جستجوی مقالات مرتبط با کلیدواژه "نانو ذرات نقره" در نشریات گروه "علوم دام"

 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.

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.

 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.

 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.

Nowadays silver nanoparticles are being considered as an alternative to antibiotics. Silver is one of the most important elements in nanotechnology due to extensive antibacterial activity. The aim of present experiment was to evaluate the effect of silver nanoparticles coated on zeolite and organic acids on performance, intestinal morphology, gastrointestinal microbial population and carcass characteristics in broiler chickens under heat stress conditions. A total of 375 day-old (Cobb 500) broiler chickens were randomly assigned to 5 treatment groups consisting of 5 replicates of 15 birds in each. Treatments included: (1) basal diet, (2) basal diet containing 1% zeolite, (3) basal diet containing 1% of zeolite-coated with 0.5% silver nanoparticles, (4) Basal diet containing 1 g/kg a mixture of organic acids and (5) Basal diet containing 1% of zeolite-coated with 0.5% of silver nanoparticles and 1g/kg a mixture of organic acids. Two chickens per each replicate were slaughtered on days 21 and 42 for measuring of the internal organs weight and microbial population enumerating, and on days 35 and 42 for morphology of the intestine. The experimental results showed that silver nanoparticles had higher feed conversion rate compared with other treatments. Also, villi length was significantly different between treatments and control group on d 35 of experiment (P<0.05). The silver nanoparticles treatment and the silver nanoparticles with organic acids treatment had the highest villi length on 42 d of experiment (P<0.05). The effect of experimental treatments had no significant effect on gastrointestinal microbial population on d 21 and 42 of experiment (P>0.05). In conclusion, the results of present study showed that silver nanoparticles coated on zeolite with organic acid could be used as a feed additive with no adverse effect under heat stress condition in broilers chicken treatments.

One of the new methods for drinking water disinfection in poultry farms is the use of silver nanoparticles (AgNPs). Anti-bacterial effect of silver had been known for disincentive activity of AgNPs. An early low fertility syndrome has been reported in broiler breeding farms. The aim of this study was to evaluate the effects of AgNPs on reproductive performance of male quails as a laboratory model. Twenty-four male quailswere used in four treatments with six replications. The treatments consisted of 0, 12, 36 and 108 ppm of silver nanoparticles, which were consumed in drinking water. Then blood samples and testes were collected after 42 days and body weight, daily sperm production, paired testes weight (g), gonado-somatic index (GSI), testosterone serum concentration and testicular histopathology indices were evaluated. There was significant decrease in the testes absolute weight in two groups of 36 and 108 ppm AgNPs (6.3-6.5 g) compared with control group (8.8 g, P<0.05). The GSI was also significantly (P<0.05) declined in 36 ppm AgNPs group (2.92±0.46%) as compared with control group (3.74±0.47%). The 108 ppm AgNPs group caused a dramatically reduction of daily sperm production (110.6±28.1×106) as compared to control (327.7±94.4×106, P<0.05). One of the most important histopathological findings was a depletion of cells in the seminiferous tubules of testis and spermatogenesis chain and a low density of spermatozoa in the proximal and distal efferent ductules in the 108 ppm AgNPs concentration. The results indicated that silver nanoparticles reduced the male reproductive performance in male quail.

This experiment was conducted to evaluate the effect of supplementing the diet with zeolite coated with silvernanoparticles on performance, intestinal morphology characteristics and ilium microbial population of broiler chickens in a completely randomized design with 375 day-old broiler chicks with five replicates per treatment and 15 chicks per replicate.Treatments were: 1) basal diet, 2) basal diet supplemented with1% zeoliteand 3, 4, and 5) basal diet supplemented with1% zeolitecoated and 0.25%, 0.5% and 0.75% nanosilver. Results showed that dietary supplementation with 1% zeolite and all level of silver nanoparticles had better feed conversion ratio than the basal diet on d 22-42 (P

This experiment was conducted to evaluate the Response of duodenum histomorphometric characteristics, pH and microbial population of alimentary canal to silver nanoparticles coated on zeolite with 375 Cobb 500 broiler chickens in a completely randomized design with 5 treatments and 5 replicates and 15 birds to each replicate. The examination treatments were: 1) control diet (C) 2) control diet supplemented with 1% zeolite (Z) (3, 4, and 5) control diet supplemented with 1% zeolite coated with 0.25% (NS25), 0.5% (NS50) and 0.75% (NS75) nanosilver. group NS50 increased villi surface area compared with the control treatment and group NS25 (P<0.05). On d 42, groups NS25 and NS50 increased crop lactobacillus population compared with control treatment and group Z (P<0.05). The use of all treatments (Z, NS25, NS50 and NS75) decreased ceca coliforms compared with the control treatment (P<0.05). Also, the all of treatments decreased crop pH compared with the control treatment (P<0.05). Groups NS50 and NS75 decreased ceca pH compared with the control treatment (P<0.05). In conclusion, the results of this study showed that silver nanoparticles coated on zeolite decreased pH and coliforms Harmful bacteria population and increased lactobacillus Beneficial bacteria and the end increased villi surface area of broiler chickens and it can be considered as a growth and health promoters.

Apoptosis is a form of cell death that is often regular and targeted in some cells¡ but it can be induced whit some drugs and toxins or pathogens also.This research was carried out on 240 one day-old male broiler chickens (Ross 308) in a completely randomized design (CRD) in four treatments at 0(control)¡ 4 ¡ 8 and 12 ppm levels of silver nanoparticles that was added to water intake with four repetitions within 16 separate cages and 15 birds in each pen. At the end of research (day 42)16 chicks were randomly selected and slaughtered and their kidney were examined with light microscope. TUNEL stainingshowed significant (p