فهرست مطالب r. kianfar

Vitamin D3 is one of the important vitamins in calcium metabolism, which is significantly involved in the absorption of calcium from the intestine. The main role of 1, 25-hydroxyvitamin D3 in vertebrates is to regulate calcium homeostasis, as 1, 25-hydroxyvitamin D3 has a direct effect on the gut, kidney, and bones by inhibiting the production of parathyroid hormone in the parathyroid glands. The synthesis of 1, 25-dihydroxycholecalciferol is tightly controlled, and the main stimulus for its synthesis is the reduction in plasma calcium. This is a feedback stimulus for the release of parathyroid hormone from the parathyroid gland. This hormone in turn stimulates the 1-hydroxylase enzyme complex in the kidney and causes the conversion of 25-hydroxycholecalciferol through the synthesis of calcium-binding protein in the duodenum, thereby increasing dietary calcium absorption and ultimately plasma calcium. Another powerful factor in calcium absorption is organic acids. By lowering the pH of the digestive tract, organic acids (lactic acid) prevent the formation of an insoluble complex of phytic acid with minerals, making phytate more sensitive to the action of endogenous phytase and preventing it from interfering with the absorption of minerals. Therefore, the purpose of this research was to study the effect of vitamin D3 and lactic acid on performance, egg quality, and hatchability in broiler breeders. A total of 240 broiler breeder hens and 24 roosters of Ross 308 strain were used in a completely randomized design with a 2×2 factorial arrangement including two levels of vitamin D (3500 and 5500 IU) and two levels of organic acid (zero and 500 mg/kg) in four treatments, six replications, and 10 hens and one rooster per replication. During the experiment, the percentage of hatchability, the number, and weight of eggs produced by each pen were recorded and using the common formulas of egg mass (as the percentage of laying multiplied by the average egg weight), the percentage of egg production as chicken-day and the feed conversion factor (as grams of feed consumed per gram of egg), the amount of feed used to produce each number of eggs and each piece of chicken, as well as the number of chickens produced per chicken was also calculated. Egg characteristics (egg weight and shape index) and egg shell quality (egg specific weight, eggshell weight compared to total egg weight and eggshell thickness), albumen and yolk pH, yolk index, Haugh unit, yolk color, percentage albumen and yolk percentage of four eggs from each replicate were measured every 28 days. The specific weight of the eggs was determined using the flotation method. The egg shape index was determined by measuring the width and length of the egg with a caliper to calculate the ratio of width to length. To determine eggshell parameters, eggs were identified and broken individually. Eggshells were washed under running water and dried at 35 °C for 72 hours. Then the eggshells were weighed and their relative weight was calculated. A digital micrometer (Series 500, Mitoyota, Tokyo, Japan) was used to measure the shell thickness. Results showed that the main effect of vitamin D3 at higher concentrations was affecting egg weight and reducing egg weight (P<0.05). The main effect of vitamin D3 at higher concentrations caused an increase in albumen pH, shell percentage, shell thickness, and specific gravity of the egg, and a decrease in yolk pH (P<0.05). Probably, with the increase in vitamin D3, the concentration of 1,25-cholecalciferol and the amount of calcium absorption increase, and since most of the shell is related to calcium carbonate, this leads to an increase in the thickness of the eggshell. The main effect of lactic acid showed a significant effect on performance parameters, and the addition of lactic acid improved performance (P<0.05). Lactic acid also significantly increased hatchability and shell thickness and reduced the number of broken eggs (P<0.05). It appears that organic acids increase the solubility of wheat phytates during germination. Therefore, acidification of the diet provides a better environment for phytase to reduce the amount of phytate present in digestion and flowing into the small intestine, thereby largely preventing the formation of insoluble mineral-phytate complexes and increasing the quality of the eggshell. Also, the main effect of lactic acid showed no significant influence on the internal quality of the eggs. The low levels of vitamin D3 and the addition of lactic acid improved shell thickness and reduced the percentage of shell breakage (P<0.05). In general, according to the results of the present experiment, the use of lactic acid at the rate of 500 mg/kg along with 3500 IU of vitamin D3 can increase the percentage of production, shell thickness, reduce the number of broken eggs, improve the feed conversion ratio, increase chicken production and reduce feed consumption per egg and chicken at the end of the production period of broiler breeder hens.

Food additives are a group of different substances that are used for different purposes in poultry diets. Antibiotics are a group of food additives that have been used for many years in the poultry industry to improve performance. Numerous studies have shown that the use of antibiotics in poultry diets, although slightly improved performance; however, long-term use of antibiotics causes bacterial resistance and endangers human health. Therefore, today, due to the limitations of the use of antibiotics, the use of natural alternatives such as medicinal plants has been considered. Medicinal plants as a natural feed additive in poultry diets have been effective in improving performance, improving the immune response, maintaining bird health, and reducing the effects of oxidative spoilage. Turmeric is one of the medicinal plants used in poultry diets. Turmeric, due to its curcumin, can improve the antioxidant and immune status of poultry. Another medicinal plant is red pepper. Red pepper has been suggested as a beneficial factor due to its active ingredients such as capsaicin, vitamins A, E, C, and B, minerals, and carotenoids. Red pepper is effective on the immune system of poultry. Therefore, an experiment was conducted to investigate the effect of adding turmeric powder and red pepper in corn-based diets on the performance of growing quails.

The experiment was performed for 35 days using 512 day-old Japanese quails (as hatched), in a completely randomized design with eight treatments (three levels of turmeric (0.75, 1.5, and 2.25 %), three levels of red pepper powder (0.75, 1.5, and 2.25 %), an antibiotic treatment (500 ppm) and a control treatment without additive with four replicates and 16 birds in each replicate. Nutritional requirements of quails were extracted from NRC. Live weight and feed intake were measured weekly. To calculate the feed conversion ratio, first, the amounts of feed intake and daily weight gain during the experimental period were determined, and then the value of the feed conversion ratio was calculated by dividing the feed intake by weight gain. At 35 days of age, two male and two female birds from each treatment were numbered and slaughtered and carcass weight, thigh weight, and chest weight were measured. Carcass yield was then calculated by dividing carcass weight to live weight. Evaluation of the immune system of quails was assessed by measuring the weight of the thymus gland and bursa of Fabricius and blood immunoglobulin in terms of antibodies produced against Newcastle virus (HI test).

The results of this experiment showed that at the age of 35 days, quails receiving experimental diets had a higher live weight than the control group (P<0.05). The effect of treatments on feed intake was significant (P<0.05). Adding turmeric and red pepper throughout the experiment reduced feed intake compared with the control group. FCR was significantly affected by experimental diets during the whole experiment period (P<0.01), and quails received 0.75% turmeric powder (2.18) and quails received 1.50% turmeric powder (2.16) had a significantly lower FCR than the control treatment (2.69). Contrary to red pepper, adding turmeric powder improved the FCR of quails (P<0.01). Curcumin in turmeric has a positive effect on bile production, secretion of gastrointestinal enzymes (amylase and lipase), increases the length of intestinal villi, and increases digestion and absorption of nutrients in birds. Some studies have reported the effectiveness of red pepper on digestive enzymes, and performance has been improved in various species. Capsaicin (the main active ingredient in red pepper) has increased the activity of amylase, lipase, and trypsin enzymes in the duodenum. The levels of triglycerides, cholesterol, LDL and HDL, VLDL, and total serum antioxidants (TAC) significantly affected experimental diets (P<0.05). The triglycerides of quails received 2.25% red pepper powder (152 mg/dL) was lower than the control group (261 mg/dL). The reason for lowering blood triglycerides would be the presence of capsaicin in red pepper, which reduces the activity of glycerol 3-phosphate dehydrogenase and malate dehydrogenase, thereby reducing fat synthesis.

Based on the results of the present study, feeding 1.5 % turmeric powder or 2.25% chili pepper powder is recommended to improve the performance, blood parameters, and immune response of growing quails.

Viral fusion protein through protected areas called fusion peptide are essential for entry of the virus into the host cell by membrane integration. Fusion phenomenon occurs at the host cell surface or in the cytoplasmic compounds and in cytoplasmic components. The fusion proteins are divided into three categories according to variations that are likely during the fusion. In the first category, which includes viruses such as orthomixo, paramyxo, filo, corona, and retroviruses, definite domains of fusion proteins are cleaved and removed and they become mature and functional. The second group of fusion proteins is alpha and flaviviruses become their functional form without cleavage. The third category also includes viruses such as vesicular stomatitis, herpes simplex, and baculovirus, they have common features of the first and second categories.The changes in fusion protein in the levels before and after fusion, description of fusion proteins in viruses such as influenza, filo, and reoviruses as a prototype of fusion protein viruses and their therapeutic applications of fusion protein as potential drugs such as Lactoferrin and Enfuvertide in preventing the occurrence of fusion phenomenon is an important issue for consideration about multiplication and virus entry.

 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.

CLA is a mixture of several geometrical and positional conjugated isomers of linoleic acid (C 18:2 cis-9, cis-12). Ruminant products, such as milk, meat, and cheese, are major CLA sources in human diets, but foods obtained from non-ruminants, contain much less CLA. Some reports showed positive effects of CLA on production performance of layer hens. Egg internal quality traits may be depressed during storage, but incorporation of CLA, may increase the permeability of the yolk membrane due to the cis-trans arrangements of CLA, therefore ion movement between the yolks and albumen through the yolk membrane, restrict some changes in egg internal quality traits, therefore an experiment was conducted to evaluate the effects of different levels of CLA in post-molting phase of laying hens on production performance and egg quality in different storage times and temperatures.
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. During the experiment, hens were provided feed and water ad-libitum. Egg production, egg weight, feed consumption, egg mass and feed conversion ratio were recorded weekly and reported as total period. Every two weeks, internal and external quality traits such as albumen percent, yolk percent, albumen pH, yolk pH, Haugh unit, yolk height, yolk Roche scale, yolk index, egg size, egg surface, specific gravity, shell strength, shell percent and thickness were evaluated. The eggs from treatments having best production performance (0.5 %) collected and stored in different temperatures (4 and 27° C) and duration times (1 day, 1 week and 1 month after production) then evaluated their internal quality. Results showed that egg production performance and egg mass of birds fed 0.5 % CLA was significantly higher than control or those fed 0.25 % during whole experimental period, but egg weight and feed consumption were not affected significantly by dietary CLA level and feed conversion ratio of birds fed 0.5 % CLA was significantly (P<0.05) lower than control or those fed 0.25 %. In the end of experiment, the internal egg quality traits such as albumen percent, yolk percent, albumen pH, yolk pH, Haugh unit, yolk height, yolk Roche scale, yolk index were not affected by dietary CLA levels (P>0.05). Also the external egg quality traits such as egg size, egg surface, specific gravity, shell strength, shell percent and thickness were not affected significantly. Results of egg quality traits during different times and temperatures showed that main effects of CLA levels, storage times and storage temperatures were significant (P<0.05) on most important egg internal quality traits such as Haugh unit and pH of albumen. Interaction effects of CLA levels with storage times and temperatures were significant (P<0.05) and in eggs kept within higher temperatures and longer times, albumen pH of eggs for birds fed 0.5 % CLA, were lower compared to albumen pH of eggs for birds fed control diet containing 0 % CLA. These results indicate that ion movement between the yolks and albumen through the yolk membrane in eggs from hens fed 0.5 % CLA was greater than that in the control eggs and caused to restrict pH increase during storage. It is speculated that the incorporation of CLA, most of which was in the trans form, could have increased the permeability of yolk membrane because of the cis-trans arrangements of CLA, which would have increased membrane fluidity and sizes of space between the fatty acid chains of phospholipids that constitute the membrane bilayer. It is concluded that use of 0.5 % CLA in post-molting diet of laying hens improved egg production performance of birds and restricted luctuations in pH and Haugh unit changes of eggs keep during high storage temperatures and duration times, therefore it is suggested to adding 0.5 % pure CLA in post-molted laying hen diets.

This study was performed to evaluate   the effects of folic acid (FA) and methionine (Mt) administration on egg 5-methyltetrahydrofolate (5-MTHF) content, levels of zinc in yolk and serum and concentration of homocysteine on Hy-line W36 hens from 20 to 26 weeks of age. The experiment was conducted as a 4×4 factorial arrangement of treatments in randomized complete design with four levels of Mt (0.25, 0.32, 042, 0.48 mg/kg of diet) and four levels of FA (0, 5, 10, 15 mg/kg of diet). Fortification of laying hens diets with FA 0, 5, 10 and15 mg/kg of diet increased 5-MTHF into yolk significantly (p<0.05). 5-MTHF content of egg was also significantly affected by FA×Mt interaction (p<0.05). FA significantly reduced Zn level of egg and serum (p<0.05), but Mt did not have any effect on Zn content in egg. Levels of serum homocysteine were significantly reduced by fortification of diet by FA (p<0.05).Supplementation of laying poultry diet with FA and Mt could improve the content of yolk 5-MTHF.