فهرست مطالب
فصلنامه پژوهشهای تولیدات دامی
پیاپی 15 (بهار 1396)
- تاریخ انتشار: 1396/04/12
- تعداد عناوین: 26
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صفحات 1-10در این آزمایش ترکیب مواد معدنی، محلولیت آزمایشگاهی هفت منبع کربنات کلسیم و اثرات تغذیه آن بر عملکرد، و قابلیت هضم کلسیم و فسفر جوجه های گوشتی مورد ارزیابی قرار گرفت. آزمایش به صورت فاکتوریل 6×2 در قالب طرح کاملا تصادفی با 12 جیره حاوی شش منبع کربنات کلسیم و دو سطح از اندازه ذرات (5/0>، 83/2 > و 41/1<) و یک جیره به عنوان گروه شاهد (حاوی پوسته صدف با اندازه ذرات 5/0>) انجام گرفت. در کل 486 قطعه جوجه گوشتی به 13 جیره آزمایشی با سه قفس (18 پرنده در هر قفس) به ازای هر تیمار از روز اول پس از هچ اختصاص داده شد. هفت منبع کلسیمی (شش منبع کربنات کلسیم و صدف) به سه حدود از اندازه ذرات 5/0>، 83/2 >- 41/1< ، 83/2< میلی متر جدا شدند. متوسط غلظت کلسیم در منابع کلسیمی 08/36 گرم بر کیلوگرم بود. محلولیت آزمایشگاهی وابسته به منبع کلسیمی و اندازه ذرات بود به طوری که ذرات کوچکتر در زمان یکسان نسبت به ذرات بزرگتر محلولیت آزمایشگاهی بیشتری داشتند. منابع مختلف کلسیمی در دوره آغازین تاثیر معنی داری بر افزایش وزن و خوراک مصرفی داشتند (05/0>p) ولی در دوره رشد تاثیر معنی داری بر صفات عملکرد نشان ندادند. قابلیت هضم ظاهری کلسیم و فسفر در منابع کلسیمی با اندازه ذرات کوچکتر از 5/0 در مقایسه با ذرات بزرگ بیشتر بود (05/0>p). خاکستر، ماده خشک غیرچربی، کلسیم و فسفر استخوان درشت نی تحت تاثیر منابع کلسیمی قرار نگرفت. در نتیجه، آزمایش حاضر نشان داد که عملکرد و صفات استخوانی جوجه های گوشتی توسط منبع کلسیمی و اندازه ذرات تحت تاثیر واقع نمی شود و تفاوت در قابلیت هضم کلسیم و فسفر و محلولیت آزمایشگاهی وابسته به اندازه ذرات و منبع کلسیمی متفاوت بود.کلیدواژگان: کربنات کلسیم، محلولیت آزمایشگاهی، قابلیت هضم، استخوان، جوجه گوشتی
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صفحات 11-17در این تحقیق، اثر سطوح مختلف انرژی قابل متابولیسم و پروتئین خام جیره غذایی بر عملکرد، خصوصیات لاشه و فراسنجه های خونی بلدرچین ژاپنی در دوره رشد (14 تا 28 روزگی) بررسی شد. از 900 قطعه بلدرچین ژاپنی نر 14 روزه در یک آزمایش فاکتوریل 3×3 [سه سطح انرژی قابل متابولیسم (2900، 3050 و 3200 کیلوکالری در کیلوگرم) و سه سطح پروتئین خام (6/21، 24 و 4/26 درصد)] به صورت طرح کاملا تصادفی با پنج تکرار و 20 پرنده در هر تکرار استفاده شد. مصرف خوراک، افزایش وزن و ضریب تبدیل خوراک در کل دوره اندازه گیری شد. در پایان دوره، از هر تکرار دو قطعه پرنده انتخاب و پس از خون گیری (برای اندازه گیری تری گلیسرید، کلسترول کل، ldl و اسید اوریک) جهت بررسی خصوصیات لاشه کشتار شدند.
پایین ترین و بالاترین سطح انرژی و پروتئین، به ترتیب بیش ترین مصرف خوراک روزانه را موجب شدند (05/0p<). افزایش وزن روزانه تحت تاثیر تیمارها قرار نگرفت (05/0کلیدواژگان: انرژی قابل متابولیسم، پروتئین خام، عملکرد، فراسنجه های خونی، بلدرچین ژاپنی، دوره رشد
p). آفلاتوکسین به طور معنی داری آنزیم های سرمی آلانین آمینوترانسفراز و آسپارتات آمینوترانسفراز را افزایش داد ولی عصاره آبی آویشن به طور معنی داری آنزیم های سرمی آلانین آمینوترانسفراز و آسپارتات آمینوترانسفراز را کاهش داد. اثر متقابل معنی داری بین آفلاتوکسین و عصاره آبی آویشن وجود داشت به طوری که افزودن عصاره آبی آویشن به جیره حاوی آفلاتوکسین به طور معنی داری آنزیم های سرمی آلانین آمینوترانسفراز و آسپارتات آمینوترانسفراز را کاهش داد (05/0>p). بنابراین نتایج نشان داد افزودن عصاره آبی آویشن دنایی باعث کاهش اثرات نامطلوب ایجاد شده به وسیله آفلاتوکسین در جیره بلدرچین ژاپنی می شود.
(05/0P <). در مرحله دوم تعداد 120 قطعه جوجه یک روزه بلدرچین ژاپنی در قالب طرح کاملا تصادفی با 4 تیمار، 5 تکرار و 6 جوجه در هر قفس مورد استفاده قرار گرفت. گروه های آزمایشی شامل 1- شاهد منفی، تغذیه با دان غیرآلوده، 2- شاهد مثبت – تغذیه با دان آلوده به دو پی پی ام آفلاتوکسین B1، 3- دان آلوده + آب آشامیدنی حاوی 4/0 درصد زرده دارای IgY ضد آفلاتوکسین B1، 4- دان آلوده + آب آشامیدنی حاوی 4/0 درصد زرده ایمن نشده علیه AFB1 بودند. مصرف جیره آلوده موجب کاهش معنی دار پروتئین تام، آلبومین، HDL، تری گلیسرید، کلسترول و گلوکز سرم شد. تنها میزان کراتینین سرم در پرندگان گروه شاهد مثبت افزایش نشان داد (05/0p <). مصرف زرده ایمن از ایجاد این تغییرات جلوگیری نمود. پاسخ های ایمنی سلولی و همورال پرندگان تحت تاثیر مصرف جیره آلوده کاهش یافت و مصرف زرده ایمن و غیرایمن این تاثیر منفی را تا حد مشابه با گروه شاهد منفی بهبود داد (05/0p <).
سال های 1383 تا 1388 استفاده شد. برای توصیف منحنی رشد از چهار مدل رگرسیون غیرخطی برودی، ون برتالانفی، گومپرتز و لجستیک استفاده گردید. تجزیه و تحلیل های آماری با رویه مدل غیرخطی انجام شد. بهترین مدل با معیارهای ضریب تبیین، جذر میانگین مربعات خطا و میانگین قدرمطلق خطا (تفاوت مقدار پیش بینی شده از مقدار واقعی) تعیین گردید. نتایج تحقیق حاضر برای بره های نر نشان داد که مدل برودی با ضریب تبیین 42/90 درصد، جذر میانگین مربعات خطای 35/8 و میانگین قدر مطلق خطا 65/5 بهترین مدل نسبت به سایر مدل ها بود. برای توصیف منحنی رشد بره های ماده، مدل ون برتالانفی با ضریب تبیین 85/96 درصد، جذر میانگین مربعات خطا 54/4 و میانگین قدر مطلق خطا 16/3 مدل بهتر نسبت به سایر مدل ها تعیین شد. هم بستگی بین پارامترهای وزن بلوغ ونرخ بلوغ برای مدل های ون برتالانفی، برودی، گومپرتزولجستیک به ترتیب 36/0- ، 54/0-، 30/0- و 21/0- برآورد شد.
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Pages 1-10Mineral composition and in vitro solubility rates for seven different Calcium (Ca) sources, and their feeding effects on performance and digestibility of calcium and phosphorous in broiler chickens were assessed. The experiment used a 6 × 2 factorial arrangement with 12 diets formulated to contain of 6 Ca sources and 2 levels of particle size ( 1.0-2.0 mm) and one diet as a control contain oyster shell ( 1.41-2.83 mm, and >2.83 mm. Average concentration of Ca was 36.2 g/kg in all Ca sources. In vitro solubility was dependent upon Ca source and particle size with small particle generally having a greater in vitro solubility than large particle at the same time. Dietary treatments had effect on the feed intake and body weight gain in starter period, but there was no difference in performance of different Ca sources and different particle in grower period in broiler chickens. Apparent Ca and P digestibility in Ca sources was greater (P 0.5 mm compared with those fed higher particle size. However, the bone ash, non-fat dry matter, Ca and P of were not affected by Ca sources and partile size. In conclusion, results of the present experiment demonstrated that performance and bone traits of broilers were not affected by Ca sources and particle sizes; and there was difference in in vitro solubility and Ca and P digestibility of different Ca sources in broiler chickens.Keywords: Bone, Broiler chickens, Digestibility, In-vitro solubility, Limestone
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Pages 11-17This research was conducted to investigate the effect of different levels of metabolisable energy and crude protein on performance, carcass characteristics and blood parameters of Japanese quail during grower phase (14-28 d of age). Nine hundreds 14-d-old male birds were used to examine 3 levels of energy (2900, 3050 and 3200 Kcal of ME/Kg of the diet) and 3 levels of protein (21.6, 24 and 26.4% CP) by a 3*3 factorial arrangement in a completely randomized design with 5 replicates of 20 birds. Feed intake, weight gain and feed conversion ratio (FCR) were measured during whole period. At the end of the experiment, 2 birds from each replicate were selected to measure the blood parameters (TG, total cholesterol, LDL and uric acid) and carcass characteristics. The lowest and highest levels of energy and protein enhanced (P0.05), however, FCR was improved by the diets of 3050 and 3200 Kcal ME/Kg compared with that of 2900 Kcal ME/Kg. Energy and protein interaction was significant (PKeywords: Blood Parameters, Crude Protein, Grower Phase, Japanese Quail, Metabolisable Energy, Performance
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Pages 18-24An experiment was conducted to determine the effects of different levels of feed intake at 70%, 85% and 100% of the voluntary feed intake on digestibility and rumen microbial protein synthesis. For this purpose, six male lambs (42±1.5 kg BW) were used in a replicated Latin square design (replicated in three periods that were 21 days each). A twenty five days period was assigned as adaptation period before start of the experiment to determine animals voluntary feed intake. Then in experimental period the potential of urinary purine derivatives as a predictive index of microbial protein supply was determined. The data were analyzed using SAS statistical software. The results showed that by decreasing the level of feed intake, the amounts of allantoin, total purine derivations excretion, microbial protein synthesis in the rumen, nitrogen balance and PDC index were decreased (PKeywords: Feed Intake Level, Microbial Protein, Purine Derivatives
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Pages 25-32This study evaluated the efficacy of aqueous extract of Thymus daenensis to ameliorate the adverse effects of aflatoxin B1 (AFB1) in Japanese quail. The experiment was conducted as a 2×2 factorial arrangement in a completely randomized design with two levels of aflatoxin (0 and 500µg/kg) and two levels of aqueous extract of T. daenensis (0 and 2000 mg/kg). Each of the 4 dietary treatments was fed to five replicate cages (4 birds/cage) from 24 to 45 days of age. The results showed that Aflatoxin and extract did not have any effect on the histo-morphology of jejunum of birds (PKeywords: Aflatoxin, Aqueous extract of Thymus daenensis, Japanese quail, Medicinal plants
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Pages 33-41The purpose of this experiment was to compare the effects of calcium, phosphorus, and fennel extract (FE) and vitamin D3 on performance and egg shell quality in post molted Ross broiler breeders from 96 to 102 weeks. Each pen consisted of 10 hens and 1 rooster. This experiment was done in a completely randomize design with seven treatments (different levels of calcium, phosphorus plus fennel extract or vitamin D3) that each treatments assigned to 4 replicates. The addition (50 mg/kg diet) FE had significant affection egg production, egg mass, settable egg, shell quality, relative albumin weight and body weight gain (p0/05), but lower levels of calcium and phosphorus (20%) significantly affect these parameters (pKeywords: Broiler Breeder, Calcium, Fennel Extract, Phosphorus, Vitamin D3
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Pages 42-48Two experiments were carried out to determine the potential of oral yolk derived specific antibody against aflatoxin B1 in Japanese quails. In the first experiment egg yolk derived antibody against aflatoxin B1 was produced in layer quails. The potential of aflatoxin absorbent of the eggs from immunized and non-immunized layers was assayed in vitro. Egg yolk extracts derived from aflatoxin-BSA conjugate immunized layers absorbed more aflatoxin B1 compared to that of non-immunized birds in concentrations over 24 g/l (PKeywords: Aflatoxin B1, Antibody, Egg Yolk, Japanese quail
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Pages 49-57An experiment was conducted to evaluate the effects of wheat and wheat bran diets with and without enzymes on growth performance and digestive characteristics of broilers. A total number of 625 one day old Ross-308 broiler chickens were allocated randomly to 5 treatments with 5 replicates, using a CRD statistical design. Treatments were control, wheat, wheat enzyme and wheat bran and wheat bran enzyme. Traits were growth performance, carcass characteristics, ileal microbial counting and measurement of gut acidity and viscosity. According to the results, effect of different treatments on all experimental traits at starter and finisher periods were significant (PKeywords: Broilers, Carcass Characteristics, Growth Performance, Microbial Population, Wheat, Wheat Bran
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Pages 58-67To investigate the effects of different levels of gamma irradiation on degradation rate of barley and soybean seeds and performance of lambs, this study were done. In the first experiment barley and soybean seeds were irradiated with 2 doses of gamma irradiation and degradation rate were estimated in different incubation times. Results of current study showed that gamma irradiation increased the a fraction and decreased b fraction of barley DM, but a fraction of barley crude protein was decreased and b fraction was increased (P0.05). Weight gain was significantly affected by irradiation treatments. Gamma irradiation with dose of 75 KGy significantly improved feed conversion ratio (P0.05). Regard to the results of current study, 50 KGy gamma irradiation has significant effects on by pass of protein resources and use of starch in the diets. Thus, we can use irradiation to get the better performance in ruminant nutrition.Keywords: Barley seeds, Degradation, Feedlot performance, Gamma irradiation, Soybean seeds
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Pages 68-75The objective of this study was to determine the effects of different levels of garlic powder (GP) in the starter diet on performance, weight and age of weaning, some of blood metabolites, fecal score, structural growth and nutrients digestibility in new-born Holstein calves. Thirty male and femal dairy calves (40.9 ± 1.9 Kg of BW) were randomly assigned in a completely randomized design to the following three groups 1) basal diet without GP (control), 2) basal diet supplemented with 0.5% GP, and 3) basal diet supplemented with 1% GP for a period of 70 d. All calves recived colostrum until d 3 and then were offered 4 kg whole milk/d from d 4 to weaning. Results showed that dry matter intake (DMI) was higher in the calves fed rations containing 0.5 and 1% GP and the calves fed 0.5% GP had the highest gain, average daily gain (ADG) and weight of weaning (PKeywords: Dairy calves, Garlic powder, Performance, digestibility, Starter
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Pages 76-83This study was carried out investigate the effect of slow-release blous on reproductive efficiency, twinning and weaning weight. 306 female Cashmere Raeini goats were selected randomly and divided into eight treatments. Treatments were: 1and 2) control with and without injection eCG, 3 and 4) Consumption one slow-release blolus with and without injection eCG, 5 and 6) Consumption two slow-release boluses with and without injection eCG and7 and 8) Consumption one minerals and vitamin capsules with and without injection eCG. To synchronize estrus, ciders were installed in goats and eCG hormone injected in a half of goats. The results showed that reproductive efficiency were reduced with slow-release bolus and capsule supplements. But they had significant effect on twinning (pKeywords: Body condition, Hormone, Live weight
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Pages 84-95The experiment was carried out to evaluate the effect of wheat straw and urea additives on chemical composition, quality characteristics and ruminal degradability parameters of dry matter, neutral detergent insoluble fiber and crude protein orange pulp silage, in a completely randomized design, using nylon bag technique in the form of fore treatments (citrus pulp 1. without additive, 2. with 40% wheat straw, 3. with 38.5% wheat straw and 1.5 % urea, 4. with 37% wheat straw and 3% urea). Results showed that treatment 2 had the highest score on visual assessment of silage. Treatment 1 and 4 had the lowest (3.53) and highest (4.36) pH respectively. Adding wheat straw to orange pulp increased dry matter (DM), ash and neutral detergent fiber (NDF), decreased non fiber carbohydrate (NFC) and ether extract. Urea increased crude protein, pH and NH3-N contents and decreased NFC. Flight point in treatments 1, 2, 3 and 4 were 90.72, 113.64, 94.54 and 82.75, respectively. Treatment 1 had the highest dry matter,s a, b and a. Adding wheat straw and urea significantly decreased dry matter degradability compared to the control treatment. Treatment 2 had the lowest protein,s a and a but adding wheat straw decreased protein degradability. Treatments 1 and 3 and treatment 2 had the highest and lowest NDF,s a respectively, treatment 3 and treatments 1 had the highest and lowest NDF,s b and a therefore additives increased NDF degradability. The results showed that with mixture of orange pulp, wheat straw and urea, can be prepared high quality silage; but through increasing urea more than 1/5 %, for improving the quality of silage soluble carbohydrate source is required. So, with increasing the urea the level of citrus pulp should be increased.Keywords: Chemical Composition, Degradability, Orange Pulp, Urea, Wheat Straw
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Pages 96-104This study was conducted to assess the nutritive value and performance of green fodder (GF) production in hydroponic system. A mixture of barley (100 kg) and corn (80 kg) seeds was prepared and grown in an automatic controlling growing chamber that contained 7 shelevs, each with 16 special trays capacity. From each shelf, 6 trays were taken out after 7, 8, 9 and 10 days (as treatment) and fresh weight was recorded and sampled. Chemical composition and in vitro digestibility was determined. The performance and cost of GF production were estimated. Results showed that the fresh GF yield was 5.25 times of the original seed nevertheless, dry matter obtained was 23.8% less than the initial spent seed. Crude protein (CP) content of GF was significantly higher than that of barley (P=0.0076) and corn grain (P=0.0071) but such elevation in CP was mainly related to non-protein nitrogen. Organic matter digestibility of GF reduced as compared to the barley (P=0.0079) and corn grain (P=0.0087) and ME content. No differences were obtained among the GF treatments for nutrient contents and digestibility.The estimated cost per kg DM, CP, TP and ME obtained from GF were respectively 3.12, 2.01, 3.12 and 3.11 times of barley and corn grains. Ovreall, not only there is a negative balance of nutrients during converting barley and corn grains to green fodder in hydroponic system, but also the price of nutrients obtained by GF is several times higher than the original grains.Keywords: Barley, Corn, Efficiency, Green Fodder, Hydroponic
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Pages 105-114This experiment was conducted to study the effect of different levels of levamisole on performance and related parameters with immune system in Cobb 500 strain male broilers. The experiment was carried out a completely randomized design, with 300 male broiler chickens in four treatments and five replicates 15 birds/replicates. The experimental groups consisted of zero, 2.5, 5 and 7.5 mg per kg live body weight of levamisole in the third week. Parameters examined include performance and related parameters with immune system, phagocytic activity test, antibody titers against Newcastle, Influenza and Gambro disease and organs weight involved in immune system. Results showed that adding of levamisole into diet had no effect on body weight gain, feed intake and feed conversion ratio in broilers. Adding of levamisole into diet increased the number of lymphocytes, monocytes and heterophils in broiler (PKeywords: Blood parameters, Broiler chicks, Immune system, Levamisole, Performance
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Pages 115-123Foot-and-mouth disease (FMD) is an extremely infectious and occasionally fatal viral disease with a rapid onset and a short course that affects cloven-hoofed animals and results in considerable financial losses. For this reason, availability of more reliable and efficient vaccines against Foot-and-mouth disease virus (FMDV) is felt as a necessity. The purpose of this study is to develop a perfectly safe immunogen in order to supplant the usual inactivated vaccine. A tandem repeat multiple-epitope recombinant vaccine against foot-and-mouth disease (FMD) virus (FMDV) type O was developed. In order to develop recombinant epitope vaccines against foot-and-mouth disease virus (FMDV), multiple-epitope recombinant vaccine (rP) comprising various combinations of B cell and T cell epitopes from VP1 capsid protein were synthesized. A 1155-bp gene fragment was amplified by PCR using specific primers. The amplicon was purified and then cloned into expression vector pET-32a. For expression of recombinant protein, pET32a-rP plasmid was transformed into Escherichia coli BL21 (DE3) cells. Recombinant protein was overexpressed with isopropythio-beta-D-galctoside (IPTG). SDSPAGE and DOT blotting were performed for protein determination and verification.The multiple-epitope recombinant was validated by colony-PCR and enzymatic digestion. IPTG with a dosage of 1.0 mmol/L could effectively promote protein expression. SDS-PAGE analysis demonstrated that our constructed prokaryotic expression system pET32a-rP efficiently produces a target recombinant protein with a molecular weight of about 60 kDa. Results showed that prokaryotic expression system is effective in producing the multiple-epitope recombinant immunogen for FDM virus and can be used as a potential method for poly epitope constructs.Keywords: Foot, Mouth Disease, FMDv viruse, Multiple Epitope, Recombinant Vaccine
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Pages 124-130This experiment was conducted to evaluate the effects of different levels of garlic and fenugreek powder on performance and immune response in laying hens. The aim of this experiment was to compare the effects of garlic and fenugreek powder on performance, egg quality and hematological parameters and antibody titer against Newcastle disease of commercial laying hens. The experiment was performed for 12 weeks (from 49 to 61 weeks of age) on 288 laying hens (Bovans strain), in a completely randomized design with 6 treatments, and 4 replicate for each treatment (12 birds/replicate). The results showed that garlic and fenugreek powder had no any effect on feed intake, egg mass, egg production percent, egg weight and feed conversion ratio (p>0.05). The highest percentage of production was resulted by using 1% of garlic powder with 1% fenugreek powder. Dietary garlic and fenugreek powder had no significant effects on egg specific gravity, eggshell weight and eggshell thickness. The effect of garlic and fenugreek powder was significant on Haugh unit. Did not have any significant effects on hematological parameters and antibody titers against Newcastle disease of laying hens. The effect of garlic and fenugreek powder was significant in red blood cells. The lowest percentage of heterophile/lymphocyte, the highest percentage of lymphocyte were resulted by using 1% of garlic powder (p>0.05). The overall results showed that using garlic and fenugreek powder until 1 percent improved the egg quality traits but it did not effect performance, blood parameters and immune response of laying hens.Keywords: Garlic Powder, Fenugreek Powder, Antibody Titer, Performance, Blood Parameters, Laying Hen
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Pages 131-137In order to investigating the effect of exogenous enzymes on growth performance, blood and rumen parametes,18 Brown Swiss male bulls were used in an balanced completely randomized design. The experimental diets were: 1) basal diet (control), 2) basal diet containing 0.50 g enzymatic mixture /kg DM of diet and 3) basal diet containing 0.75g enzymatic mixture /kg DM of diet. The bulls were fed total mixture ration (35 percent corn silage and 65 percent concentrate). Results showed that the experimental diets had no significant effect on dry matter intake, average daily gain and feed conversion ratio (P>0.05), but significant differences were observed in dry matter digestibility of diets (P0.05). The experimental diets containing enzymatic supplement had significantly affect on blood metabolites (glucose, blood urea nitrogen, triglyceride and aspartate transaminase) except for alanine transaminase and rumen liquid NH3-N. Therefore, using of enzymatic supplement did not has positive effects on growing performance in brown Swiss fattening bulls, but enzymatic supplement increased some of serum blood and rumen parameters.Keywords: Blood Parameters, Enzyme Mixture, Fattening Bull, Growth Performance, Rumen Parameters
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Pages 138-143The objective of this study was to investigate effect of different time of GnRH administration and CIDR insert after artificial insemination (AI) on fetus Loss, AI interval and conception rate in Holstein dairy cows. Multiparous high-yield dairy cows (> 30 Kg/d, n= 550) were randomly assigned into five groups. Groups were: 1- GnRH injection on day 5 after AI, 2- GnRH injection on day 11 after AI, 3- GnRH injection on day 13 after AI, 4- GnRH injection on day 5 and 11 after AI and 4- Controlled internal drug release (CIDR) devices were inserted on day 5 after AI and removed on day 14 after AI. Ultrasonography were used for consider ovary status and pregnancy diagnosis at d 32 after AI. Pregnancy was characterized by the presence of an embryo, corpus luteum and fluid in uterus horn. Cows diagnosed pregnant at 32 d were re-examined at 70 d after AI to confirm pregnancy. Pregnancy loss was considered to have occurred when a cow was diagnosed pregnant at 32 d after TAI and not pregnant at 70 d. Results showed percentage of cows that showed estrus at 19-24 d after AI was lowest in G5,11 (20.0 %) cows compared to GnRH injection on day 5 after AI (31.5 %), GnRH injection on day 11 after AI (25.7 %), GnRH injection on day 13 after AI (26.5 %) and CIDR group (32.7 %, P = 0.04). Percentage of cows that did not show estrus until day 34 after AI was lowest in CIDR group (20.6 %, P= 0.01) but there was no difference between other groups (average 42.6 %, P = 0.65). A greater (P = 0.01) percentage of cows that received GnRH injection on day 5 and 11 after AI were pregnant at 32 d (50.0) and 70 d (46.2 %) after AI compared to other groups. Pregnancy loss was lowest in CIDR group (P = 0.04). In conclusion GnRH injection on day 5 and 11 after AI compared to other methods improved pregnancy rates.Keywords: CIDR, Holstein Cow, Fetus Loss, GnRH, Ultrasonography
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Pages 144-148In the current study, two groups of lines Coturnix Japonica Quail that were selected for hig (HW) and low (LW) body weight at the age of 4 weeks for 7 generations were used. HW line after selection for 7 generations was significantly heavier than LW line in the same generation at the age of 28days (pKeywords: Heterosis Effect, Japanese Quail, Reciprocal Effect, Reproductive Traits
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Genomic Evaluation of Threshold Traits with Different Genetic Architecture using Bayesian ApproachesPages 149-154The current study was carried out to evaluate accuracy of some Bayesian methods for genomic breeding values prediction for threshold traits with different types of genetic architecture based on distribution of gene effect and QTL numbers. A genome consisted of 3 chromosomes of 100 CM with 2000 single nucleotide polymorphisms (SNP) was simulated. The QTL numbers were 0.01, 0.05 and 0.1 of total number of SNPs whose effects were simulated by uniform, normal and gamma distributions. The studied threshold traits were either one-threshold (survival) or two-threshold (litter size). Genomic estimated breeding values were predicted by five regression methods including Bayesian Ridge Regression (BRR), Bayes A, Bayes B, Bayes C, and Bayes LASSO. Comparison of prediction accuracy of these methods (correlation between real and estimated breeding value) showed that Bayesian methods are powerful for genomic evaluation and there were no significant differences among them. The proficiency of these methods for one-threshold trait was significantly higher compared to two-threshold trait. Non-significant and irregular variance was observed in accuracy of prediction these methods between different QTL numbers and statistical distributions. Also the results showed that increasing in distance (generation) between reference and target populations will lead to decline in accuracy of prediction due to breakdown of LD between QTL and marker.Keywords: Bayesian methods, Genome, Genetic architecture, Threshold traits
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Pages 155-160The purpose of this study was to describe growth curve in Baluchi sheep by application of nonlinear growth models. The weight records of 1228 and 676 Baluchi male and female lambs for birth weight, one-month, two-month, three-month, four-month, six-month, nine-month and one year of age were studied. These data had been collected by Baluchi Sheep Breeding Center in Mashhad (Abbas Abad) during 2004 to 2009. Brody, Von Bertalanffy, Gompertz and Logistic nonlinear models were fitted to describe the growth curve. The most suitable model was determined by R2, Root MSE, as well as mean absolute error (MAE). For data analysis, NLIN procedures were used. The results of this research for male lambs showed that Brody model with R2 (90.42%), Root MSE (8.35) and mean difference between expected and observed value (MAE) (5.65) was the best model compared with others, this value for proper model (Von Bertalanffy) in female lamb were 96.85% (R2), 4.54 (Root MSE) and 3.16 (mean difference between expected and observed value). The correlation between A and K parameters for Von Bertalanffy, Brody, Gompertz and Logistic were -0.36, -0.54, -0.3 and -0.21, respectively.Keywords: Brody, Gompertz, Logistic, Sheep, Von Bertalanffy
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Pages 161-170MicroRNAs (miRNAs) are small non-coding RNAs that have functional roles in post-transcriptional modification. They regulate gene expression by an RNA interfering pathway through cleavage or inhibition of the translation of target mRNA. Numerous miRNAs have been described for their important functions in developmental processes in numerous animals, but there is limited information about sheep and goat miRNAs. Sheep and goat are ideal model organisms for biological and comparative genomics studies in ruminants. Identification of miRNAs is crucial to understanding their biological mechanism. Computational identification approaches can supplement experimental approaches to quickly identify ncRNAs in novel genomes, chiefly miRNAs that are transcribed under particular conditions in specific cell types. Currently, machine learning approaches have been employed to predict novel miRNAs. In this study, we present a new SVM-based classifier. It demonstrated high accuracy, balanced sensitivity and specificity for the miRNA datasets, thus representing an ideal tool for miRNA identification from transcriptome sequencing data. In this research, we generated an optimized feature subset including 20 features using a support vector machine, and we developed a c # program to compute the features in the training sequences. In this study, an intelligent SVM model with RBF kernel and the SMO learning algorithm was the best classifier for predicting microRNA genes in sheep and goat. Sensitivity and specificity of this model were 88% and 85% respectively. Then, expressed sequence tag (EST) analysis was performed for finding sheep and goat mature miRNAs. Chromosome 1 was scanned for finding miRNA potential region. In sheep 23 miRNA genes and, in goat 15 miRNAs had been discovered by homology searching. Our finding demonstrate that the Sheep and goat miRNA sequences can be supplied useful information for investigating biological roles of miRNAs in ruminants.Keywords: Pre-miRNA Genes, Ruminants, Sheep, Goat, Support Vector Machine
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Pages 171-176At the present study in order to detect major genes in a commercial broiler line Bayesian method as the most powerful statistical method in detection of major genes was used. After preliminary data editing, data of body weight (BW) at birth and six weeks of age of 14 and 35 generations respectively were analyzed using iBay software. The results verified segregation of major gene for two economical traits investigated at the current study. Compared to the effect of major genes, the polygenic effect on BW at birth which is highly biased by maternal genetic factors was proved to be stronger. However, our results confirmed that the role of major genes in determining BW at six weeks of age was more impactful than that of polygenic part, which highlights the importance of direct genetic effect on the trait. In this study, results of Bayesian segregation analysis confirm the segregation of major genes for the two traits, BW at birth and six weeks of age, which potentially paves the way for future studies to detect major genes.Keywords: Bayesian segregation analysis, Commercial broiler line, Major gene
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Pages 177-184In this study a bio-economic model was used for a flock with 195 breeding ewes and 20 rams to determine economic values of important traits in Zel sheep of Golestan including litter size, pre-weaning survival, post-weaning survival, ewe survival, birth weight, weaning weight, yearling weight, ewe mature weight, dressing percentage, conception rate and wool weight. In this model, fixed environment was assumed and herd profit was estimated from difference between costs and revenues. Relative economic values of the traits were estimated based on wool weight. The highest economic value was found for litter size with relative economic value of 139.82. After litter size, the most important relative economic values were 3.81 and 3.66 for ewe survival and dressing percentage, respectively. Economic values of all traits were positive except for birth weight (-0.98). Sensitivity analysis of economic values were carried out for 20% increase and decrease in price levels of input (concentrate, forage) and output (meat, wool) system. Economic values of all traits except for birth weight and wool weight were changed by changing the price of meat. The economic values of ewe mature weight, dressing percentage and wool weight did not change with change in price of concentrate and forage .Sheep farming system can increase in profits by increasing in the amount and value of product. As the highest economic values were found for amount and value of the products especially amount of products, in order to increase system profit it is better to select for these traits in a breeding program.Keywords: Bio-economic model, Economic values, Sheep
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Pages 185-194The aim of this study was to estimate inbreeding coefficient and its impact on wool performance in Lori-Bakhtiari sheep. In this research, wool weight records of 6234 lambs born from 273 rams and 1924 ewes were used. The data were collected at Shahrekord Sholi station during 1990-2010. In total pedigree, 1764 animals were inbred. Averages of inbreeding coefficient for total and inbred population were estimated at 1.02 and 2.32 respectively. The inbreeding effects reduced wool weight performance approximately 4.2±1 g for each percentage of increase in inbreeding. Increasing 1% of inbreeding coefficient of male and female lambs was respectively accompanied with decreasing 5±1 and 3±1 g in wool weight. This decreasing was 4.6±1 and 2±1 g for single and twine lambs respectively. Annual trend in inbreeding coefficient for total and inbred population were 0.098±0.01 and -0.72±0.1 kg respectively that was statistically significant (PKeywords: Inbreeding, Lori-Bakhtiari Sheep, Regression, Wool Weight
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Pages 195-200Economically 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.Keywords: (Co)Variance Components, Egg, Native Fowls, Quality
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Pages 201-209The objectives of present study were to estimate the genetic and permanent environmental covariance components and genetic and phenotypic trends of test-day records of somatic cell score (SCS) of the first lactation Iranian Holstein cows. Dataset included the 108995 test day records were collected by the Animal Breeding Center of Iran from 2001 to 2010. The GLM procedure of SAS software was used for fitting the fixed effects in the statistical models of analysis. All analyses were performed using the AIREML algorithm of WOMBAT software. 16 different random regression models were studied and compared based on Akaikes information criterion. Random regression model with Legendre polynomial functions of orders of 4, 4, 5 were chosen to fit fixed regression, additive genetic and permanent environmental effects, respectively, and residual variance was assumed in 4 heterogeneous levels during the lactation. Estimation of heritability was low (0.022 to 0.032) that indicated this trait mostly affected by environmental factors. Genetic and environmental correlations between daily SCS were high for adjacent tests and low between the beginning and the end of lactation. The estimated environmental correlations were lower than the genetic correlations in all stages of lactation. Annual genetic and phenotypic trends were -0.59±0.103 and -0.08±0.002, respectively, for SCS trait. Both genetic and phenotypic trends for SCS were significant (PKeywords: Dairy Cow, Genetic Parameters, Genetic Progress, Mastitis, Random Regression Model