Feed Sites Research Articles

Состав микрофлоры химуса пищеварительной системы и молочная продуктивность коров в период раздоя под влиянием комплексного биопрепарата

Abstract. Understanding the relationships between the microbiome of the digestive system, the use of probiotic supplements and zootechnical indicators in cows is the key to developing new strategies to increase milk yields. Purpose of research to study the composition of the microflora of the digestive system chyme and dairy productivity of cows under the influence of a complex biological preparation. Research methods. The experiment was carried out on of cows of black-and-white holsteinized. Groups were formed: control group I (who received the main ration (MR)) and experimental group II (who received MR and the “AntiKlos” feed additive). The bacterial community of the scar was evaluated by NGS-sequencing, the intestinal microflora, litter and feed were evaluated using real-time PCR. Results showed that the use of the “AntiKlos” feed additive on livestock allowed to increase the average daily milk yield to 7.5 kg compared with control I (P = 0.05). The bacteria Bacteroidetes were the most abundantly represented (P ≤ 0.05) in the rumen – from 20.9 ± 4.36 and up to 55.3 ± 6.74 %. It was shown for the first time that under the influence of the introduction of the “AntiKlos” feed additive into the diet, there was also a 16.1-fold decrease in Fusobacteria phylum bacteria in experimental group II compared with control I (P < 0.05). In addition, the use of the “AntiKlos” feed additive led to the complete disappearance of such species as Streptococcus caprae, S. didelphis, Mycoplasma conjunctivae in the rumen, among which opportunistic and pathogenic forms are often found, which is the scientific novelty of the study. Similar bacterial taxa were found in the food from the feed table, litter and rectum of almost all the dairy cows studied. In the rectal chyme of cows of the experimental group, the number of taxa such as Clostridium spp., Enterobacteriaceae and Staphylococcus spp. decreased in comparison with control I (P ≤ 0.05). Thus it is necessary to pay attention to increasing the efficiency of animal husbandry by regulating the microbiomes of cows, as well as the microflora of feed and housing sites.

Microplastics in water, feed and tissues of European seabass reared in a recirculation aquaculture system (RAS)

Plastic particles (PLs) are ubiquitous in aquatic ecosystems, and aquaculture production is susceptible to contamination from external or endogenous sources. This study investigated PL presence in water, fish feed and body sites of 55 European seabass produced in a recirculating aquaculture system (RAS). Fish morphometric parameters and health status biomarkers were determined. A total of 372 PLs were recovered from water (37.2 PL/L), 118 PLs from feed (3.9 PL/g), and 422 from seabass (0.7 PL/g fish; all body sites analysed). All 55 specimens had PLs in at least two of the four body sites analysed. Concentrations were higher in the gastrointestinal tract (GIT; 1.0 PL/g) and gills (0.8 PL/g) than in the liver (0.8 PL/g) and muscle (0.4 PL/g). PL concentration in GIT was significantly higher than in muscle. Black, blue, and transparent fibres made of man-made cellulose/rayon and polyethylene terephthalate were the most common PLs in water and seabass, while black fragments of phenoxy resin were the most common in feed. The levels of polymers linked to RAS components (polyethylene, polypropylene, and polyvinyl chloride) were low, suggesting a limited contribution to the overall PL levels found in water and/or fish. The mean PL size recovered from GIT (930 μm) and gills (1047 μm) was significantly larger than those found in the liver (647 μm) and dorsal muscle (425 μm). Considering all body sites, PLs bioconcentrated in seabass (BCFFish >1), but their bioaccumulation did not occur (BAFFish <1). No significant differences were observed in oxidative stress biomarkers between fish with low (<7) and high (≥7) PL numbers. These findings suggest that fish produced in RAS are mainly exposed to MPs through water and feed. Further monitoring under commercial conditions and risk assessment are warranted to identify potential threats to fish and human health and define mitigating measures.

Using DNA metabarcoding to explore spatial variation in diet across European Hawfinch populations

The investigation of diet in avian species is essential for understanding their ecology and local adaptations, as well as long-term conservation. This can be particularly challenging because of the wide distribution and high ecological plasticity of many bird species. Here, we focused on the Hawfinch (<em>Coccothraustes coccothraustes</em>), which has shown variation in population trends. Across Europe, central and eastern European populations are moderately declining while western European populations are moderately increasing. Ecological drivers behind these differing trends are still unknown; one possibility is differences in diet, yet little research has been conducted into Hawfinch diet in mainland Europe or elsewhere. Dietary richness and variation are under-studied in woodland bird species, due primarily to challenges in accurately identifying plant and invertebrate taxa consumed. This study presents the first molecular dietary analysis of Hawfinch populations across two European countries. Faecal samples were collected between January and July of 2019 from Hawfinch caught at six artificial feed sites: two in Denmark and four in Germany. We successfully extracted DNA from 80 samples by amplifying plant Internal Transcribed Spacer 2 (ITS2) and invertebrate Cytochrome Oxidase Subunit 1 (COI) barcodes. A total of 35 plant and 37 invertebrate taxa were found, with plant and insect orders Fagales and Lepidoptera, respectively, the most frequently detected. Hawfinch dietary composition differed significantly between European countries, suggesting Hawfinch can make use of available food resources that are likely to differ spatially. Our study shows how DNA metabarcoding can be used to provide novel ecological information associated with under-studied bird species, thus providing essential information for future management and conservation of Hawfinch and their habitats.

DEAR: Deep Reinforcement Learning for Online Advertising Impression in Recommender Systems

With the recent prevalence of Reinforcement Learning (RL), there have been tremendous interests in utilizing RL for online advertising in recommendation platforms (e.g., e-commerce and news feed sites). However, most RL-based advertising algorithms focus on optimizing ads' revenue while ignoring the possible negative influence of ads on user experience of recommended items (products, articles and videos). Developing an optimal advertising algorithm in recommendations faces immense challenges because interpolating ads improperly or too frequently may decrease user experience, while interpolating fewer ads will reduce the advertising revenue. Thus, in this paper, we propose a novel advertising strategy for the rec/ads trade-off. To be specific, we develop an RL-based framework that can continuously update its advertising strategies and maximize reward in the long run. Given a recommendation list, we design a novel Deep Q-network architecture that can determine three internally related tasks jointly, i.e., (i) whether to interpolate an ad or not in the recommendation list, and if yes, (ii) the optimal ad and (iii) the optimal location to interpolate. The experimental results based on real-world data demonstrate the effectiveness of the proposed framework.

Vector genetics, insecticide resistance and gene drives: An agent-based modeling approach to evaluate malaria transmission and elimination.

Vector control has been a key component in the fight against malaria for decades, and chemical insecticides are critical to the success of vector control programs worldwide. However, increasing resistance to insecticides threatens to undermine these efforts. Understanding the evolution and propagation of resistance is thus imperative to mitigating loss of intervention effectiveness. Additionally, accelerated research and development of new tools that can be deployed alongside existing vector control strategies is key to eradicating malaria in the near future. Methods such as gene drives that aim to genetically modify large mosquito populations in the wild to either render them refractory to malaria or impair their reproduction may prove invaluable tools. Mathematical models of gene flow in populations, which is the transfer of genetic information from one population to another through migration, can offer invaluable insight into the behavior and potential impact of gene drives as well as the spread of insecticide resistance in the wild. Here, we present the first multi-locus, agent-based model of vector genetics that accounts for mutations and a many-to-many mapping cardinality of genotypes to phenotypes to investigate gene flow, and the propagation of gene drives in Anopheline populations. This model is embedded within a large scale individual-based model of malaria transmission representative of a high burden, high transmission setting characteristic of the Sahel. Results are presented for the selection of insecticide-resistant vectors and the spread of resistance through repeated deployment of insecticide treated nets (ITNs), in addition to scenarios where gene drives act in concert with existing vector control tools such as ITNs. The roles of seasonality, spatial distribution of vector habitat and feed sites, and existing vector control in propagating alleles that confer phenotypic traits via gene drives that result in reduced transmission are explored. The ability to model a spectrum of vector species with different genotypes and phenotypes in the context of malaria transmission allows us to test deployment strategies for existing interventions that reduce the deleterious effects of resistance and allows exploration of the impact of new tools being proposed or developed.

Совершенствование технологии приготовления кормовой смеси при реконструкции кормовых площадок

Совершенствование технологии приготовления кормовой смеси при реконструкции кормовых площадок

Nest survival, causes of failure and productivity of British Hawfinches Coccothraustes coccothraustes

ABSTARCTCapsule: Nest success rate of Hawfinches Coccothraustes coccothraustes within our study areas averaged 36% across five seasons, a level unlikely to be driving population declines and considerably higher than was suggested by recent estimates from the long-term Nest Record Scheme.Aims: To investigate potential habitat correlates of nest success and identify nest predators from an intensive study on Hawfinches. To compare nest success and habitat of these nests with those found by Nest Record Scheme (NRS) recorders and test whether there is evidence of a decline in nest success over time from the NRS data.Methods: Females trapped at feed sites were fitted with radio-tags and tracked back to nest sites providing a sample of nests for subsequent monitoring. Habitat measures potentially influencing survival were collected at nest sites and modelled against nest outcome. Nest success was compared with that from the long-term Nest Record Scheme. Nest cameras were deployed to identify predators.Results: Nest success varied among years, but the mean value was not substantially lower than other Hawfinch studies or from other species with similar nesting strategies. Apparent recent declines in success suggested by Nest Record Scheme data were not evident in our study areas. Only avian species were recorded predating nests and a number of partial predations were recorded. No correlation was found between overall success for study nests and the habitat or temporal measurements collected.Conclusions: Within our study areas, average Hawfinch nest success and productivity appeared to be sufficient to maintain local population stability though our sample size was modest and further work would be beneficial. General nest recording may have inherent biases that lead to an over-estimation of nest failure compared to those found by more structured study. Drivers of recent UK Hawfinch declines may be operating outside of the nesting season and/or in landscapes outside primary woodland.

WITHDRAWN: Novel polysulfone membrane covalent bearing functionalized ionic liquids and its catalytic performance for biomass inulin hydrolysis

Abstract Polysulfone powders covalently linked with acidic ionic liquids (ILs) as catalyst (PSF-ILs) were synthesized. It was prepared into casting solution to fabricate membrane via non-solvent induced phase separation method. Chemical structure of the PSF-ILs was confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The microstructure of PSF-ILs membranes was characterized by the scanning electron microscopy, pore size, porosity and contact angle measurements. The effects of the covalently incorporated ILs on the water flux, bovine serum albumin rejection and especially catalytic performance were investigated systematically to elucidate the microstructure-performance relationships. The structure of the membrane was regulated subtly by varying solvent or polymer concentration. Compared with the finger-like membrane, the resultant sponge-like membrane exhibited better catalytic performance for inulin hydrolysis due to higher porosity and specific surface area. Moreover, the effects of membrane thickness, porosity, reaction temperature and flux on catalytic performance of membrane that was constructed as a reactor were investigated. Interestingly, the turnover number of PSF-ILs membrane, i.e. the number of products generated by each active site of catalyst in unit time, was higher than the homogeneous ILs and PEK-C-ILs powders. Furthermore, the extended trial of the membrane demonstrated its reusability with only a little loss of catalytic activity. This novel catalytic membrane was first designed and prepared, not only subtly avoided the recycling of homogeneous ILs catalyst, but also effectively strengthened the mass transfer of substrates between the bulk of the feed and active sites on the pore wall, consequentially, improved the catalytic activity of ILs.

Breeding chronology and social interactions affect ungulate foraging behavior at a concentrated food resource.

Prey species must balance predator avoidance behavior with other essential activities including foraging, breeding, and social interactions. Anti-predator behaviors such as vigilance can impede resource acquisition rates by altering foraging behavior. However, in addition to predation risk, foraging behavior may also be affected by socio-sexual factors including breeding chronology and social interactions. Therefore, we investigated how time-of-day, distance-to-forest, group size, social interactions (presence of different sex-age class), and breeding chronology (pre-breeding, breeding, post-breeding seasons) affected probability of feeding (hereafter: feeding) for different sex and age-classes (mature males, immature males, adult females, and juveniles) of white-tailed deer at feed sites. We developed a set of candidate models consisting of social, habitat, reproductive, and abiotic factors and combinations of these factors. We then used generalized linear mixed models (GLMMs) to estimate the probability of feeding and used model averaging of competing models for multimodel inference. Each adult sex-age class’ feeding was influenced by breeding chronology. Juveniles were more likely to be feeding than adults in all seasons. Feeding increased with group size for all sex-age classes. The presence of a mature male negatively influenced the feeding of immature males and juveniles were more likely to be feeding when an adult female was present. Feeding decreased with increasing distance-to-forest for mature males but not for other sex-age classes. Our results indicate that each sex-age class modulates vigilance levels in response to socio-sexual factors according to the unique pressures placed upon them by their reproductive status and social rank.

Consumption of whole cottonseed by white-tailed deer and nontarget species

Supplementing diets of white-tailed deer (Odocoileus virginianus) with pelleted rations is an increasingly common practice aimed at increasing deer antler size on rangelands in Texas. Feed loss to consumption by various nontarget species (e.g., raccoons (Procyon lotor) and feral pigs (Sus scrofa)) raises both ecological and economic concerns. Whole cottonseed is a feedstuff that may afford a more targeted supplemental feeding effort. Accordingly, we determined: (1) consumption rates of whole cottonseed by feral pigs and raccoons in captivity; and (2) species visitation at feed sites and preference for whole cottonseed relative to whole corn under field conditions. For experiments 1 and 2, we trapped subadult feral pigs and raccoons (n = 16 for each) and randomly assigned them to 4 feed treatments. We weighed and took blood to assess gossypol levels from both pigs and raccoons every 2 weeks for 2 months. Pigs were adept at sorting cottonseed from their feed ration in the laboratory trial. Raccoons consumed cottonseed only under severe dietary stress (i.e., diets reduced to 60% of maintenance requirements). To supplement laboratory findings we used motion-triggered video camera systems to monitor species visitation and feeding behaviors in the field. Video surveillance (125 hours of recorded events) of feeders supported our observations from laboratory trials that cottonseed was unpalatable to feral pigs and raccoons, whereas white- tailed deer consumed cottonseed readily. Given our results, we believe that whole cottonseed merits further consideration as a supplement for free-ranging deer.

Biological consequences of winter‐feeding of mule deer in developed landscapes in Northern Utah

AbstractWinter‐feeding of mule deer (Odocoileus hemionus) in developed landscapes is often advocated by stakeholders to compensate for lost or fragmented winter range. However the reported benefits of winter‐feeding mule deer to increase survival and productivity in altered landscapes are mixed. Few studies have examined the long‐term effects of winter‐feeding on mule deer productivity. We studied the effects of a winter‐feeding program conducted in a developed landscape in northern Utah, USA from 2001 to 2006 on the productivity, survival, and mortality of 92 adult female deer (does) that were captured and radiocollared on 4 feed and 4 nonfeed sites. We also evaluated the potential for feeding programs to impact winter‐range habitat quality through increased browse utilization. Fawn production (P = 0.36), and survival (P = 0.12) did not differ for fed and nonfed does. Deer–vehicle collisions were the primary cause of mortality for radiocollared deer in both populations (P = 0.97). Utilization of desired browse species was higher on sites where deer were fed (P ≤ 0.001), although deer numbers were similar at feed and nonfeed sites. When developing big game winter‐feeding policies for developed landscapes, managers must consider the full range of long‐term potential population and habitat impacts to include increased anthropogenic‐related mortality and increased potential for habitat degradation prior to policy implementation. © 2011 The Wildlife Society.

The Effect of Snowmobile Trails on Coyote Movements Within Lynx Home Ranges

Abstract: Coyotes (Canis latrans) and Canada lynx (Lynx canadensis) are sympatric throughout much of the lynx's southern range. Researchers and managers have suggested that the presence of compacted snowmobile trails may allow coyotes to access lynx habitat from which they were previously excluded by deep, unconsolidated snow. This could then allow coyotes to more effectively compete with lynx for snowshoe hares (Lepus americanus), the lynx's primary prey. We investigated how coyotes interacted with compacted snowmobile trails by conducting carnivore track surveys and by snow tracking adult coyotes (4 M, 8 F) in areas of western Montana, USA, with both documented lynx presence and recreational snowmobile use. Coyotes remained in lynx habitat having deep snow throughout the winter months. They used compacted snowmobile trails for 7.69% of their travel distance and traveled on them for a median distance of 124 m. Coyotes used compacted forest roads (5.66% of total travel) and uncompacted forest roads (4.62% of total travel) similarly. Coyotes did not travel closer to compacted snowmobile trails than random expectation (coyote x̄ distance from compacted trails = 368 m, random expectation = 339 m) and the distance they traveled from these trails did not vary with daily, monthly, or yearly changes in snow supportiveness or depth. However, they strongly selected for naturally shallower and more supportive snow surfaces when traveling off compacted snowmobile trails. Coyotes were primarily scavengers in winter (snowshoe hare kills composed 3% of coyote feed sites) and did not forage closer to compacted snowmobile trails than random expectation. The overall influence of snowmobile trails on coyote movements and foraging success during winter appeared to be minimal on our study area. The results of this study will allow land managers to better assess the effects of snow‐compacting activities on coyotes and lynx.

Field evaluation of supplementary feed and water for the northern hairy-nosed wombat, Lasiorhinus krefftii

The northern hairy-nosed wombat, Lasiorhinus krefftii, is listed as critically endangered in Australia and is restricted to a single population of ~90 animals in central Queensland. The area receives low rainfall and is regularly subjected to periods of drought and therefore is at risk from wildfire. There is a clear link between good wet seasons and higher levels of reproductive activity. A long-term management goal of the L. krefftii recovery program has been to determine preferred feed of wombats and to gain acceptance of supplementary feed and water by L. krefftii in order to mitigate the effects of drought and wildfire and potentially increase fecundity and survivorship rates in the population. Prior to this study, there had been several unsuccessful attempts to induce L. krefftii to take supplementary feed and water, but the current study, which was of a longer duration, has shown that L. krefftii will readily take supplementary feed and water. In addition, L. krefftii prefers certain feed types (Complete-O (primarily steam-flaked barley with molasses and lucerne and oaten chaff), and Town and Country pellet mix (primarily wheat, barley and sorghum, with canola and soybean meal)) and will visit sources of feed and water on a nightly basis. Visits by L. krefftii to supplementary feed and water sites were related to the occurrence of rainfall, with visits declining after rain.

Theoretical and experimental study of methane steam reforming reactions over nickel catalyst

In this work we perform DFT theoretical calculations of methane and steam interactions on Ni(1 1 1) surface. The calculations allow us to improve our understanding of the competition between these reactants by catalytic sites in methane steam reforming (MSR) process. For this purpose we compare theoretical results with kinetic measurements of MSR on a Ni(II)–Al(III) catalyst prepared from lamellar double hydroxides as precursor. This comparison shows that, for low H 2O/CH 4 ratios methane and water intermediate species adsorb on different catalytic sites. While CHO species adsorbs on top of Ni atom, OH one occupies preferentially a tri-coordinate surface site. On the other hand, for high H 2O/CH 4 ratios a competency between these species by Ni sites would establish, diminishing methane conversion. In addition competition between methane and steam for Ni sites would lead to a decrease in CO production. Nevertheless, intermediate species adsorbed on different active sites would produce CO 2, whatever the steam/methane ratio. Thus, it would be optimum steam concentration in hydrocarbon feed and active sites distribution on catalyst surface, which could maximize H 2 production and minimize CO selectivity. The theoretical findings agree with kinetic measurements, which show that maximum methane conversion depends on steam partial pressure in the feed; whereas always, selectivity to CO 2 increases and to CO diminishes.

Evaluation of the influence of supplemental feeding of white-tailed deer (Odocoileus virginianus) on the prevalence of bovine tuberculosis in the Michigan wild deer population.

A retrospective study was conducted to test the hypothesis that supplemental feeding of white-tailed deer (Odocoileus virginianus) from 1995 to 1997 was associated with the prevalence of bovine tuberculosis (TB) in free-ranging deer in northeastern Michigan. Bovine TB prevalence data were obtained from an ongoing surveillance program, while data relating to supplemental feeding and other risk factors were collected via in-person interviews. A multivariable Poisson regression modeling approach was used to test the stated hypothesis while controlling for other risk factors. Of the 389 potential participants, 59% agreed to participate in the study. Results showed that supplemental feeding of deer was associated with bovine TB in white-tailed deer. Specific risk factors associated with increasing risk for bovine TB were locating feed sites in areas with high levels of hardwood forests (O.R. = 1.8, 95% C.I. = 1.3-2.4), other large-scale feeding sites in the area (O.R. = 1.1, 95% C.I. = 1.0-1.2), the number of deer fed per year (O.R. = 3.9, 95% C.I. = 1.4-11.4), the numbers of feed sites spreading grain (O.R. = 14.7, 95% C.I. = 2.2-98.9), the quantity of grains provided at the site (O.R. = 1.4, 95% C.I. = 1.1-1.7), and the quantity of fruits and vegetables provided (O.R. = 1.4, 95% C.I. = 1.2-1.7). Conversely, factors associated with decreasing risk of bovine TB were locating feed sites in areas with high levels of hardwood forests (O.R. = 0.1, 95% C.I. = 0.02-0.4), locating feed sites in forests (O.R. = 0.05, 95% C.I. = 0.01-0.4), and the level of sites providing grain (O.R. = 0.1, 95% C.I. = 0.01-0.3). The results of this study suggest that banning the practice of supplemental feeding is a valid policy for control of bovine tuberculosis in free-ranging white-tailed deer.

Bovine tuberculosis in Michigan wildlife.

White-tailed deer in Michigan are now recognized as a reservoir host of bovine tuberculosis (TB). It has been determined that the most likely cause of bovine TB infection in the deer is from congregating in artificially high numbers at feed sites. The presence of a wildlife reservoir of TB in Michigan poses a serious threat to the control and eradication programs that are now in their final stages in the United States.