تخم ‏مرغ

Egg is one of the most valuable food items in the human diet. Several factors, such as diseases, bird age, diet, temperature, humidity, transportation, and storage time can affect the quality of eggs. The longer the storage time, the more CO2 penetrates the eggshell, particularly at room temperature, resulting in decreased internal quality. Eggs are a perishable product and must be stored in the refrigerator from production to consumption. Refrigeration increases production costs and ultimately leads to an increase in the final product price. Currently, there is a growing interest in developing effective methods to preserve the internal quality of eggs. The use of edible coatings after washing the eggs can help preserve the internal quality of the eggs during long-term storage. Edible coatings are an available technology that is currently used to control moisture, gas exchange, and oxidation processes for many products. The use of suitable active and antimicrobial edible films and coatings can potentially reduce the microbial load of egg surfaces, reduce undesirable changes, and increase their shelf life. Proteins are commonly used as film-forming materials. Proteins that have been previously investigated for egg coating development include whey protein isolate or concentrate, zein, and rice protein concentrate. Chicken feathers are a by-product of the poultry industry and are mostly disposed of without any processing, causing severe environmental pollution. To date, hydrolyzed feather protein has not been reported as an egg coating, so this study investigated the effect of hydrolyzed feather protein coating at two concentrations on the shelf life of chicken eggs under room temperature storage conditions.

In this study, a total of 120 fresh white-shelled eggs were obtained from Hy-Line W36 laying hens. The eggshells were washed to remove any surface contamination, then the eggs were numbered and randomly selected for each coating method. The samples were divided into three treatments of 40 eggs each treatment in a completely randomized design. The treatments included control (0%, without coating), a coating containing 10% (w/v) hydrolyzed feather, and a coating containing 20% hydrolyzed feather. Pure glycerol (Serva, Germany) was added to hydrolyzed feathers (2% w/v). The feather hydrolyzed protein was prepared at Tarbiat Modares University using alkaline hydrolyzed raw chicken feathers obtained from a commercial broiler slaughterhouse (Iran Borchin, Tehran). The chemical analysis of hydrolyzed feather protein was performed based on standard methods (dry matter, protein, ash, and fat), and the amino acid profile of the protein was also tested. Some nutritional or toxic important minerals were also measured. Egg weight, Haugh units, albumen weight, yolk weight, yolk color, albumen pH, yolk pH, and shell strength were measured during storage weeks 0, 1, 2, 3, and 4.

According to the data of this study, the height of the egg white and Haugh units in the stored eggs were significantly affected by the experimental coatings (P<0.05). The height of the egg white and Haugh units were significantly higher in the treatment with 20% hydrolyzed protein coating compared to other treatments (P<0.05). The yellowness of the egg yolk was significantly affected by the experimental coatings in the third week (P<0.05). The highest egg quality score was observed in the first and third weeks in eggs with 20% hydrolyzed feather protein coating (P<0.05). The eggshell characteristics were not affected by the experimental coatings. The egg white and yolk percentages were not affected by the experimental coatings. The pH of the egg white in the first and third weeks decreased significantly in eggs with 20% hydrolyzed feather protein coating compared to other treatments (P<0.05). The pH of the yolk was not affected by the experimental treatments. The pH in both the yolk and egg white increased over time. Eggs with coating had significantly less weight loss compared to uncoated eggs (P<0.05). The lowest weight loss was related to eggs with 10% and 20% hydrolyzed feather protein coating, which had a significant difference with uncoated eggs (P<0.05). The weight loss after seven days of storage in uncoated eggs (2.12%) was almost double the weight loss in coated eggs (1.16%). The weight loss after 14 days of storage at room temperature in uncoated eggs (4.21%) was almost double the weight loss in coated eggs (2.35%). The weight loss after 21 days of storage at room temperature in uncoated eggs (6.8%) was almost double the weight loss in coated eggs (3.35%). The weight loss after 28 days of storage at room temperature in uncoated eggs (8.27%) was almost double the weight loss in coated eggs (4.80%). Based on the results of this study, it was found that the use of hydrolyzed feather protein coating can improve the internal quality of eggs during the storage period. For future research, it is recommended to conduct further studies on the effect of hydrolyzed feather protein coating on the quality characteristics of eggs during storage. Previous studies have been conducted on improving the internal quality of eggs during storage using protein coatings with different hydrolysis. Some of these studies have shown that protein coating with hydrolysis can significantly improve the quality characteristics of eggs. Additionally, some studies have been conducted on the effect of protein coating using different proteins such as rice protein, meat protein, whey protein isolated, or whey protein concentrate and zein.

There was no significant difference in weight loss between 10% and 20% hydrolyzed feather protein coverage in different weeks, but the 10% hydrolyzed feather protein coverage provided better protection against weight loss. Since weight loss is mainly due to eggshell water evaporation, it was observed that despite being thinner, the 10% hydrolyzed feather protein coverage provided better protection compared to the 20% hydrolyzed feather protein coverage. Therefore, the use of coverages during egg storage can increase shelf life while maintaining egg quality.

Sustainable use, development and conservation of poultry genetic resources are of particular importance for agriculture, food production, rural development and the environment (Besbes et al. 2007). Indigenous chickens are often considered as a support for low input backyard or free-range system of production in rural, semi-urban and nomadic areas (Haunshi et al. 2019). Native chickens have unique characteristics such as ability to adapt to adverse environments, hardiness, broodiness and aggressiveness to protect their chicks, and more. However, low genetic potential is one of the identified limitations for increasing the productivity of native chickens along with inadequate nutrition and disease prevalence (Magothe et al. 2012a). The inbreeding accumulation and the decline in genetic diversity that occurs due to the mating of related animals in closed populations negatively affect phenotypic values and additive genetic variance (Falconer and Mackay 1996). Inbreeding, which occurs because of mating of related animals in a population, often occurs in the closed and small populations. The negative consequence of inbreeding is referred to as inbreeding depression, which has become a major concern in research related to evolution, ecology, and conservation biology (Reed et al. 2012). In small populations in particular, the inbreeding depression is significant in reproduction issues and has important consequences for the population's ability to evolve and adapt to environmental changes and ultimately their longevity (Leroy 2014).Increasing the inbreeding rate in closed populations of indigenous chickens' farms may negatively affect the increase in population productivity following the selection process and have destructive effects on improving economic traits in the population. Therefore, considering the importance of the issue, it seems necessary to monitor the inbreeding rate as well as the resulting depression in the under selection closed population of breeding station of Khorasan Razavi indigenous fowl.

In order to estimate the inbreeding rate and evaluate its effects on some important economic traits the pedigree data of 38489 birds collected during 2006-2017 in breeding station of Khorasan Razavi indigenous fowl were used. First, the pedigree data of the studied traits were edited using Foxpro and Excell software and then the files required for data analysis were prepared. The eight traits including average egg weight (AEW), egg number (EN), egg weight at 1st day of laying (EW1), age at sexual maturity (ASM), weight at sexual maturity (WSM), body weight at 12 weeks of age (BW12), body weight at hatch (BW1) and body weight at 8 weeks of age (BW8) were studied. The inbreeding coefficients of all birds recorded in the pedigree were estimated using the CFC program (Sergolzai et al. 2006). The inbreeding coefficients of the birds were divided into different categories. Then, the mean changes of inbreeding during different generations were evaluated and the amount of inbreeding changes in each year was calculated using SPSS software by fitting linear regression of inbreeding per generation. Also in this study, regression coefficients of studied traits on individual and maternal inbreeding percentage were estimated with the REML procedure of WOMBAT software (Meyer 2007) through different models.

The results showed that about 57% (21892 birds) of all birds registered in the pedigree were inbred. The mean of individual and maternal inbreeding varied relatively little over 12 generations. The mean inbreeding of all birds and inbred birds was estimated to be two and three percent, respectively. The highest and lowest inbreeding rates were three and 0%, respectively. As the results show, despite the closed raising and selection of the population and also the increase in the probability of inbreeding in the population, the inbreeding rate has been increased with a relatively low slope over the generations. In general, during the studied generations, the average coefficient of individual and maternal inbreeding in the whole population showed an increasing trend, so that by fitting the linear regression of inbreeding to the generation, the rate of changes in individual and maternal inbreeding was estimated to be about 0.005± 0.03 and 0.004± 0.02 per generation, respectively. In a study conducted on the Isfahan improved native chicken population (Jelokhani et al. 1400), researchers estimated the rate of individual and maternal inbreeding changes per year for the all population by fitting linear regression of inbreeding per generation to 0.006± 0.05 and 0.005± 0.04, respectively, which is approximately consistent with the results of the present study. In this study, 43.12% of the birds were non-inbred and the rest of the birds (47.68%) were grouped in six different inbred groups. The results showed that among the inbred groups, the most inbred birds (47.68%) were birds with inbreeding coefficients between 0 and 5%, which indicates that the population inbreeding is relatively low. Various studies have been performed on the inbreeding rate of domestic chickens in the country; the results are consistent with the results of the present study. For example, the results of a study on 26 generations of genetically improved domestic chickens of Mazandaran showed that, the rate of inbreeding for this population is relatively low (Ghorbani and Omrani 1399). In another study to estimate the inbreeding rate of Indigenous Kokok balenggek chicken (KBC) population in Indonesia, the researchers estimated the inbreeding coefficient to be 0.0031 (0.31%) and concluded that considering the inbreeding rate of herd is less than one percent, and inbreeding less than one percent indicates that one percent of heterozygosity is lost in one generation, the population is not endangered (Rusfidra et al. 2014). In another study on the population size of 37 protected local chicken breeds in five European countries, the relatively low inbreeding rates (0.02 to 0.71%) was reported (Spalona et al. 2007). In our study, the highest effect of individual inbreeding was shown on BW12. In this trait, for a one percent increase in inbreeding rate, the body weight decreases by 1.17 grams. Based on the another study performed on the Isfahan improved native chicken population (Jelokhani et al. 1400), it was shown that for every one percent increase in individual and maternal inbreeding, the WSM is reduced to 3.97 and 1.38 grams, respectively. In another study conducted on Mazandaran native fowls, the results showed that for every one percent increase in individual inbreeding, body weight decreased for the traits including BW12, BW8 and WSM (Ghorbani and Emrani 1399). The results of another study on the improved Fars native fowl revealed the greatest effect of inbreeding on body weight traits (8 and 12 weeks). In this study, for every one percent increase in individual inbreeding, body weight at 12 and 8 weeks decreased by 2.14 and 1.07, respectively (Jelokhani and Ghorbani, in press).

According to the findings in the present study, since the population is closed and under selection, the probability of inbreeding in the population is high. However, because there are controlled matings in the population of breeding station of Khorasan Razavi indigenous fowl, the inbreeding rate in each generation has increased slightly, which shows the appropriate management practices are running in selecting the best birds. Best management practices such as controlling the matings between birds can prevent an increase in population inbreeding as well as its possible negative effects on the traits.

Vitamin D3 is one of the important vitamins in calcium metabolism, which increases the active transport of calcium and phosphorus in the intestinal epithelium. However, the mechanism by which vitamin D3 increases the absorption of calcium and phosphorus is not fully understood. The active form of vitamin D3 or 1,25-hydroxycalciferol is transported to the nucleus of the intestinal cells. In the presence of 1, 25-hydroxycalciferol, a specific RNA is secreted from the cell nucleus, which is translated into a specific protein by the ribosomes, thereby increasing the uptake of calcium and phosphorus. The primary role of 1, 25-hydroxyvitamin D3 in vertebrates in regulating calcium homeostasis is the direct action of 1,25-hydroxyvitamin D3 on the gut, kidneys and bones by inhibiting the production of parathyroid hormone in the parathyroid glades. Vitamin C prevents stress by preventing the release of corticosteroid hormones, which can be effective for bird function, egg production and reducing mortality. In the liver, vitamin D3 is converted into 25-hydroxycalciferol, which is later converted into calciferol hydroxylase (activated by vitamin C) in the kidneys by the enzyme 25-hydroxy molecule. This metabolite increases the absorption of calcium and phosphorus from the intestinal wall and renal tubules. The aim of this experiment is therefore the effect of vitamin D3 and vitamin C on performance, egg quality and hatchability in broilers breeder hen at the end of the production period.

A total of 240 broiler breeder hens and 24 cockers (Ross 308) were distributed in a 2×2 factorial arrangement including two levels of vitamin D (3500 & 5500 IU) and two levels of vitamin C (0 & 150 mg/kg) with 6 replicate pens of 10 hens and one cock each. The experiment lasted for 12 weeks (from the age of 49 to 61 weeks), and during the trial, the performance traits production and hatchability were recorded. Every 28 days 4 eggs were evaluated for internal and external quality.

The results of the study showed that the main effect of vitamin D3 had a significant impact on egg weight, with higher concentrations resulting in a reduction in egg weight. However, there was no significant effect on other performance parameters. The main effect of higher concentrations of vitamin D3 was an increase in the number of hatching eggs, shell percentage, shell thickness, specific gravity of the eggs, a decrease in the percentage of egg breakage. However, this effect was not significant for other parameters. Increasing the level of 1,25 hydroxycalciferol significantly increased plasma calcium levels, which led to increased renal 1-alpha-hydroxylase activity, envelope secretion, reduced oocyte rupture, resulting in increased hatch fertility. The main effect of vitamin C significantly increased production percentage and reduced feed conversion and feed consumption per egg. However, there was no significant effect on other parameters. Addition of vitamin C significantly increased external characteristics of the eggs, including shell proportion, shell thickness, shell ash and phosphorus, number of hatching eggs, but reduced the number of broken eggs. However, there was no significant effect on internal parameters, except for yolk color. The use of vitamin C activates the enzyme 25-hydroxycholecalciferol hydroxylase to produce 1,25 hydroxycalciferol, which increases calcium absorption from the intestinal wall and reduces the number of ruptured eggs. Regarding the interaction of different levels of vitamin D3 and vitamin C, the results showed that higher levels of vitamin D3 and vitamin C increased production percentage, egg mass, number of hatching eggs, shell thickness, phosphorus and FCR. Intake in the egg removed significantly increased, but the number of broken eggs decreased.

In general, according to the results of the present experiment, it can be concluded that the use of vitamin C in an amount of 150 mg / kg with 5500 IU of vitamin D3 can increase the production percentage, increase the mass of eggs and improve the feed conversion ratio. It can also increase shell thickness and the number of chickens produced weekly and over the period, decrease the number of broken eggs, increase the number of hatching eggs, reduce feed intake per egg and feed intake per chicken at the end of the broiler breeder production period.

 Camellia sinensis is a species of evergreen shrub or small tree that its leaves is used to produce tea. The difference in the flavour, colour, and name of the tea depends on how the leaves are processed. There are four basic types of tea: black tea (tea leaves that are exposed to the air and allowed to fully oxidise or ferment, changing the leaves from green to black), oolong tea (it falls between black and green tea), green tea (less processed and not fermented), and white tea (the least processed of all tea). Green tea has over 200 bioactive compounds and contains over 300 different substances. The chemical composition of tea, composed of polyphenols such as catechins and flavonoids, alkaloids such as caffeine, theophylline, essencial oils and other compounds which are unknown (Carry et al. 2007). In most researches, green tea has beneficial effects due to the presence of catechins as powerful antioxidants. Ariana et al. (2011) reported that adding 1.5% green tea leaf to laying hens diet caused a decrease in feed intake compared with control diet. Bing et al. (2018) reported that up to 1% green tea leaf did not affect production performance, but levels above 1% reduced laying percentage. Some sources even reported better performance for the birds fed even lower levels of green tea. Abdul Azim (2005) reported that adding 0.75% of green tea improved the laying yield and feed conversion rate of Japanese quail. Due to complex compounds such as catechins, flavonoids and phenolic acids, antioxidant and cholesterol lowering effects of tea have been proved. Ariana et al. (2011) reported the reduction of serum cholesterol of laying hens fed 1.5% green tea leaf and Zeinab et al. (2010) showed an improvement in antioxidant capacity of birds fed green tea leaves. Due to lack of research on the effects of Iranian tea on laying hen performance and extensive cultivation of this product in Iran, this study was conducted to evaluate the effects of different levels of green tea on production performance, serum lipids, and antioxidant capacity of laying hens.

 One hundred and twenty W-36 white leghorn laying hens (60 wk age) were assigned to five treatments with five replicates and four birds in each replicate based on a completely randomized design. Dried Iranian green tea leaf provided from Lahijan city tea farms. Dietary treatments including: 1) Basal diet based on a corn-soybean meal 2) basal diet with 0.5 % green leaf tea powder, 3) basal diet with 1% green leaf tea powder, 4) basal diet with 1.5% green leaf tea powder, and 5) basal diet with 500 g/ton vitamin E. All of the diets were fed to birds for seven weeks. The diets were isocaloric and isonitrogenous. Egg production rate, egg weight, feed consumption, egg mass, and feed conversion ratio were recorded weekly and reported as hen day basis. Egg mass was calculated by multiplying the total number of eggs laid per hen by the average egg weight. At the end of the experiment, two birds from each replicate (close to cage average weight) were selected. Blood samples were collected from the wing and serum was separated. Total antioxidant capacity (TAC), lipid peroxidation (MDA), total cholesterol, triglyceride, and high-density lipoprotein (HDL) were measured using analytical kits. All data were analyzed by ANOVA procedure described by the SAS Institute (2009). Tukey test was used to determine the significant differences between treatment means.

 The results showed that feed intake, egg production rate, and egg mass of birds fed diets containing more than 0.5% green tea leaf powder (GTLP) decreased significantly and feed conversion ratio increased as compared with control group. Production performance criteria was not affected in birds fed vitamin E as compared with control group. Similarly, Bing et al. (2018) showed that feeding up to 1% of GTLP in layer hen diets did not affect production performance; but, levels above 1% reduced egg production percentage. Also, Bing et al. (2018) showed that the use of higher than 1% GTLP in diet had negative effects on production performance. Kojima and Yoshida (2008) and Wei et al. (2012), similar to our results, reported a decrease in feed intake even at lower levels of GTLP in the diet. Yaman et al. (1999) showed that egg weight decreased using 0.67% green tea extract in drinking water. As compared with control group, birds fed diet containing 1.5% GTLP had lower serum triglyceride, total cholesterol, and VLDL concentrations. Similarly, Ariana et al. (2011) reported a reduction in serum cholesterol of laying hens fed 1.5% GLTP. Shishikoura et al. (2006) reported that catechins in green tea is a potent inhibitor for cholesterol and triglyceride absorption in small intestine. Panala et al. (1997) showed that green tea polyphenols can reduce the production of free radicals produced in the cell and Ishikawa et al. (1997) reported that green tea flavonoids could be able to boost animal antioxidant capacity. Sahin et al. (2010) reported a decrease in malonildialdehyde (MDA) by feeding GLTP in birds. In the present experiment, serum antioxidant capacity was increased, but   MDA   and lipid peroxidation index were decreased in the birds fed diets having 1.5% GTLP or   vitamin E (P<0.05).

Although the use of at least 1% GTLP had negative effect on production performance of laying hens, it reduced blood cholesterol and triglycerides, while increased antioxidant capacity parallel to vitamin E diet.

The term “guinea fowl” is the common name of the seven species of gallinaceous birds of the family Numididae, which is originated from Africa and their meat and eggs are very popular. Eggs, one of the versatile foods, inexpensive and high nutritious, supply well balanced nutrients that affect human health. An egg is a rich source of protein and then have high biological value. Eggs contain essential proteins, fats, vitamins except vitamin C, minerals mainly including calcium, phosphorous, iron, magnesium, zinc, selenium, potassium and sodium, and bioactive compounds, and their compositions could be affected by type of bird, heredity, strain, age, hen diet, and environmental conditions such as season and rearing condition. An average weight of egg in commercial strains is usually 55 g and this trait mainly influenced by diet mainly the concentration of methionine and lysine and energy content. Distribution of proteins in egg component is equal between egg yolk and egg white. Other hands, the egg yolk is the major part of lipid, mineral and vitamins. The high consumer preferences of guinea fowl and its products demonstrate that guinea fowl is valuable and have high marketing potential. Compared to native hens and chickens, the guinea fowl’s benefits are: low production and rearing cost, high meat quality, greater capacity to scavenge for insects and grains, better ability to protect itself against predators and low incidence of common poultry diseases than chickens including parasites Newcastle Disease and Fowl Pox. In order to improving household protein supply and income and Because of the great potential for increasing guinea fowl production for smallholder farmers need to evaluate their products and specifically egg. This study was conducted to determine internal and external egg quality traits, chemical composition and fatty acid profile of yolk of East Azarbaijan province guinea fowl and compare their values with table hen eggs values.

A total of 50 clean eggs were obtained from Bonab guinea fowl research station by simple random sampling method. The guinea fowl breeders were at the same age and fed with similar diets. In order to compare of these values with table eggs values, 50 clean table eggs were purchased from a market. After sampling, the eggs were immediately transferred to the lab and internal and external egg quality traits were individually measured. Descriptive statistics of traits were determined using SAS software by univariate procedure and unpaired t-test was used to compare the data of guinea fowl eggs with table eggs data.

The results of this study showed that the mean external egg quality traits of guinea fowl eggs such as egg weight, shell ratio and thickness, egg shape index and egg volume were 40.736 g, 15.604% , 0.718 mm, 78.801 and 42.035 cm3, respectively. The mean of internal egg quality traits of guinea fowl eggs such as yolk and albumin percentage, haugh unit, yolk color, pH of yolk and albumin were 31.418%, 52.977%, 78.030, 8.80, 6.592 and 9.332, respectively. Also, the average external egg quality traits of table eggs such as egg weight, shell percentage and thickness, egg shape index and egg volume were 61.371 g, 9.080 %, 0.665 mm, 76.852 and 63.065 cm3. The mean of internal egg quality traits of table eggs such as yolk and albumen percentage, haugh unit, yolk color, pH of yolk and albumen were 31.334%, 59.585%, 75.075, 4.70, 6.431 and 9.415, respectively. The average of shell thickness of guinea fowl eggs were higher than hen eggs that indicate the shell strength of guinea fowl eggs is higher than table eggs. For determinating of chemical composition of guinea fowl and table eggs, 5 mixed samples (from each 10 eggs) were prepared. The amounts of albumin and yolk dry matter, albumin and yolk crude protein, yolk ether extract, and ash contents of shells were 13.526 and 46.662, 81.696 and 33.652, 31.456, and 89.924%, respectively and these values in table eggs were 12.730 and 45.770, 84.384 and 33.064, 30.406 and 77.564, respectively. The ash content of egg shells in guinea fowl was higher than that of table eggs. This is consistent with shell ratio and shell weight. Cholesterol content of the guinea fowl and table eggs were 1605 and 1391 mg/100 g of yolk, respectively. To determine the fatty acid profile of egg yolk of guinea fowl and table eggs, 5 mixed samples were selected and the fatty acids contents were measured by the gas chromatography method. In guinea fowl, the highest fatty acids content of egg yolks were palmitic acid, oleic acid and linoleic acid, with the amounts of 28.274%, 34.686% and 20.130% of total fatty acids of egg yolk, respectively. The highest and the lowest fatty acid content of table egg yolks were palmitic acid and docosapantaenoic acid with values of 29.176 and 0.026, respectively. The sum of saturated fatty acids (SFAs), monounsaturated fatty (MUFAs) acid and polyunsaturated fatty acids (PUFAs) in the egg yolk of guinea fowl were 38.144, 38.712 and 22.090 % and for table eggs were 40.638, 32.280 and 19.361 %, respectively. The sum of PUFAs of guinea fowl eggs significantly higher than table eggs (p<0.05). Sum of n-3 PUFAs in table eggs was higher than guinea fowl eggs (0.567 vs 0.342) and unlike n-6 fatty acids, the guinea fowl eggs had higher value in comparison of table eggs (21.746 vs 18.694). PUFAs and specially, n-6 PUFAs have a hypo-cholesterolemic effect than n-3 PUFAs and therefore guinea fowl eggs can decrease cholesterol content of serum.

According to the results, the level of cholesterol, n-6 fatty acids and n-6 to n-3 fatty acids ratio of guinea fowl eggs were higher than those of table eggs. Also, the sum of PUFAs and the sum of SFA to sum of MUFA ratio in yolk samples of guinea fowl eggs in comparison with table eggs were higher.

The current research was designed to evaluate the effect of dietary addition of garlic powder, Cornerian cherry fruit powder (CH) and a mixture essential oil of castor and cashew nut shell (EO) on performance, egg quality and some blood parameters in commercial laying hens. One hundred and twenty-eight 58-wk-old LSL laying hens were used in 4 treatments with 4 replicates and 8 birds per each in a completely randomized design. The experimental diets included: 1) Basal diet; 2) Basal diet +1% garlic powder; 3) Basal diet+1% CH and 4) Basal diet+0.15 percent EO. The experimental diets were fed from 59 to 63 weeks of age. The productive performance was recorded from 61 to 63 weeks of age and blood and egg yolk parameters measured at the end of the experimental period. There were no significant differences in laying hen performance among all treatments. Albumen height and Haugh unit was increased in CH compared to the control group (p<0.05). The blood cholesterol, HDL, triglyceride and aspartate aminotransferase and alanine aminotransferase enzymes did not show any significant difference among treatments. The garlic and CH powders significantly decreased egg yolk cholesterol concentration (p<0.05), however it was not significantly affected by the EO. Finally, it was concluded that addition of CH and garlic powder in the diet of laying hens could improve the egg quality and reduce yolk cholesterol concentrations.

This study was conducted to investigate the effects of different levels of black cumin powder on performance, yolk cholesterol content and egg oxidative stability in laying hens. A total of 96 Leghorn laying hens (Hy-Line W-36) of 25 weeks old were randomly distributed among eight cage replicates of three birds each. Experimental diets consisted of different levels (0, 5, 10 and 15 g/kg of diet) of dietary black cumin powder. The experimental period lasted for a total of 6 weeks. The results showed that the highest feed intake observed in hens were fed with rations included 15 g/kg of black cumin (P<0.05). Supplementation of black cumin had no significant effects on egg mass and feed conversion ratio. The effect of black cumin on shell quality indices were not significant. The highest egg yolk weight obtained from hens were fed the black cumin supplemented diet (15 g/kg of diet) (P<0.05). There were no significant difference in yolk cholesterol and malondialdehyde content between hens fed black cumin supplemented diets and hens fed the control diet. Therefore, it can be concluded that adding of black cumin (15 g/kg) to laying hens diet had positive effects on feed intake and egg yolk weight.

Nutrition is the most important and cost effective factor in poultry production. By reducing the nutritional cost, the production efficiency increases and the use of feed additives as growth promoters in poultry feeding is a way to achieve this goal. Medicinal plants have beneficial properties due to the biological active compounds such as terpenes, phenols, ketones, esters, and alkaloids that improve the animal performance and health (Abaza et al. 2008). From the category of medicinal herbs, Nettle (Urtica dioica) and Elaeangus (Elaeagnus angustifolia) can be introduced which both are from Rosales order (Mohammadi et al., 2017). Nettles may be used in veterinary medicine because of its high levels of nutrients such as amino acids, minerals, vitamins, active compounds such as tannin, folic acid, salicylic acid, carvacrol, and thymol (Fu et al., 2007). Elaeangus is also a shrub or tree of the Elaeagnaceac family of the genus Elaeagnus, called Elaeagnus angustifolia (Khakrizi & Salehi, 2012). Phytochemical experiments showed that the Elaeangus contains high amounts of flavonoids, cytosterols, carbohydrates, folic acid, and ascorbic acid. It also contains potassium, magnesium, sodium, iron, calcium, zinc, malic acid and calcium malate. It is rich source of fatty acids including linoleic, palmitoleic, and palmitic acids (Ramezani et al., 2001). In general, natural-food products, especially medicinal plants containing active biological compounds, can create a favorable outlook to be used in poultry nutrition. The use of medicinal plant resources as feed additive is growing rapidly due to their active aromatic compounds, which benefits the host animal (Mohiti Asl et al., 2011). The experiment was designed and carried out using 128 commercial laying hens of W36 strain at 75 weeks of age with 4 experimental treatments, each group with 8 replicates and 4 birds per each replicate. A 14-day period was conducted to adapt the layers into the experimental diets. After this period, the main stage of the experiment consisted of 3 consecutive periods, each for 21 days, which totally with 11 weeks of the entire study period. During the experimental periods, the birds had free access to water and feed and the experimental diet was adjusted to maintain the requirements of the Hy-Line W36 (2014) breeding guidebook. The experimental groups consisted of: 1 (control): basal diet; 2: basal diet with 1% nettle powder; 3: basal diet and 1% Elaeangus fruit powder; 4: Basal diet plus 0.5% of nettle powder and 0.5% of Elaeangus fruit powder. The temperature and lighting program was also carried out according to the guide for breeding white Leghorn chicken (Hy-Line W36 strain). To evaluate the egg quality, three egg samples were taken and each egg sample was selected from each replicate. The sampling was done at the end of each periods. After sample collection, the weight of individual eggs were recorded using a digital top balance with 0.01 gram accuracy in the laboratory and later their individual specific gravity index were measured using a floating method in a salt water solution. The egg white quality was carried out by the Egg Multi Tester instrument (EMT-5200), (Leeson and Summers, 2005). To determine the thickness of the shell, Ultrasonic thickness Gauge (Echometer 1062 - Maks - USA) was used and to measure the shell resistance, the model-ll-MaksUSA device (Egg Shell Force Gauge) was used and the yolk color index was measured by the Rosche yolk color fan (Hosseini & Arshami, 2010). Shell weight were measured using a digital balance with an accuracy of 0.1 g (Leeson and Summers, 2005). The statistical analysis was done using SAS (2001) version 9.1. The highest amount of Haugh units belonged to the experimental group of Elaeangus fruit powder (1%) compared with control group and 0.5% nettle powder and 0.5% Elaeangus fruit powder group. The effect of experimental periods on the Haugh unit was significant and the highest number of Haugh units belonged to the second period, which had no significant difference with the first period, but showed a significant difference with the third period (P<0.05). The height of the egg white was statistically decreased in group 4 compared with control group (P<0.05). The effect of experimental periods on the height of egg white was significant and the highest amount was observed in the first and second periods compared with the third period (P<0.05). The experimental periods also had a significant (P<0.05) effect on the egg shell thickness, in which the highest amount was observed in the third period compared to the second period (P<0.05). Also, the interaction effect of the experimental periods and treatments on shell weight was also significant (P<0.05). Sayiedpiran et al. (2011) did not show any significant improvement using combination of extracts of thyme, mint, and Pennyroyal. Vakili (2011) indicated that, addition of essential oil of thyme and fennel into the diet of the laying hens, significantly improved the Haugh unit scores. Bird’s age and production stage are the effective factors on egg shell structure. The reason for improving the Haugh unit is attributed to the age of the bird, so the young birds have more Haugh unit scores. Also, Azghadi et al. (2010) reported no improvement in yolk color index using 0.1, 0.2, and 0.3% levels of thyme and cumin extracts. Vakili (2011) also stated in a study that adding 40 mg/kg of thyme extracts to the diet of laying hens showed no significant effects on egg shell quality parameters. Probably the reasons like the high age of chickens and the high temperature of the environment had a negative effect on the amount of calcium absorption to make the shell (Vakili, 2011). Considering the results obtained from current experiment, it can be concluded that the use of Elaeangus fruit powder at 1% can be recommended to be used in layers diet.

Recently, there has been increased research on isomers of conjugated linoleic acid. Conjugated linoleic acid (CLA) is a mixture of several geometrical and positional conjugated isomers of linoleic acid (LA, C18:2) which involve a double bond at positions 8 and 10, 9 and 11, 10 and 12 or 11 and 1, but the c-9, t-11 and t-10, c-12 isomers are physiologically important. CLA is produced in the rumen as a result of incomplete bio-hydrogenation of Linoleic acid. When bio-hydrogenation is incomplete, CLA can escape the rumen and be absorbed through the gastrointestinal tract, thereby providing the peripheral tissues with various isomers of CLA. Due to production of CLA isomers in ruminant’s rumen, ruminant products, such as milk and meat are main CLA sources in human diets (Chin et al., 1992). CLA has been reported to have anticarcinogenic, hypocholesterolemic, and antiartherogenic effects in laboratory animals. Some reports showed positive effects of CLA isomers on egg production, egg quality, immune response, antioxidant status and gene expression in laying hens. It has been documented that layer hens meet some oxidative attacks during force molting (Siegel 1980), therefore, the aim of this study was to evaluate the effect of different levels of conjugated linoleic acid (CLA) on egg production performance, some blood biochemical parameters and immune response of laying hens in post-molting phase. Material and In this experiment, sixty W-36 White leghorn laying hens in post-molting phase (78 week) were assigned to 3 treatments with 5 replications and 4 birds each based on completely randomized design. The purity of CLA source used in this study was above 90% with mixture of 50% c9-t11 and 50% c10-t12 isomers. Experimental diets were 1) Control diet (basal diet containing 0% CLA), 2) basal diet+0. 25% pure CLA and 3) basal diet+0.5% pure CLA and after adaptation period, diets were fed for 4 weeks. Egg production, egg weight, feed consumption, egg mass and feed conversion ratio were recorded weekly. In the end of experiment, two birds from each replicate close to cage average weight, was selected, blood samples were collected from the wing and serum separated. Total antioxidant capacity (TAC), total cholesterol, triglyceride and high density lipoprotein (HDL) cholesterol and low density lipoprotein (LDL) were measured using analytical kits. Another bird per replicate with average cage weight selected, after injection of vaccine in breast muscle, two weeks later, immune response was measured based on Hemagglutination-Inhibition (HI) Test. All data were analyzed by ANOVA using the procedure described by the SAS Institute (2009). Tukey test was used to determine the significant differences between treatment means. Results showed that egg production rate and egg mass of birds fed 0.5 % CLA were significantly higher than birds fed control diet or diet containing 0.25 % CLA during whole experimental period, but egg weight and feed consumption were not affected by dietary CLA level. Also feed conversion ratio of birds fed 0.5 % CLA was significantly (P<0.05) lower than control birds or those fed diet containing 0.25 % CLA. Ahn et al. (1991) reported improvement in egg production of layer hens fed 1.5 % CLA but Cherian et al. (2007) reported that egg production and egg mass of laying hens were unaffected by incorporating 0.25% CLA during the peak production period. Also Bolukbasi and Erhan (2004) reported no significant effect of 1% CLA in laying hens diet on the rate of egg production. Total cholesterol, HDL, LDL and VLDL in blood serum of birds were not affected by dietary CLA (P>0.05) in present study, but serum triglyceride decreased significantly with increase CLA level (P<0.05). Similarly, Munday et al. (1999) reported that mice fed CLA had lower serum triglyceride. The beneficial effects of CLA might be related to the fact that CLA decreases the activity of lipoprotein lipase (Park et al., 1997). Ha et al. (1990) reported that CLA is an effective antioxidant, more potent than a-tocopherol and almost as effective as butylated hydroxytolune (BHT), but total antioxidant capacity in blood serum of birds in present study were not affected by dietary CLA (P>0.05). It is concluded that use of 0.5% CLA in post-molting diet of laying hens improved immune system and egg production performance and decreased blood serum triglyceride of birds.

The effect of environmental conditions on health indices, performance and reproduction of poultry such as hatchability of eggs is very important. In recent years, several studies have been paid to theeffect of electromagnetic and magnetic fields onliving organisms, physiologicalchanges, production and health (Adair, 1998; Baharara et al., 2008; Shafey et al., 2011). Animals and poultry are exposed to electromagnetic fields from various sources such as electric wiring, industrial electric furnaces, mobile telephones and electric motors. Electromagnetic fields might impact the biological processes. The electromagnetic fields would also appear to have some negative effects in poultry welfare and economic efficiency. The researchers reported that exposing cells to electromagnetic fields could cause DNA to break apart and thus affect how cells develop (Focke et al., 2010). The effect of artificially generatedelectromagnetic field of low frequency on survival of chick embryos was examined by Siddiqi et al. (2015) and Shafeyet al. (2011). The results of such studies are differentand recurrently controversial mainly becausedifferent induction frequencies and intensities aswell as different times of exposure to the effect of these fields were used.The aim of this study was to evaluate the effect of electromagnetic fields (EMF) on hatchability and some serum parameters of one- day old chicks.
Material and Number of 115 fertilized eggs divided randomly to five treatments each replication 23 eggs. Treatments included control group, EMF 2mT, 4 mT, 6 mT and 8mT with low frequency (50 Hz). Each treatment was exposed to electromagnetic fields for 2 hours. Four replicates with 23 eggs were allocated to each experimental treatment. Eggs were stored at room temperature (about 15-18°C). After the exposure of electromagnetic fields, 3 eggs from each treatment analyzed for egg quality parameters. At sampling, eggs were weighed and broken on to a flat surface where the height of the albumen and yolk were measured. The height of the albumen and yolk were measured using micrometer. Mortality was recorded on a group basis as it occurred. Hatching eggs were stored at 18°C and 75% RH. 115 eggs from five treatment groups were incubated in commercial setter and hatcher with 23 eggs in each of treatment group. The setter and hatcher were operated at temperatures of 37.5±0.5°C and 37.0±0.5°C respectively. Hatchability was calculated as the number of chicks hatched per fertile or total eggs. Haugh units were calculated from records of egg weight and albumen height as an indicator of interior egg quality. Haugh unit= 100 log (H 7.57-1.7W0.37), where H= height of the albumen and W= egg weight. At the end of the experiment, one-day chicks were slaughtered and blood samples were provided and analyzed for different parameters. Blood samples were centrifuged (at, 6500× g for 20 min) and serum was separated and then stored at -200C until assayed for measuring biochemical parameters (glucose, cholesterol, triglyceride, total protein, HDL, LDL, VLDL) using appropriate laboratory kits. The data obtained from the experiment were analyzed using SAS (SAS Institute, 2003) statistical programs with ANOVA procedure. Significant differences among treatments means were separated using Duncan, s multiple range test with a 5% probability.
There were no significant differences between treatments for parameters such as egg weight and egg large diameter. There were significant differences in the egg small diameter and albumen height (P It can be concluded that electromagnetic fields decreased levels of serum lipids but had not effect on hatchability and Haugh unit.

Selenium is an essential trace mineral required for normal growth and maintenance in poultry and specially contributes in glutathione peroxidase activity, an enzyme transforming the toxic hydrogen peroxide to harmless water and oxygen (Rotruck et al. 1973). Selenium may be present in inorganic or organic form in the diet and higher absorption being documented for the organic forms in poultry (Surai and Fisinin 2014). Selenium in its organic form shows higher bioavailability (75.7%) than selenium bound in the inorganic form (49.9%) (Mahan et al. 1999). Organic forms are part of proteins and include Se-Methionin and Se-Cystein. Organically bound selenium is mostly used in the form of Se-enriched yeast or other preparations. In addition to organic Selenium compounds, other sources have been tested and utilized, such as selenium-enriched algae Scenedesmus quadricauda, Se-enriched unicellular alga Chlorella (Travnicek et al. 2007) and Se-enriched yeast (Briens et al. 2013). Effects of various sources and levels of selenium in the diet on layers have been subject of a number of studies. Gjorgovska et al (2012) studied various levels of selenium yeast in layers and reported that supplementation of 460 mg/kg selenium yeast improved egg production performance comparing control birds. Similar findings have been reported by Heindl et al. (2010), who fed the layers up to 150 mg/kg selenium yeast. Attia et al. (2010) reported increase in egg weight of laying hens fed organic selenium. They reported that feed conversion ratio in laying hens fed diets containing 250 or 400 mg/kg Selplex, was lower as compared as control birds. Some researchers reported that immune response and activities of glutathione peroxidase in poultry plasma increased linearly with selenium concentration (Rama Rao et al. 2013; Singh et al. 2006). Zhang et al (2012) reported that low-selenium diet caused a decrease in the activities of total antioxidant capacity, superoxide dismutase, and glutathione peroxidase activity in birds. Their study demonstrated that chickens fed diets deficient in selenium exhibited lesions in immune organs, decreased serum interleukin-1β, interleukin-2 content, indicating that oxidative stress inhibited the development of immune organs and finally impaired the immune function of chickens. Gajcevic et al (2009) reported increase in glutathione peroxidase activity in layer hens fed up to 400 mg/kg selenium yeast in diet. It has been documented that layer hens meet some oxidative attacks during force molting (Siegel 1980), therefore, the aim of this study was to evaluate the effect of different levels of selenium yeast on egg production performance, glutathione peroxidase activity and immune response of laying hens in post-molting phase.
Material and Eighty W-36 leghorn laying hens in post-molting phase (78 week) were assigned to 5 treatments with 4 replications and 4 birds each by employing a completely randomized design. After one week adaptation of hens to cages and diets, the hens were fed with 5 levels of selenium yeast (Sel-plex) (0, 150, 300, 450 and 600 mg/kg) for a period of 4 weeks. Sel-Plex ® is Alltech's organic form of selenium yeast and each kilogram of Sel-pex contains1000 mg selenium. All diets were isocaloric and isonitrogenous based on corn-soybean. Egg production percent, egg weight, egg mass, feed intake and feed conversion ratio of birds were recorded weekly and reported as hen day basis. Egg mass was calculated by multiplying the total number of eggs laid per hen by the average egg weight. In the end of experiment, one bird per replicate with average cage weight selected, blood samples were taken and glutathione peroxidase (GPx) activity was measured using Autoanalyzer system. Another bird per replicate with average cage weight selected, after injection of Influenza vaccine in breast muscle, two weeks later, immune response was measured based on Hemagglutination-Inhibition (HI) Test. All data were analyzed by ANOVA using the procedure described by the SAS Institute (2009). Tukey test was used to determine the significant differences between treatment means.
Results showed that using 300 and 450 mg/kg selenium yeast in post-molting diet of layers, significantly increased egg production rate as compared with control ones (P It is concluded that use of 300 mg/kg selenium yeast could improve egg production rate, glutathione peroxidase activity and immune response of laying hens in post-molting phase.

Economically success incomerical and Native laying hen farms in some eaten is related to egg quality. So, egg quality is a one of the most important factor affecting hatchability and lead to increasing the egg demand. The current study was carried out in aim to estimate the genetic parameters for egg quality traits in Fars native fowls. To do this, 2000 pedigree recorded eggs were collected at Fars Native Breeding Center and external and internal egg quality traits were measured. Significance of environmental effects determined using GLM procedure by SAS software and those were considered in the mixed model analysis. Heritability, genetic and phenotypic correlations were estimated using ASREML software. The estimated heritability for egg weight and external egg quality traits including shell strength, shell weight, shell thickness were 0.21, 0.44, 0.23, 0.12. this parameter for internal egg quality traits including albumin height, albumin weight, Hough unit, yolk weight, yolk diameter were also estimated 0.17, 0.10, 0.17, 0.36, 0.13, respectively. Genetic and phenotypic correlations of egg weight with external and internal (except to yolk weight) egg quality traits were obtained positive. Both genetic and phenotypic correlations among external egg quality traits were found positive and ranged from 0.04 to 0.91. Yolk weight were negatively genetically correlated with yolk diameter and shell features (shell strength, shell thickness and shell weight). The genetic correlation of shell strength and traits such as albumin height, Hough unit, yolk weight and yolk diameter were low and in negative direction. The results showed that the selection for increasing egg weight lead to improvement of egg quality traits and decreased yolk weight in Fars native fowls.

Micronutrients such as Folic acid (FA) and Zinc (Zn) have important role in enrichment of egg with 5-methyltetrahydrofolate (5-MTHF).
This study was performed to evaluate the effect of FA and Zn on performance, egg quality and egg 5-MTHF content of Hy-line W36 hens from 52 to 58 weeks of ages.
Experimental diets were formulated using three levels of Zn (100, 130 and 160 mg/kg of diet) and four levels of FA (0, 5, 10 and 15 mg/kg of diet). Study was conducted by employing a completely randomized design with 3×4 factorial arrangement.
Egg production percent, egg mass and feed conversion ratio was significantly improved by supplementation of FA and Zn (P In conclusion supplementation of laying hens diets with FA and Zn not only improves performance of laying poultry, but also increases the 5- MTHF content of egg.

An experiment was conducted to study the effects of different dietary energy levels in the rearing period on performance and productive traits of layer hens during the laying cycle. 196-day-old layer chicks were randomly assigned to 7 treatments (2400, 2500, 2600, 2700, 2800, 2900 and 3000 Kcal ME/kg), with 4 replicates of 7 birds each. The treatment containing 2800 Kcal ME/kg was considered as the control group. Results showed that feeding different dietary energy levels had no effect on feed intake and weight gain (P>0.05). Even though, feed to egg ratio was increased by reduction of dietary energy levels, decreasing energy levels up to 2400 Kcal ME/kg had no significant effect as compared to control group (P>0.05). Feed intake per dozen eggs and egg number per hen were not affected by reducing energy level up to 2500 Kcal ME/kg, as compared to control group (P>0.05). In addition, diluting the dietary energy up to 2600 and 2700 Kcal ME/kg had no effect on egg production and time of laying commencement, respectively (P>0.05). In conclusion, feeding the treatment containing 3000 Kcal ME/kg, not only improved performance and productive traits, but also increased the average weight of each egg when compared to other treatments (P

To investigate the nutritive value of egg and the possible use of waste eggs and spray-dried whole egg, as alternative protein source in neonatal calves, an experiment was done using twenty female and male Holstein calves. The treatments were: 1) milk without egg (control), 2) milk contain 7.5% raw egg, 3) milk containhng 7.5% raw egg and biotin (1 mg/kg), 4) milk contain, 7.5% spraydried whole egg powder, in a 57/d feeding trial. Data were analyzed in a completely randomized design (CRD). The results showed that there were no significant differences between treatments on body weight (BW), average daily gains (ADG), dry mater (DM) intakes and feed conversion ratio (FCR) of calves. Digestibility of dry matter in control and milk containing 7.5% raw egg and biotin increased significantly. The concentration of cholesterol, triglycerides, high density lipoprotein (HDL), low density lipoprotein (LDL) and very low density lipoprotein (VLDL) were not significant difference versus treatment control. The Concentration of blood ferritin significantly increased by egg powder. There were no significant differences between treatments on IgG and total protein of blood calves. Results of experiment showed that feeding of calves with milk contain 7.5% egg, without negative effets on performance and blood parameters of calves.

The objective of this study was to assess the effects of soy oil sources، dietary vitamin E and vitamin C supplementation on serum and yolk total cholesterol (TC) and triglyceride (TG) and contents and egg oxidative stability in laying hens. A total of 300 Hy-line variety W-36 laying hen with 44-wk of age were used. Twelve corn-soybean meal-based diets containing; 3. 5% refined soybean oil (SBO)، recycled soybean oil (RSO)، or acidulated soybean oil soapstocks (ASO) each containing two levels of vitamin E (0 and 250 mg/ kg diet)، or two levels of vitamin C (0 and 250 mg/ kg diet) were used in a completely randomized design trial with a 3×2×2 factorial arrangement. The yolk oxidative stability was determined on 3 groups of fresh eggs after refrigeration at 5°C for 1، 15، and 30 days. The results showed that serum concentrations of TC and TG، and yolk TC content were not affected by dietary oil sources (P>0. 05). Dietary inclusion of RSO and ASO، however، increased (P<0. 05) egg TG content. Although dietary supplementation of vitamin E had no marked effect on serum and egg lipid profile، supplemental vitamin C decreased (P<0. 05) egg TG. No interaction of dietary fat sources and vitamin supplementation was observed on serum TC and TG or egg TC. However، there was a positive interaction between vitamin E and vitamin C for yolk TG content، so that the presence of both vitamins had more reducing effect on yolk TG. On the other hand، 30 days egg storage decreased (P<0. 05) yolk oxidative stability and dietary vitamin E supplementation improved stability index. These results confirm the fact that egg triglyceride is more prone to dietary manipulation compared to egg cholesterol.

This study was conducted to evaluate the effects of germinated barley on the performance and egg quality of laying hens in different storage conditions. Six experimental diets consisted of Corn diet (corn basal diet), Barley diet (barley basal diet), Enzyme diet (barley basal diet plus enzyme Safizym) and 33, 66 and 100% germinated barley diets (in which barley was replaced by germinated barley at 33, 66 and 100 percent, respectively) were fed to laying hens for 10 weeks. Four replicates of 5 hens were allocated to each experimental diet. Results of experiment indicated, feed intake and feed conversion ratio were significantly for enzyme diet (124.09 gr and 2.13, respectively) and germinated barley 100% (125 gr and 2.04, respectively) than hens fed barley diet (129.68 gr and 2.28, respectively) (P<0.05). Egg weight in germinated barley 100% was significantly lower than barley diet (63.63 and 65.29gr, respectively), but egg production (95.97 and 87.61%, respectively) as well as egg mass production (61.08 and 57.67 gram per day, respectively) were higher (P<0.05). Storage of eggs resulted to significant (P<0.05) decrease of specific gravity (from1.087 to 1.066), albumin index (from 10.70 to 5.52), albumin percent (from 54.97 to 55.91), Haugh unit (from 90.47 to 68.03) and yolk index (from 42.90 to 38.12). Therefore, use of germinated barley in egg laying diets can improve hen performance and egg storage decreases egg quality.

When the weather is getting cold in winter and according to temperature limitation, egg production decreases in rural areas and other avicultures that suffer from keeping optimal temperature quantitatively and qualitatively. According to this point that whey has a high dietary and probiotic value and in high volume is being produced in rural areas as an accessory product and often is being thrown away therefore; we can decrease cost of sustenance and conquest on cold stress with adding a natural valuable source, a probiotic substance, like whey to egg mash. The first priority in this study is determination of effectiveness about whey in laying of domestic fowls in winter and cold stress. In this study 90 domestic fowls in 38 weeks old and duration of 30 days were used. The study was completely random and with 3 cares and 3 repetitions (9 cages with 10cases in each of them) were done. The testable cares were in order: (1)the first group(witness) that received basal egg mash in total period (based on corn and soya) and was kept in 8-12c, (2)the second group received basal egg mash in total period and was kept in 16-20c, (3) the third group received basal egg mash with 5% solution of whey and was kept in a same temperature like witness group, then after 10 days from care performance, number of eggs and some of their qualitative indexes in each group were analyzed and measured. The results of this study show that the number of eggs in the second and the third group increased 60% and 50% sequentially, But; the noticeable point was that the eggs of third group had been increased in some indexes like average weight and although according to food consumption than the second group was in a same level but in point of quality has caused a statistically significant (P < 0.05). Thus with adding whey to egg mash of laying fowls can compensate some damage in reduction of egg production due to cold stress.

An experiment was conducted to evaluate the effects of inorganic and organic trace minerals sources (Zn، Cu، Mn، Fe، Se) on performance، egg quality and egg trace minerals concentrations of laying hens. Ninety 34-wk of age Lohmann LSL hens were used in completely randomized block design with 3 experimental groups and 3 replicates in each group with 10 hens in each replicate. The experimental diets were fed included: control (without inorganic and organic trace minerals); control with 0. 25% inorganic trace minerals and control with 0. 1% organic trace minerals. The hens performance، egg quality and egg trace minerals concentrations were evaluated in 28-d period. The results showed that the use of inorganic and organic trace minerals sources could not affected the production، egg quality and egg trace minerals concentrations (p>0. 05).

The present study was carried out to investigate the effects of different levels of canola meal eithr with or without phytase addition on laying hen's performance. A number of 288 layer hens (the strains of Hy-line W36) at the 60th week of age, selected as based on the same egg production percentage and body weight were, assigned to a factorial arrangement with a completely randomized design of 18 treatments (each treatment in 4 replicates). The factors included 6 levels of canola meal replacements (0, 20, 40, 60, 80 and 100%) and 3 methods of enzyme addition namely: 1-without enzyme 2-with enzyme (rations balanced with nutrient’s derived from the enzyme accounted for in feed formulation and 3-with enzyme and derived nutrients from the enzyme not taken into account in formulating the ration. The experiment was performed in three 28 day periods. The results indicated that feed intake was not affected by canola meal and enzyme and it was not affected by the interaction between enzyme and canola meal either. Phytase and canola meal addition to layer diet had no significant effect on mass egg production. Egg weight was affected by different levels of canola meal (P<0.01). The effect of interaction between phytase supplementation and canola meal in diet was significant on egg weight (P<0.05). Egg mass didn’t affect by canola meal, phytase and their interaction (P>0.05).There were no significant effects of different levels of canola, enzyme and their interaction on body weight changes, soft and cracked shell egg percentage and FCR (P>0.05). The effect of canola meal and phytase on toe ash as well as its Ca and P content was significant (P<0.01).