Effect of ruminal mechanical stimulating brushes on the performance of lactating Holstein dairy cows

Cilj istraživanja bio je potvrditi hipotezu da umjetne četke za stimulaciju buraga (RMS četke) mogu djelomično zamijeniti funkciju strukturnih vlakana te povećati proizvodnju ili kvalitetu mlijeka. Kako bi se umanjili rizici hranidbe niskom razinom fizikalno učinkovitih neutralnih deterdžent vlakana (peNDF) na goveda, ispitivana je primjena četki za stimulaciju buraga kod 22 visoko proizvodne holstein mliječne krave. Krave su podijeljene u eksperimentalnu skupinu u kojoj su primijenjene RMS četke i kontrolnu skupinu bez primjene. Krave su hranjene sa četiri eksperimentalna potpuno izmiješana obroka s nepromjenjivim količinama silaže lucerne, kukuruzne silaže, silaže cijelog klipa kukuruza te različitih količina pivskog tropa i pšenične slame. Sadržaj peNDF u obrocima je bio redom 10,9, 13,0, 12,6 i 14,0 %. Istraživanje je trajalo 18 tjedana, a sve su krave hranjene obrokom s niskim sadržajem strukturnih vlakana povezanim s rizikom pojave subakutne ruminalne acidoze (SARA). U eksperimentalnoj skupini, tri RMS četke oralno su umetnute u burag posebnim aplikatorom. Tijekom istraživanja, promatran je utjecaj primjene RMS četki na konzumaciju, buražnu fermentaciju i proizvodnju mlijeka. Uzorak buražnog soka uzorkovan je želučanom sondom te je u njemu određen pH i sadržaj hlapljivih masnih kiselina te amoni¬jskog dušika. Primjena RMS četki značajno je povećala konzumaciju i proizvodnju mlijeka samo kada je eksperimentalna skupina hranjena obrokom s 13,0 % peNDF, te nije utvrđena jasna povezanost između sadržaja peNDF obroka i primjene RMS četki. Kvaliteta mlijeka, pH buraga i sadržaj produkata fermentacije nisu značajno povećani primjenom RMS četki. Iako je tehnologija RMS četki samo djelomično smanjila potrebe za peNDF, ona može smanjiti rizik pojave SARA.The aim of this study was to confirm the hypothesis that artificial brushes administered to the rumen can partially replace the function of structural fibre, and increase milk production or quality. To mitigate the risks of feeding low levels of physically effective neutral detergent fibre (peNDF) to cattle, the administration of ruminal mechanical stimulating (RMS) brushes was examined in 22 high-yielding lactating Holstein dairy cows. The cows were divided into an experimental group equipped with RMS brushes and a control group without RMS. Cows were fed four experimental total mixed rations (TMR) consisting of fixed amounts of alfalfa silage, maize silage, rush corn cob mix silage and different proportions of brewer\u27s grains, concentrate and wheat straw. The TMRs had the following 4 peNDF contents: 10.9%. 13.0%, 12.6% and 14.0%. The duration of the experiment was 18 weeks. All cows were fed TMRs with a low structural fibre content near levels associated with a risk of subacute ruminal acidosis (SARA). For the RMS brush group, 3 RMS brushes were inserted orally into the rumen using a special applicator. The effects of RMS brushes on feed intake, rumen fermentation and milk production were evaluated. Ruminal fluid (250 mL) was taken using a stomach tube for pH, volatile fatty acids and ammonia nitrogen analysis. A significant increase was found for the feed intake and milk yield of the RMS group fed the TMRs with 13.0% peNDF although no relationship between peNDF content and RMS TMRs was found. No significant increase in milk quality, rumen pH or rumen fermentation metabolites was declared for the group with RMS brushes. Although RMS brush technology only partially reduced the requirements for peNDF, it may decrease the risk of SARA

Shape-controlled continuous synthesis of metal nanostructures

A segmented flow-based microreactor is used for the continuous production of faceted nanocrystals. Flow segmentation is proposed as a versatile tool to manipulate the reduction kinetics and control the growth of faceted nanostructures; tuning the size and shape. Switching the gas from oxygen to carbon monoxide permits the adjustment in nanostructure growth from 1D (nanorods) to 2D (nanosheets). CO is a key factor in the formation of Pd nanosheets and Pt nanocubes; operating as a second phase, a reductant, and a capping agent. This combination confines the growth to specific structures. In addition, the segmented flow microfluidic reactor inherently has the ability to operate in a reproducible manner at elevated temperatures and pressures whilst confining potentially toxic reactants, such as CO, in nanoliter slugs. This continuous system successfully synthesised Pd nanorods with an aspect ratio of 6; thin palladium nanosheets with a thickness of 1.5 nm; and Pt nanocubes with a 5.6 nm edge length, all in a synthesis time as low as 150 s

An assessment of hydrocarbon species in the methanol-to-hydrocarbon reaction over a ZSM-5 catalyst.

A ZSM-5 catalyst is examined in relation to the methanol-to-hydrocarbon (MTH) reaction as a function of reaction temperature and time-on-stream. The reaction profile is characterised using in-line mass spectrometry. Furthermore, the material contained within a catch-pot downstream from the reactor is analysed using gas chromatography-mass spectrometry. For a fixed methanol feed, reaction conditions are selected to define various stages of the reaction coordinate: (i) initial methanol adsorption at a sub-optimum reaction temperature (1 h at 200 °C); (ii) initial stages of reaction at an optimised reaction temperature (1 h at 350 °C); (iii) steady-state operation at an optimised reaction temperature (3 days at 350 °C); and (iv) accelerated ageing (3 days at 400 °C). Post-reaction, the catalyst samples are analysed ex situ by a combination of temperature-programmed oxidation (TPO) and spectroscopically by electron paramagnetic resonance (EPR), diffuse-reflectance infrared and inelastic neutron scattering (INS) spectroscopies. The TPO measurements provide an indication of the degree of 'coking' experienced by each sample. The EPR measurements detect aromatic radical cations. The IR and INS measurements reveal the presence of retained hydrocarbonaceous species, the nature of which are discussed in terms of the well-developed 'hydrocarbon pool' mechanism. This combination of experimental evidence, uniquely applied to this reaction system, establishes the importance of retained hydrocarbonaceous species in effecting the product distribution of this economically relevant reaction system