پديد آورندگان :
ابراهيمي خرم آبادي، الياس مجتمع آموزش عالي تربت جام - گروه علوم دامي، تربت جام، ايران , كاظمي، محسن مجتمع آموزش عالي تربت جام - گروه علوم دامي، تربت جام، ايران , حيدري، سميه مجتمع آموزش عالي تربت جام - گروه شيمي، ايران
كليدواژه :
توليد گاز , خوراك , شكمبه , گوش‌بره , نانو ذرات نقره
چكيده فارسي :
اين آزمايش با هدف بررسي اثر مقادير مختلف نانو ذرات نقره سنتز شده به روش زيستي از عصاره گياه گوش‌بره سفيد بر تخمير شكمبه‌اي در شرايط برون‌تني انجام شد. جهت تهيه عصاره گياه گوش‌بره سفيد، يك ميلي‌ليتر از عصاره تهيه‌شده از اندام‌هاي هوايي گياه به محلول نيترات نقره 76/4 ميلي‌مولار در 84/6 pH= اضافه گرديد و به مدت 25 دقيقه در دماي 77 درجه سلسيوس مورد انكوباسيون قرار گرفت. اثرات افزايش نانو ذرات سنتز شده از گياه گوش‌بره سفيد (0، 125 و 250 ميكروگرم در ميلي‌ليتر) بر خصوصيات تخميري جيره گاوهاي پرتوليد با استفاده از روش توليد گاز در قالب طرح كاملاً تصادفي مورد ارزيابي قرار گرفت. افزايش مقدار نانو ذرات نقره در تيمارهاي آزمايشي تأثير معني‌داري بر ظرفيت توليد گاز از بخش قابل تخمير، نرخ توليد گاز و حجم گاز تجمعي توليدي (ميلي‌ليتر/ميلي‌گرم ماده خشك) در ساعات مختلف انكوباسيون نداشت. در اين آزمايش بين تيمارهاي مختلف از نظر قابليت‌هضم ظاهري ماده خشك، ماده آلي، مقدار ماده آلي هضم‌شده واقعي، انرژي قابل‌‌متابوليسم، اسيدهاي چرب فرار، شاخص بخش‌پذيري، توليد توده ميكروبي و بازده آن اختلاف معني‌داري وجود نداشت. در تيمار يك (فاقد نانو ذرات نقره سنتز شده به روش زيستي از عصاره گياه گوش‌بره سفيد) همبستگي منفي و معني‌دار بين هضم ماده خشك، قابليت‌هضم ماده آلي با حجم گاز تجمعي توليدي در ساعات 12 و 24 انكوباسيون و در تيمار دو (حاوي 125 ميكروگرم در ميلي‌ليتر نانو ذرات نقره سنتز شده به روش زيستي از عصاره گياه گوش‌بره سفيد) همبستگي منفي و معني‌دار بين قابليت‌هضم ماده آلي، شاخص بخش‌پذيري با حجم گاز تجمعي توليدي در ساعات مختلف انكوباسيون ثبت گرديد. مكمل كردن مقادير افزايشي نانو ذرات نقره توانست فراسنجه‌هاي توليد گاز در خوراك پايه را تغيير دهد.
چكيده لاتين :
Introduction[1] The anaerobic microbial fermentative digestion of feedstuffs in the rumen is not efficient. The gases are considered as waste products of rumen fermentation and also pollutants of the environment. Recent studies indicated that some metal nanoparticles (NPs) were toxic to rumen microbial population and inhibit methane production in anaerobic conditions. Plant extracts can be used to produce cost effective and eco-friendly green nanoparticles. Phlomis cancellata Bunge with Persian names Gushbarre sefid has high medicinal value and antibacterial properties and distributed dramatically in Khorasan, Mazandaran and Golestan. Hence, there is potential of using bio-synthesized nanoparticles in ruminant nutrition. However, there is not enough information regarding the effect of green nanoparticles on runminal condition. Therefore, the present investigation was carried out to study the effect of green silver nanoparticles synthesized via Phlomis cancellata Bunge extract on rumen fermentation in vitro.
Materials and methods Synthesis of sliver nanoparticles was prepared by adding of 1 ml of the aqueous extract to 4.76 mM sliver nitrate solution (pH= 6.84) allowed to react at 77 °C for 24.79 min in the dark to minimize the photo activation of silver nitrate. The color change of solution from yellow to brown after 3 min of incubation is indicative of the bioreduction of Ag+ ions in the solution to Ag°. Effects of increasing the concentration of green silver nanoparticles synthesized via Phlomis cancellata Bunge extract (0, 125 and 250 µg/ml) on rumen fermentation were evaluated using in vitro gas production technique. Gas production volumes were recorded at 3, 6, 9, 12, 24, 48, 72 and 96 h of incubation and then gas production kinetic was estimated. The obtained data from gas production at 24 h after incubation were used for estimation of digestible dry and organic matter, metabolisable energy, short chain fatty acids, partitioning factor, microbial biomass production and microbial biomass production efficiency.
Results and Discussion The increasing level of green silver nanoparticles synthesized via Phlomis cancellata Bunge extract did not significantly affect in vitro potential of gas production and gas production rate. For the cumulative gas production, no significant difference was found among the treatments. The lowest and highest in vitro potential of gas production, gas production rate and cumulative gas production was recorded for treatments 3 and 1, respectively. Silver nanoparticles exhibit unique bacteriostatic and bactericidal properties. At the atomic level, silver has the ability to absorb oxygen and acts as an oxidation catalyst. Atomic oxygen absorbed on the silver surface reacts with the thiol groups surrounding the surface of bacteria and viruses and removes hydrogen atoms. The bacterium loses respiration ability by disruption of the so-called respiratory channel, which results in bacterial death. The apparent in vitro dry matter digestibility and organic matter digestibility and true in vitro organic matter digestibility, were not significantly affected by addition of green silver nanoparticles synthesized via Phlomis cancellata Bunge extract. Addition of green silver nanoparticles synthesized via Phlomis cancellata Bunge extract failed to affect metabolisable energy, short chain fatty acids, partitioning factor, microbial biomass production and microbial biomass production efficiency. However, the lack of significant effect of the synthesized silver nanoparticles on the digestibility may be due to factors such as concentration, surface capacity, size, and other properties of silver nanoparticles. For treatment 1, the cumulative gas production over 24 and 48 h was negatively correlated apparent in vitro dry matter digestibility and organic matter digestibility. There was significant negative correlation between apparent in vitro organic matter digestibility and partitioning factor with cumulative gas production during hours of incubation for treatments 2. No significant correlation was found between apparent in vitro dry matter digestibility and organic matter digestibility and partitioning factor with the volume of cumulative gas produced during different incubation hours in for treatments 3.
Conclusion Supplementing of green silver nanoparticles synthesized via Phlomis cancellata Bunge extract could modify the characteristics of gas production and fermentation parameters basal diet and reduce the side effects of the anaerobic microbial fermentation. However, additional microbial studies with different level of green silver nanoparticles are necessary to determine the mode of action. Additionally, further in vivo work is needed to assess the effect of green silver nanoparticles inclusion on animal performance when cattle are fed ingredients commonly used in beef feedlot or dairy diets.
