فهرس المقالات production parameters

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  1 - اثرات دوز زیرکشندگی حشره کش پایریدالیل روی پارامتر های زیستی زنبور پارازیتویید Habrobracon hebetor Say (Hym., Braconidae)
  زهرا عابدی موسی صابر غلامحسین قره خانی علی مهرور
  در این مطالعه، آزمایشات زیست سنجی روی حشرات کامل زنبور به روش تماس با باقی مانده سم صورت گرفت. مقدار LC50 پایریدالیل روی حشرات کامل زنبور 2451 پی پی ام محاسبه شد. اثرات زیرکشندگی حشره کش پایریدالیل روی پارامترهای جدول زندگی، تولیدمثلی و بقای زنبور پارازیتویید بررس أکثر

  در این مطالعه، آزمایشات زیست سنجی روی حشرات کامل زنبور به روش تماس با باقی مانده سم صورت گرفت. مقدار LC50 پایریدالیل روی حشرات کامل زنبور 2451 پی پی ام محاسبه شد. اثرات زیرکشندگی حشره کش پایریدالیل روی پارامترهای جدول زندگی، تولیدمثلی و بقای زنبور پارازیتویید بررسی شد. با افزایش سن زنبور نرخ بقاء روند نزولی داشت. امید زندگی و نرخ مرگ و میر در تیمار پایریدالیل اختلاف چندانی با شاهد نداشت ولی در پارامترهای تولیدمثل زنبور بین شاهد و پایریدالیل اختلاف معنی دار بود. درصد تلفات در مرحله تخم و لارو توسط تیمار حشره کش تحت تاثیر قرار گرفت، ولی درصد ظهور حشرات کامل بین شاهد و تیمار حشره کش اختلاف معنی داری نداشت. این نتایج نشان داد که پایریدالیل اثر کشندگی چندانی روی زنبور ندارد، هم چنین کم ترین تاثیر سوء روی پارامترهای جدول زندگی زنبور داشت. در صورت تایید نتایج در مطالعات تکمیلی مزرعه ای، از این حشره کش می توان همراه با این عامل کنترل بیولوژیک در برنامه های مدیریت تلفیقی آفات استفاده نمود. تفاصيل المقالة
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  2 - Determination of <i>in vitro</i> Gas Production Kinetics by Adding <i>Leucaena leucecophala</i> and Corn Oil to the Ration in Different Ratios
  C.T. Noviandi K. Kustaantinah A. Irawan B.P. Widyobroto A. Astuti
  This study was aimed to determine in vitro gas production kinetics and organic matter digestibility (IVOMD) of ration added by Leucaena leucecophala and corn oil (CO) at various ratios. Four levels of Leucaena leucecophala (0%, 25%, 50%, and 75%, DM basis) and three lev أکثر

  This study was aimed to determine in vitro gas production kinetics and organic matter digestibility (IVOMD) of ration added by Leucaena leucecophala and corn oil (CO) at various ratios. Four levels of Leucaena leucecophala (0%, 25%, 50%, and 75%, DM basis) and three levels of corn oil (0%, 1%, and 2% of substrate) were arranged in a 4 &times; 3 factorial design. Hohenheim in vitro gas production procedure was employed to determine gas production kinetics, IVOMD, and partitioning factor (PF) value of the experiment. Supplementation of leucaena at 25% (L25) increased IVOMD (%), potential degradation fraction, cumulative gas production (GP) (mL), and metabolizable energy (ME) value (MJ/kg DM) of the ration (p &lt;0.01). There was no effect on in vitro gas production kinetics when leucaena was given at higher levels in comparison with L25 (P&gt;0.05). Besides, corn oil supplementation to the substrate did not negatively affect IVOMD and gas production kinetics. Instead, 2% of corn oil supplementation increased GP (p &lt;0.05). Indicator for microbial efficiency as measured with PF value increased with leucaena and CO supplementation (p &lt;0.05). The results indicated that incorporation of 25% leucaena and 2% of corn oil in the ration improved in vitro organic matter digestibility and gas production kinetics while a higher rate of supplementation did not give significant contribution in term of gas production on in vitro rumen fermentation system. Further study in chemical and biological treatment of leucaena or tannins sources and corn oil is needed to investigate specific mechanisms in modulating rumen fermentation in vitro and in vivo. تفاصيل المقالة
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  3 - Effects of Photoperiods during the Laying Period on Broiler Breeder Performance
  ت. مکرمی ن. هدایت ایوریق ب. نویدشاد
  The effects of increasing the laying period day-length from 13 to 16 hours were examined in Ross (308) broiler breeders. The birds reared on 8-h photoperiods and then were photo-stimulated at 21 weeks by increasing the photoperiods from 8 h of light, 16 h of darkness (8 أکثر

  The effects of increasing the laying period day-length from 13 to 16 hours were examined in Ross (308) broiler breeders. The birds reared on 8-h photoperiods and then were photo-stimulated at 21 weeks by increasing the photoperiods from 8 h of light, 16 h of darkness (8L:16D) to 11L:13D. Then the birds were given an additional 60 min of light per week cumulatively, such that in different experimental groups the 12L:12D, 13L:11D, 14L:10D, 15L:9D and 16L:8D photoperiods were achieved in 22, 23, 24, 25 and 26 weeks of age, respectively. The photoperiods remained unchanged until the experiment was finished at 50 weeks of age. The 16L:8D group had a poorer feed conversion and less egg production and egg mass than the other 3 groups (P&lt;0.05). The total settable egg percentage was significantly lower for 15L:9D and 16L:8D than for 13L:11D and 14L:10D birds (P&lt;0.05). The 13L:11D and 14L:10D h hens had more double-yolked and broken or abnormal eggs, followed by the 15L:9D h birds, and the 16L h birds (P&lt;0.05). The mean egg weight of 14L:10D birds was significantly more than for 16-L h birds (P&lt;0.05), with 13L:11D and 14L:10D birds were intermediated (P&lt;0.05). The percentage of hatchability was higher in 13L:11D h hens followed by the 15L:9D and the 16L:8D birds (P&lt;0.05), with 14L:10D h hens intermediated between 13L:11D and 15L:9D groups. The findings of this study suggest that 13L:11D was the optimal photoperiods for Ross 308 broiler breeders in the laying period up to 50 weeks of age. تفاصيل المقالة
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  4 - Evaluation of the Probiotic Potential of some Native <i>Lactobacillus</i> Strains on the Laying Performance and Egg Quality Parameters of Japanese Quails
  س.ع. سیادتی ی. ابراهیم نژاد غ. صالحی جوزانی ج. شایق
  The objective of the present study was to evaluate the probiotic effects of different concentrations of four selected native Lactobacillus strains on laying performance and egg quality parameters of quails. To do this, a six-week farm trial was performed in completely r أکثر

  The objective of the present study was to evaluate the probiotic effects of different concentrations of four selected native Lactobacillus strains on laying performance and egg quality parameters of quails. To do this, a six-week farm trial was performed in completely randomized design with seven different probiotic treatments of four replicates each consisting of eight quails, resulting in a total of 224 quails. Four native Lactobacillus strains whose probiotic potentials had previously been confirmed at in vitro levels were cultured in a 10 liter batch fermentor and lyophilized (1010 CFU/g). Treatments were as follows: T1: control (basal diet without probiotics); T2: basal diet + Primalac&reg; (454 g/ton); T3: basal diet + Protexin&reg; (50 g/ton); and T4, T5, T6, and T7: four native strains in levels of 50, 100, 150, and 200 g/ton diets, respectively. The native strains and Protexin&reg; could significantly improve egg production, feed conversion ratio (FCR), and egg mass during the laying period (P&lt;0.05), whereas no significant effect was observed on feed intake and egg weight. The probiotic treatments had significant positive effects on the albumen height, Haugh unit, and internal quality unit (IQU) (P&lt;0.05), whereas there was no difference between the treatments in terms of egg shell weight, egg yolk weight, and egg albumen weight of the quails (P&gt;0.05). It can be concluded that the use of native strains (a 50 g/ton diet) improved the performance (egg production, egg mass, and FCR) and egg quality parameters (Haugh unit and IQU) of quails. تفاصيل المقالة