended level for strain, 90 and 95% of recommended level) and 2 levels of mannan-oligosaccharides (0 and 0.1% of diet). Reduction of crude protein to 10% of basal diet resulted in decrease of egg weight, egg production, egg mass and feed conversion ratio (P

This experiment was conducted to evaluate the effects of different levels of diet metabolizable energy on performance, egg traits and blood parameters of aged laying hens. In this experiment 192 Hy-line (W36) laying hens were used from 65-74 weeks of age in 4 treatments, 4 replicates and 12 hens in each replicate in a completely randomized design. The amounts of ME were 2800, 2900 (control group), 3000 and 3100 kcal/kg in 1-4 experimental groups. The highest egg weight, egg percentage, egg mass, the best feed conversion, the lowest feed cost for production each kilogram of egg, the highest egg color index, albumin and yolk, Haugh unit and egg shell thickness were observed in diet contained 2900 kcal/kg ME. High level of energy in diets, reduce the amount of feed intake and egg production, Haugh unit and shell thickness. In using low ME in diet, as the amount of feed intake without egg production improve increased, the production cost increased, whereas the egg color index, eggshell percentage and Haugh unit reduced. Using different levels of diet metabolizable energy did not have any significant effects on blood biochemical parameters and immune cells of laying hens (P

This experiment was conducted to evaluate the effects of different levels of untreated and urea treated lemon pulp on performance, egg traits and blood parameters of laying hens. In this experiment 192 Hy- line W36 laying hens were used from 35-46 weeks of age in 4 treatments, 4 replicates and 12 hens in each replicate in a completely randomized design. Experimental groups included: 1) control group (without using lemon pulp), 2) group with 4% untreated lemon pulp, 3) group with lemon pulp treated with 0.5% urea, 4) group with lemon pulp treated with 1% urea. The results showed that using lemon pulp and its treating, have significant effects on performance and egg traits of laying hens (P0.05). The overall results indicated that using 4% of lemon pulp untreated and treated lemon pulp with 0.5% urea, improve the performance and egg traits of laying hens and reduce the production price

In this experiment the effects of different parts of Cichorium intybus L. on performance, egg quality traits and blood parameters of laying hens were evaluated. A total of 199 Hy-line (W36) laying hens (from 52 to 63 weeks of age) were allocated to the experimental units in a completely randomized design in 4 treatments with 4 replicates of 12 hens in each. The experimental groups included: 1) control group, 2) group with 3% aerial parts of Cichorium intybus L, 3) group with 3% root of Cichorium intybus L., 4) group with 3% whole parts of Cichorium intybus L. The results showed that use of Cichorium intybus L, had significant effects on performance, egg quality and blood cells parameters (P<0.05). The highest values of egg production (62.19%), egg mass (38.23%), feed intake (110.68 g), the best feed conversion ratio (2.89), the highest egg yolk color index (4.00), the highest Haugh unit (74.50), the lowest heterophile percentage (9.33%), the highest lymphocyte percentage (90.67%) and the lowest heterophile to laymphocyte ratio (0.104) were observed with using 3% of whole Cichorium intybus L. Using 3% whole Cichorium intybus L caused the eggshell thickness decrease to 0.33 mm. Experimental groups had no effects on blood biochemical parameters. As overall results, in laying hens using 3% whole Cichorium intybus L in contrast to control group and groups contained other parts of Cichorium intybus caused the performance, egg yolk color index, Haugh unit and blood cell immune improve.

Silybum marianum and purslane seed contains many compounds that can be useful for laying hens. This experiment was conducted to study the effect of different levels of purslane and milk thistle seed into the diet of laying hens on performance, some egg quality traits and serum and egg yolk lipids. A 3 × 3 factorial experiment with three levels of purslane seed (0, 1 and 2%) and three levels of milk thistle seed (0, 1 and 2%) in the diet in a completely randomized design with 288 laying hens Hy-Line W-36 who were reared in cages, from 32 to 42 weeks with 9 treatments, 4 replicates and 8 hens in each replicate. Supplementation of 1% purslane seed and 2% milk thistle seed on diets, significantly increased egg weight (P<0.05). Also the use of 2% purslane seed significantly increased the egg production and egg mass of laying hens (P<0.05). The best feed conversion ratio obtained in hens receiving 2% purslane and 0% milk thistle which was significant compared to the control treatment (P<0.05). Shell thickness and haugh unit significantly improved by consumption of 2% milk thistle seed (P<0.05). Different levels of purslane seed and milk thistle, reduce the cholesterol and triglyceride in blood serum and yolk, but were not significant. The levels of blood HDL of birds showed a significant increase by adding 2% purslane seed (P<0.05). The results of this study suggest that the levels of 2 percent milk thistle and purslane seeds have beneficial effects on performance factors and level of 2 percent milk thistle seed improves egg quality traits in laying hens.

This experiment was conducted to evaluate and compare antibiotic، organic acid، probiotic and prebiotic effects on performance، egg quality and blood metabolites in commercial laying hens. The experiment was a completely randomized design with 160 laying hens strain Hy line (W-36) from 32 to 42 weeks of age with 5 treatments and 4 replicates of 8 hens each. The experimental treatments consisted: 1- basal diet، 2- basal diet + 150 g/ton oxy tetracycline antibiotic، 3- basal diet + 3 kg/ton of organic acid supplementation، 4- basal diet + 50 g/ton probiotic (Protexin) and 5- basal diet + 2 kg/ton of mannan oligosaccharide prebiotic. The results showed that the use of antibiotic، organic acid، probiotic and prebiotic have significant effects on performance and egg quality traits. Accordingly، the maximum egg weight was obtained in treatments receiving organic acid and prebiotic that was significant compared to control treatment. Egg mass and feed conversion ratio in treatment received prebiotic significantly improved. The maximum egg shell weight was obtained in treatment received prebiotic that compared to the control treatment showed a significant increase. Between blood factors، glucose concentration in treatment received organic acid compared to control and antibiotic treatments، significantly increased. Consequently the use of organic acids and mannan oligosaccharides can have positive effects on performance and egg characteristics of laying hens.

This experiment was conducted to evaluate the effects of different levels of crude protein and probiotic in diets on performance, egg quality and blood biochemical and immunity parameters of laying hens. A completely randomized design with factorial method (2×4) was conducted in which two levels of crude protein (NRC and 10% lower than NRC recommendation) and 4 levels of probiotic (0,. 025%, 0.05% and 0.075%) were tested on 288 of Hy- line (W36) laying hens for 12 weeks from 42-54 weeks of hens ages. Results showed that the different levels of crude protein and probiotic in the diets have significant effects on performance, egg traits and immunity parameters of laying hens (P<0.05). Low crude protein diet significantly reduced the egg production percentage, egg mass, feed intake and increased the feed conversion ratio. Inclusion of probiotic in the diets decreased the amount of daily feed intake. Using different levels of probiotic with different levels of crude protein could not improve the performance of laying hens. The shell surface weight was decreased when the laying hens received low protein diet. Inclusion of probiotic improved the egg specific gravity, but the highest level of probiotic decreased the eggshell percentage. The blood hemoglobin percentage was positively affected by the probiotic content in the diet. Different levels of dietary crude protein, probiotic and interaction between them could not significantly changed the blood biochemical parameters

In this experiment for evaluation the effects of different levels of Rosa canina L. fruit on performance, egg traits and blood parameters, total of 288 Hy-line (W36) laying hens from 35 to 46 weeks were allocated to the experimental units in a completely randomized design in 6 treatments with 4 replicates of 12 hens each replicate. The dietary levels of Rosa canina L. fruit included in the study were: 0, 1, 2, 3, 4, and 5 % of diets. The results showed that use of Rosa canina L. fruit up to 5% in diets improved the egg production, egg quality traits and blood parameters compared to the control group (P<0.05). The best performance, the lowest feed price for each kilogram of eggs, the best egg quality traits and the lowest amount of uric acid in blood were observed with 3% of Rosa canina L. fruit. The lowest amounts of hematocrit, hemoglobin and red blood cells were seen in diet with 5% of Rosa canina L. fruit. Whereas, the lowest percentage of heterophle and the lowest ratio of heterophle/lymphocyte were observed with 2% of Rosa canina L. fruit. The overall results indicated that in laying hens, 3% of Rosa canina L. fruit in contrast with other experimental groups, significantly improve performance, egg quality traits, blood parameters and feed price for each kilogram of eggs.

This experiment was conducted to evaluate the effect of different levels of Silybum marianum seed on performance and some egg characteristics such as egg shell weight, shell thickness, yolk index, yolk color and Haugh unit of laying hens. The experiment was undertaken on hay-line strain (w-36) from 32 to 42 weeks, using a completely randomized design with three treatments, four replicates and four hens in each replicate. The experimental diets were: 1- basal diet (control), 2- basal diet + 1% Silybum marianum seed and 3- basal diet + 2% Silybum marianum seed. The results showed that through performance trait, the average egg weight in treatment having 2% Silybum marianum had a significant increase compared to the control treatment (P<0.05). Although egg production increased in treatments containing Silybum marianum, this increase was not statistically significant. Egg mass in the treatment having 2% Silybum marianum significantly increased compared to the control (P<0.05). Feed intake and feed conversion ratio decreased in the treatments containing Silybum marianum but was not statistically significant. Between egg characteristics, yolk color in the first period was significantly increased by 1% Silybum marianum (P<0.05). Also Haugh unit increased in all treatments containing Silybum marianum, but this increase was significant only in the second period (P<0.05). Based on the results obtained from this research, the use of milk thistle seeds in the diet of laying hens had beneficial effects on performance and egg characteristics such as the Haugh unit in laying hens.

This study was conducted to survey a laying parent stock performance and egg quality traits. A laying parent stock unit was selected at the age of 52 wk and data including hen and cockerel number, mortality percent, hen to cockerel ratio, egg production percent (hen day and hen housed production), non- settable egg number and settable egg (%) were recorded daily up to 72 wk of age before beginning of molting. For calculating hatchability (%), the data were obtained from hatchery unit. The collected data were divided to 6 experimental periods (28 days/period). At beginning of the study, the number of hen and cockerel were 30013 and 4144, respectively. The hen to cockerel ratio was 14. The percent of hen and cockerel mortality at experimental periods were 0.033 and 0.022, respectively. Hen day egg production (%) was lowered as compared to the recommended data in parent stock management guide (5.55 %). Generally, the analysis of the data showed that with increasing experimental periods (or the age of birds), the non-settable and settable egg numbers were increased and decreased, respectively. The settable egg (%) was significantly different from the recommended data in parent stock management guide. With increasing experimental periods, the hatchability was deceased. The hatchability (%) of this farm was lowered as compared to recommended data in parent stock management guide. The analyzing of concerned production traits of this farm revealed that production and nutritional management need more attention in this laying parent stock unit.

This study was carried out to determine the nutritional value and the effect of different levels of prosopis juliflora pods (fruit contain seed and pod) on laying hen performance. The amount of AME, AMEn, TME and TMEn of prosopis juliflora were 3041.81, 3041.75, 3591.51 and 3592.97 kcal/kg, respectively. Crude protein, crude fiber, ash, crude fat, calcium, phosphorus, total tannins and total extractable phenolic were 11.75, 18.8, 0.5, 1.60, 0.55, 0.09, 5.03 and 4.8 percent, respectively on dry matter basis. There were significant differences for TME and TMEn among treatments (P <0.05). In order to study the effects of mesquite pods on laying hens performance, 120 white Leghorn laying hens(at 47 weeks of age) were allocated in a completely randomized design with four treatments and six replications (five hens in each replicate) for 14 weeks (two weeks for adaption and 12 weeks for sampling). Experimental treatments were diets with 0, 5, 10 and 15 percent of mesquite pods. The results showed that there were significant differences (P< 0.05) for egg production, egg mass, feed intake, feed conversion ratio, albumen height, haugh unit, egg shell weight and specific gravity among experimental groups. In conclusion, it is suggested that Prosopis juliflora pods can be included up to 10% in diet of laying hens.

This experiment was conducted to evaluate effects of different levels of mineral and vitamin premixes with wheat and corn base diets on performance and egg traits of laying hens. Experiment carried out as 2*5 factorial include wheat and corn base diets and 5 levels of minerals and vitamin premixes (0, 0.25, 0.35, 0.45 and 0.55 percentage) in a completely randomized design with 360 Hi-Line (W36) laying hens from 65 to 77 weeks in 10 treatments, 3 replicates and 12 hens in each replicate for 12 weeks. The results showed that diets composition, level of mineral and vitamin premixes, and interaction between them significantly affected the performance and egg traits of laying hens.