This study is the first to evaluate the effects of five seaweeds (Ulva sp., Laminaria ochroleuca, Saccharina latissima, Gigartina sp., and Gracilaria vermiculophylla) on gas and methane production ...and ruminal fermentation parameters when incubated in vitro with two substrates (meadow hay and corn silage) for 24 h. Seaweeds led to lower gas production, with Gigartina sp. presenting the lowest value. When incubated with meadow hay, Ulva sp., Gigartina sp. and G. vermiculophylla decreased methane production, but with corn silage, methane production was only decreased by G. vermiculophylla. With meadow hay, L. ochroleuca and S. latissima promoted similar methane production as the control, but with corn silage, L. ochroleuca increased it. With the exception of S. latissima, all seaweeds promoted similar levels of total volatile fatty acid production. The highest proportion of acetic acid was produced with Ulva sp., G. vermiculophylla, and S. latissima; the highest proportion of butyric acid with the control and L. ochroleuca; and the highest proportion of iso-valeric acid with Gigartina sp. These results reveal the potential of seaweeds to mitigate ruminal methane production and the importance of the basal diet. To efficiently use seaweeds as feed ingredients with nutritional and environmental benefits, more research is required to determine the mechanisms underlying seaweed and substrate interactions.
Abstract
Supplementing diets with rumen-protected lysine is a common strategy to meet the nutritional needs of high-producing dairy cows. This work addressed two separate but crucial issues: the ...lysine protection degree across the entire digestive tract as well as the production scalability of the proposed delivery systems. This was achieved by evaluating, in vitro or ex vivo, previously developed rumen-resistant lipid nanoparticles regarding their stability in the digestive tract and in the bloodstream of the dairy cow as well as how their production could be scaled-up. Results showed that the developed nanoparticles were able to resist digestion along the digestive tract but were degraded in the blood over 24 h. Thus, releasing their content to be used by the animal. In vitro viability assays were also performed, with the nanoparticles being found not to be inherently toxic when using nanoparticle concentrations up to 1 mg/mL. Results showed that neither the purity of the used lipids nor the production method significantly altered the nanoparticles’ properties or their ruminal resistance. Furthermore, the shelf-life of these nanoparticles was assessed, and they were found to retain their properties and remain usable after at least 1 month of storage. Moreover, a pilot-scale production allowed the production of nanoparticles with similar properties to the previous ones made using standard methods. To summarize, the proposed rumen-resistant nanoparticles presented potential as orally ingested lysine delivery systems for dairy cattle supplementation, being capable of a large-scale production using cheaper components while maintaining their properties and without any efficiency loss. It should however be noted that these results were obtained mainly in vitro and further in vivo bioavailability and production experiments are needed before this technology can be confirmed as a viable way of delivering lysine to dairy cows.
Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant ...products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18:1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18:2n-6 and 18:3n-3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18:0 might be produced during biohydrogenation of the 18:3n-3.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study characterized the mineral composition of 15 common Portuguese seaweed (green, brown, and red) species. Total measured mineral content ranged from 10.9 g kg
−1
dry matter (DM) in
Gracilaria ...vermiculophylla
to 71.0 g kg
−1
DM in
Codium adhaerens
, calcium being the mineral generally found in higher amounts. Overall, the results suggest that seaweeds have great potential as mineral sources for animal feeding, but a great variability between species was observed regarding their mineral profile. Compared to common animal feed ingredients, the studied seaweeds can be considered as good sources of calcium, magnesium, iron, iodine, copper, manganese, and selenium but are poor sources of phosphorous and zinc. The maximum level of dietary inclusion will be strongly dependent on the mineral profile of the seaweeds. Depending on the seaweed, the upper level of inclusion in poultry and swine diets may reach more than 40 %. The high iodine content of studied seaweeds limits their use in diets for horses, and, to a lesser extent, for ruminants. This work constitutes a paramount contribution regarding the use of seaweeds as mineral sources in animal diets, allowing a more precise choice of the algae species and level of inclusion to be used, thus assuring animal health and strengthening the seaweed industry through this underexploited application field.
Machine learning techniques are now well established in experimental particle physics, allowing detector data to be analyzed in new and unique ways. The identification of signals in particle ...observatories is an essential data processing task that can potentially be improved using such methods. This paper aims at exploring the benefits that a dedicated machine learning approach might provide to the classification of signals in dual-phase noble gas time projection chambers. A full methodology is presented, from exploratory data analysis using Gaussian mixture models and feature importance ranking to the construction of dedicated predictive models based on standard implementations of neural networks and random forests, validated using unlabeled simulated data from the LZ experiment as a proxy to real data. The global classification accuracy of the predictive models developed in this work is estimated to be >99.0%, which is an improvement over conventional algorithms tested with similar data. The results from the clustering analysis were also used to identify anomalies in the data caused by miscalculated signal properties, showing that this methodology can also be used for data monitoring.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Detailed mineral profile of a selection of commercially available complete dry dog foods was determined using ICP-MS (Se, Cu, Mn, Zn, and nonessential trace elements), flame photometry (Na and K) and ...atomic and molecular spectrophotometry (Ca, P, Mg, and Fe). The contribution of ingredients to the mineral composition was correlated to the food market segment. Results showed an oversupply of essential elements due to the energy density effect on feed intake. Additives contributed from 40.8 to 55.1% to the total trace elements contents. With the exception of Se, all trace elements were supplied above the nutritional requirements of adult dogs. Legal limits of Cu, Se, and Zn were surpassed. The content of nonessential trace elements included values in the range of nanograms to micrograms per kg, without surpassing safe upper limits. This work brings awareness to the need to find supplementation strategies that ensure nutritional adequacy and avoid waste.
Research on gastric lipolysis of commercial cow’s milk with different fatty acid (FA) compositions is scarce. Gastric lipase exhibits specificity for the sn-3 chain position of triacylglycerols, ...whose structure is influenced by milk FA composition. Therefore, during gastric digestion of conventional (C) vs pasture-based (P) milk, differences may occur on lipolysis, which has impact on free FA available, influencing their absorption/metabolism rate and physiological hormonal responses. Those two milk types were subjected to the INFOGEST semi-dynamic digestion model. Five gastric emptying points were analyzed for oxidative degradation of polyunsaturated fatty acids (PUFA) and individual free FA. The relative release of medium-chain FA (C8:0–C12:0) was higher than that of longer-chain FA (C14:0–C18:0), and a linear increase in markers of PUFA oxidative degradation occurred along gastric digestion. Quantitatively, C8:0, C18:2n-6, C18:3n-3, and CLAc9t11 were higher (P < 0.001) in P milk when compared with C milk.
Yeast-derived products containing β-glucans have long been used as feed supplements in domesticated animals in an attempt to increase immunity. β-glucans are mainly recognized by the cell surface ...receptor CLEC7A, also designated Dectin-1. Although the immune mechanisms elicited through Dectin-1 activation have been studied in detail in mice and humans, they are poorly understood in other species. Here, we evaluated the response of bovine monocytes to soluble and particulate purified β-glucans, and also to Zymosan. Our results show that particulate, but not soluble β-glucans, can upregulate the surface expression of costimulatory molecules CD80 and CD86 on bovine monocytes. In addition, stimulated cells increased production of IL-8 and of
TNF, IL1B
, and
IL6
mRNA expression, in a dose-dependent manner, which correlated positively with
CLEC7A
gene expression. Production of IL-8 and
TNF
expression decreased significantly after
CLEC7A
knockdown using two different pairs of siRNAs. Overall, we demonstrated here that bovine monocytes respond to particulate β-glucans, through Dectin-1, by increasing the expression of pro-inflammatory cytokines. Our data support further studies in cattle on the induction of trained immunity using dietary β-glucans.
Supplemental zinc from organic sources has been suggested to be more bioavailable than inorganic ones for dog foods. However, the bioavailability of zinc might be affected by dietary constituents ...such as phytates. The present study aimed to evaluate the effects of two zinc sources (zinc sulfate and zinc proteinate) and the addition of a multi-enzymatic complex from the solid-state fermentation of
Aspergillus niger
on end-products of fecal fermentation and fecal microbiota of adult Beagles fed a high-phytate diet. The experimental design consisted of three 4 × 4 Latin Squares with a 2 × 2 factorial arrangement of treatments (
n
= 12 Beagles), with four periods and four diets: zinc sulfate without (IZ) or with (IZ +) enzyme addition, and zinc proteinate without (OZ) or with (OZ +) enzyme addition. Enzyme addition significantly affected Faith’s phylogenetic diversity index, whereas zinc source did not affect either beta or alpha diversity measures. Linear discriminant analysis effect size detected nine taxa as markers for organic zinc, 18 for inorganic source, and none for enzyme addition. However, with the use of a negative binomial generalized linear model, further effects were observed. Organic zinc was associated with a significantly higher abundance of Firmicutes and lower Proteobacteria and Bacteroidetes, although at a genus level, the response varied. The DNA abundance of
Clostridium
cluster I,
Clostridium
cluster XIV,
Campylobacter
spp., Ruminococcaceae,
Turicibacter
, and
Blautia
was significantly higher in dogs fed IZ and IZ + diets. Higher abundance of genus
Lactobacillus
was observed in dogs fed enzyme-supplemented diets. End-products of fecal fermentation were not affected by zinc source or enzymes. An increase in some taxa of the phyla Actinobacteria and Firmicutes was observed in feces of dogs fed organic zinc with enzyme addition but not with inorganic zinc. This study fills a gap in knowledge regarding the effect of zinc source and enzyme addition on the fecal microbiota of dogs. An association of zinc bioavailability and bacteria abundance is suggested, but the implications for the host (dog) are not clear. Further studies are required to unveil the effects of the interaction between zinc sources and enzyme addition on the fecal microbial community.
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