سطوح مختلف والین در جیره های غذایی کم پروتئین، بر سیستم ایمنی طیور موثر می باشد. مطالعه حاضر، به منظور ارزیابی تأثیر مقادیر مختلف اسیدآمینه مذکور در جیره های غذایی کم پروتئین بر پاسخ سیستم ایمنی جوجه های گوشتی انجام شد. بدین منظور از 200 قطعه جوجه گوشتی نر سویه راس 308 در قالب طرح کاملاً تصادفی، به صورت 5 تکرار و 10 پرنده در هر تکرار، استفاده گردید. تیمارهای آزمایشی بر اساس جداول برزیلی تنظیم شدند که شامل: جیره شاهد،مقدار توصیه شده والین، 10 درصد بیشتر از میزان توصیه شده والین و 20درصد بیشتر از مقدار توصیه شده والین که در جیره حاوی 2 درصد پروتئین، رقیق شده بودند. نتایج نشان داد که مقادیر مختلف والین تأثیر معنی داری بر وزن کبد، طحال و بورس فابریسیوس نداشت(05/0<p). همچنین افزودن اسیدآمینه والین تأثیر معنی داری بر لکوسیت ها نشان نداد (05/0<p). اما مصرف جیره حاوی 20 درصد والین به طور معنی داری باعث افزایش عیار پادتن در آزمایش HI (haemagglutination inhibition test) و ایمنی هومورال گردید (05/0>p). همچنین پاسخ اولیه پادتن کل تحت تأثیر تیمارهای آزمایشی قرار نگرفت (05/0<p)، اما سطح 20 درصد والین، باعث افزایش پاسخ ثانویه کل و مقدار IgM علیه گلبولقرمزگوسفندی شد (05/0>p). ازطرف دیگر، افزودن اسید آمینه والین تأثیر معنی‌داری بر واکنش تزریق فیتوهماگلوتینین داشت و سطح 20 درصد آن نسبت به مقدار آن در تیمار شاهد و سطوح پایین تر استفاده شده، به طور معنی داری باعث افزایش ایمنی سلولی جوجه های گوشتی شد(05/0>p). در مطالعه حاضر افزودن سطوح بالای اسیدآمینه والین در جیره های کم پروتئین، باعث بهبود سیستم ایمنی سلولی و همورال جوجه های گوشتی گردید. تفاصيل المقالة

این مطالعه برای ارزیابی اثرات تجویز اسیدفولیک و متیونین بر محتوای 5-متیل تتراهیدروفولات و عنصر روی زرده تخم مرغ و میزان روی و هموسیستئین سرم خون مرغان تخمگذار لگهورن سویه ‌های-لاین W36 از سن 20 تا 26 هفتگی صورت گرفت. جیره های آزمایشی در قالب طرح کاملاً تصادفی به روش فاکتوریل 4×4 با 4 سطح متیونین (25/0، 32/0، 42/0 و 48/0 درصد جیره) و 4 سطح اسید فولیک (0، 5، 10 و 15 میلی گرم در کیلوگرم جیره) تنظیم شد. مکمل سازی جیره مرغان تخمگذار با اسید فولیک در سطوح 0، 5، 10 و 15 میلی گرم در کیلوگرم جیره باعث افزایش معنی دار میزان 5-متیل تتراهیدروفولات زرده تخم مرغ شد (05/0p<). همچنین، سطح 5-متیل تتراهیدروفولات زرده به طور معنی داری تحت تاثیر اثر متقابل متیونین و اسیدفولیک جیره قرار گرفت (05/0p<). میزان هموسیستئین و عنصر روی سرم خون و عنصر روی زرده با افزایش سطح اسیدفولیک به طور معنی داری کاهش یافت، ولی متیونین جیره بر سطح روی زرده تاثیر نداشت. اسید فولیک (5، 10 و 15 میلی گرم در کیلوگرم جیره) و متیونین (32/0، 42/0 و 48/0 درصد جیره) افزوده شده در جیره مرغ های تخمگذار باعث افزایش محتوای فولات تخم مرغ به شکل 5-متیل تتراهیدروفولات می شود. تفاصيل المقالة

Two experiments were conducted to determine: first, the best time of excreta collection after force feeding of broilers to yield the maximal amount of excreta, and second, nitrogen-corrected true metabolizable energy contents of some poultry feedstuffs including yellow corn, soybean meal, corn gluten meal, canola meal and poultry by-product meal by a new precision-fed chick assay using 3-week-old broiler chicks. In experiment one, thirty-five 21-d-old male broiler chicks, with the same body weight were randomly assigned in to 7 experimental groups with 5 birds per each. Seven experimental treatments were designed with different excreta collection times. All chicks were precision-fed with 10 g of corn-soybean meal (60:40) mixture. Excreta were collected at 2, 4, 6, 8, 10, 12, and 14 h after precision feeding. In experiment two, thirty 21-d old male broiler chicks with 5 chicks per each feed ingredients were precision-fed by 10 g of experimental feedstuffs and 5 chicks fasted for determining endogenous energy losses. The maximum time of excreta collection for 3-week-old male broiler chicks was approximately 12 h after precision feeding. The average nitrogen-corrected true metabolizable energy values of yellow corn, soybean meal, corn gluten meal, canola meal and poultry by-product meal, were 3527.55, 2572.4, 4183.25, 1806.38 and 2678.06 kcal/kg, respectively. In conclusion, nitrogen-corrected true metabolizable energy values of feedstuffs can be determined in 3-week-old broiler chicks by using a precision-fed assay. This research suggests using energy values obtained on young broiler chicks in formulating diets for the same birds. تفاصيل المقالة

Zinc (Zn) supplementation of food can be used in broilers to overcome Zn deficiencies in human and also to improve the growth rate and immune system of birds. Due to the lack of information about the impact of Zn nanoparticles (Zn-NPs) on meat quality, this study was conducted to evaluate the differences between dietary Zn-NPs and other Zn sources on broiler performance, carcass characteristics, humoral immunity, meat quality, meat Zn content, as well as fresh and frozen meat oxidative values. Day-old broiler chicks (Ross 308, n=240) were randomly divided into six dietary treatments with four replicates, based on a completely randomized design (d 1-42). Dietary treatments composed of different Zn sources supplemented per kg of basal diet (30 mg/kg Zn) included: control (70 mg from ZnSO4), 70ZAAC (70 mg from Zn amino acid complex), 30BZMO (30 mg Zn from Zn-NPs), 50BZMO (50 mg Zn from Zn-NPs), 70BZMO (70 mg Zn from Zn-NPs), and 90BZMO (90 mg Zn from Zn-NPs). Results showed a higher amount of IgM in chickens fed with Zn-NPs and 70ZAAC, though no effect was found on performance, carcass characteristics, and also the relative weight of lymphatic organs. Breast meat shear force, redness and lightness indexes, malondialdehyde (MDA) content, and Zn content were significantly affected by experimental diets, though no effect of treatments was observed on MDA and Zn content of thigh muscle. Lower pH value of breast meat was found in chickens fed with Zn-NPs and 70ZAAC. The present results showed that 30BZMO, as a recommended Zn-NPs treatment, supported growth performance, improved humoral immunity, Zn content of breast meat, and meat quality, while decreasing MDA content of breast meat. تفاصيل المقالة

The objective of this study was to estimate the optimum requirement of the digestible leucine in ratio to lysine in female Cobb 500 broiler chicks from 8-14 days of age. In this study, 540 female broiler chickens (Cobb 500), were allocated to the experimental units in a completely randomized design with 6 treatments of 6 replicate pens of 15 birds in each. A basal diet (2890 kcal apparent metabolizable energy corrected for nitrogen (AMEn)/kg; 19% crude protein) was formulated to provide all of the nutrients with the exception of leucine. Lysine was sub-limiting and provided at 90% of recommended level of digestible lysine. Crystalline L-glutamic acid in basal diet was replaced by crystalline L-leucine to provide experimental diets containing 0.93, 0.98, 1.03, 1.08, 1.13, and 1.18 digestible leucine in ratio to lysine. Performance parameters were evaluated during a 7-day period (d 8-14) of ad libitum feeding. The body weight, weight gain and feed intake were significantly influenced by dietary treatments and showed quadratic effect with increasing digestible leucine in ratio to lysine. The groups fed 1.03 and 1.13 digestible leucine in ratio to lysine diet had statistically (p <0.05) greater feed intake than the group fed 0.93 digestible leucine in ratio to lysine diet. The birds fed 1.13 digestible leucine in ratio to lysine diet had higher body weight and weight gain (p <0.05) than the birds fed 0.93 digestible leucine in ratio to lysine diet. Using the curvilinear-plateau model and the quadratic regression analyses, the requirement of digestible leucine to lysine ratio for maximum feed intake were estimated as 1.05 and 1.04, respectively. The curvilinear-plateau model and the quadratic regression analyses estimated the requirement of digestible leucine to lysine ratio for maximum weight gain to be 1.07 and 1.06, respectively. However, the curvilinear-plateau model estimated the requirement of digestible leucine to lysine ratio for the minimum feed conversion ratio at 1.11. Based on the analysis of obtained data, female Cobb 500 broilers need lower ratio of leucine to optimize feed intake and weight gain than feed conversion ratio. In conclusion, the requirement of Cobb 500 female broilers from 8 to 14 d of age to support performance parameters was 1.08 digestible leucine in ratio to lysine. تفاصيل المقالة

Three experiments wereconducted to evaluate chemical characteristics, intestinal absorption and bioavailability of manganese(Mn)from organic, inorganic and nano sources of Mn. In experiment 1, inorganic sources of Mn including Mn-sulphate and Mn-oxide, organic sources of Mn as Mn-glycinate and Mn-bioplex and FRA® easy dry Mn as a nano source of Mn were subjected to elemental analysis and solubility in deionized water, 0.4% hydrochloric acid, 2% citric acid and neutral ammonium citrate. In the experiment 2, intestinal absorption of Mn from these sources was investigated by in vitro everted gut sacs technique in broiler chicks. In the experiment 3, the bioavailability of Mn-sulphate, Mn-Glycinate and FRA® easy dry Mn was determined in chicks fed a corn-soybean meal-basal diet that was supplemented with 0, 40, 100, and 160 mg of Mn from these sources per kg of diet based on body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) for 21 days from d 7 to 28. The results showed Mn-sulfate dissolved completely in all solvents. The solubility of all Mn sources was the lowest and the highest in deionized water and neutral ammonium citrate, respectively. The uptake percentages of Mn as nano Mn and Mn-oxide were significantly the highest and the lowest by duodenal and jejunal sacs, respectively. Mn as either Mn-Glycinate or nano Mn was absorbed more efficiently than Mn from other sources by ileal sacs. Amoung organic and inorganic sources, Mn-Glycinate and Mn-sulfate had the higher Mn absorption, respectively. BWG, FI and FCR did not affect by either Mn level or source. We concluded that ileum was the main site of Mn absorption for broilers and among different Mn sources, Mn-Glycinate and nano Mn had the highest Mn absorption. Furthermore, growth was not appropriate criteria to assess bioavailability of different Mn sources. تفاصيل المقالة

To determine chemical composition as well as apparent metabolizable energy corrected to zero nitrogen balance (AMEn) estimates of Amaranth grain in adult roosters by regression method, firstly, a specie of Amaranthus hybridus chorostachys were cultivated in a farm pilot at agriculture research station (Khalat Poushan-Tabriz- East Azarbaijan- Iran). After harvesting, amaranth grain was sifted and milled. Finally, the chemical composition of amaranth grain produced in the Advanced Animal Nutrition Laboratory was analyzed. Adult roosters 96-week-old Leghorn in individual metabolic cages for nine daysused to determine AMEn content by the regression method. The basal diet was based on corn-soybean with 3200 kcal/kg metabolizable energy and 12% protein. Two experiments with raw amaranth grain (RAG) and processing amaranth grain (PAG), started separately using 40 leghorn roosters in the form of completely random by factorial method (2´5), that each experiment consisted oftwo levels of Rovabio multi-enzyme (0 and 0.055%) and five amaranth grain levels (0, 15, 30, 45, 60% of replacement or embedment of energizing part of the diet). Each experiment included four replicates that included one bird, it was subjected to biological experiments in metabolic cages by total excreta collection method. The obtained results of regression equations in adult roosters showed that AMEn content for raw amaranth without enzyme (RAG-e), raw amaranth with an enzyme (RAG+e), processed amaranth without enzyme (PAG-e), and processed amaranth with an enzyme (PAG+e) were 3250.24, 3433.18, 3242.18 and 3438.09 kcal/kg, respectively. The total results of this study showed that according to amaranth's adaptable and nutritious agricultural features, it can have a good potential in supplementation of poultry diets with enzymes for improving the energy and nutrition quality. تفاصيل المقالة