Animal Digestion Research Articles

Effect of Gamma-Irradiation Dose on the Yield and Acute Toxicity of Seed Potato Tubers of the Meteor Variety

The influence of the dose of presowing γ-irradiation of tubers on the anatomical and morphological structure, yield, and tasting properties of potatoes of the Meteor variety has been studied. Morphological disorders—beak-shaped and heart-shaped tubers of a large fraction and small tubers in the form of embryos—were found in potatoes grown from tubers irradiated with doses of 500–600 Gy, although no external anatomical and morphological differences were noted in the stems and leaves of potato plants in the course of the vegetative development regardless of the presowing irradiation dose of tubers. Irradiation of seed tubers with doses of 200–300 Gy led to the highest yield and profitability and the best tasting qualities of grown potatoes. Experiments on the toxicity of potato tubers irradiated with doses of 100–1500 kGy and juice released during their radiolysis with doses of 1200–5000 kGy showed no negative effect on the animals that consumed them. At the same time, the physiological processes of digestion, excretion, and metabolism in experimental animals were not inhibited and the level of glucose in their blood remained within physiological reference values. The experimentally established highest doses of γ-irradiation of potatoes and the doses of introducing aqueous dispersions of the irradiated products into mice (gram of substance per 1 kg of live weight of the animal) that did not cause clinical manifestations were 10 g/kg for powdered potato tubers irradiated with a dose of 1500 kGy and 20 g/kg for dried juice powder released in the course of irradiation of potato tubers with a dose of 2000 kGy.

Strategies of Climate Change Mitigation in Agriculture Plant Production—A Critical Review

Agriculture is the second-highest, after energy use, source of greenhouse gas emissions, which are released from soils and animal digestion processes and as a result of energy consumption at various stages of agricultural production. However, changes in the management of agricultural systems may mitigate the negative impact of this sector on the atmosphere and climate. This paper presents a literature review on energy consumption in agriculture and the potential of agricultural crop production to assist in mitigation of global warming by increasing absorption of CO2 from the atmosphere. The issue was considered in the context of managing the cultivation of main, catch and cover crops. The potential of carbon sequestration in the above- and below-ground biomass of selected crops was analyzed. It was stated that, depending on the species, main crops can sequester up to 113 CO2 ha−1 yr−1 in whole biomass, while catch or cover crops can sequester up to 14.80 CO2 ha−1 yr−1 and 0.17 CO2 ha−1 yr−1 in the above- and below-ground biomass, respectively. The benefits of the spread of catch or cover crops, such as improvement of soil quality (leading to an increase in primary crop yield by even as much as 65%) and a phytosanitary effect, as well as the barriers that limit the use of catch crops, including the problems with matching crop species to climate and soil conditions and the risk of reducing farmers’ income, were considered. The results of the review show that catch crops can assimilate an additional amount of 4 to 6 tonnes CO2 ha−1 yr−1, and thus, spreading of catch crops is an effective way to reduce the climate impact of agriculture.

You are what you eat-ecological niche and microhabitat influence venom activity and composition in aquatic bugs.

True water bugs (Nepomorpha) are mostly predacious insects that live in aquatic habitats. They use their piercing-sucking mouthparts to inject venomous saliva that facilitates the capture and extra-oral digestion of prey animals, but their venom can also be deployed for defence. In Central Europe, nepomorph species representing different families coexist in the same habitat. However, their feeding ecology, including venom composition and deployment, has not been investigated in detail. We used an integrated proteotranscriptomic and bioactivity-based approach to test whether venom composition and activity differ between four water bug species sharing the same habitat but occupying different ecological niches. We found considerable species-dependent differences in the composition of digestive enzymes and venom components that probably evolved as adaptations to particular food sources, foraging strategies and/or microhabitats. The venom of Corixa punctata differed substantially from that of the three strictly predatory species (Ilyocoris cimicoides, Notonecta glauca and Nepa cinerea), and the abundance of herbivory-associated proteins confirms a mostly plant-based diet. Our findings reveal independent adaptations of the digestive and defensive enzyme repertoires accompanied by the evolution of distinct feeding strategies in aquatic bugs.

Reptilian digestive efficiency: Past, present, and future

Digestion and assimilation of nutrients and energy is central to survival. At its most basic level, investigations of digestion in animals must examine digestive efficiency, or how much of a given meal (i.e., energy) or a specific nutrient an organism can acquire from its food. There are many studies examining this in reptiles, but there is large variation in methodology, and thus, in the conclusions drawn from the gathered data. The majority rely on ratio-based analyses that can jeopardize the reliability of their findings. Therefore, we reviewed the literature to identify common themes in the digestive efficiency data on reptiles. Due to the sheer number of available studies, we largely focused on lizards, but included data on all reptilian groups. As an example of what the current data can reveal, we performed a meta-analysis of digestive efficiency in lizards as a function of temperature using regression analyses. We detected a weak positive trend of soluble carbohydrate digestibility as a function of temperature, but no similar trend in broad-scale digestive efficiency, and propose that these patterns be reevaluated with non-ratio data. We conclude with calls to end conducting analyses on ratios and instead employ covariate methods, for more studies of reptilian digestive efficiency and related processes using consistent methodology, more representation of each population (e.g., many studies focus on males only), and more detailed studies examining the effects of temperature on digestion (since the current data are inconclusive).

Dietary intake of microplastics impairs digestive performance, induces hepatic dysfunction, and shortens lifespan in the annual fish Nothobranchius guentheri.

Microplastics (MPs) are ubiquitous in aquatic and terrestrial ecosystem, increasingly becoming a serious concern of human health. Many studies have explored the biological effects of MPs on animal and plant life in recent years. However, information regarding the effects of MPs on aging and lifespan is completely lacking in vertebrate species to date. Here we first confirm the bioavailability of MPs by oral delivery in the annual fish N. guentheri. We then show for the first time that administration of MPs not only shortens the lifespan but also accelerates the development of age-related biomarkers in N. guentheri. We also demonstrate that administration of MPs induces oxidative stress, suppresses antioxidant enzymes, reduces digestive enzymes, and causes hepatic dysfunction. Therefore, we propose that administration of MPs reduces lifespan of N. guentheri via induction of both suppressed antioxidant system and digestive disturbance as well as hepatic damage. Our results also suggest that smaller MPs appear more toxic to digestion, metabolism and growth of animals.

Microbiome lodgers help protect tadpoles from climate change

Most creatures are essentially mobile cities, inhabited by hundreds of species of friendly gut bacteria and microorganisms, which contribute to each animal's digestion and wellbeing. ‘Housing microbes in the gut can help animals perform better, like growing faster and reproducing more’, says Samantha Fontaine from the University of Pittsburgh, USA. In return for sanctuary, these internal microbial communities – known as gut microbiomes – also appear to provide protection for coldblooded (ectothermic) hosts from the damaging effects of high temperatures, which these species are experiencing increasingly as the planet warms. Having previously discovered that green frog (Lithobates clamitans) tadpoles struggle more with warmth when their gut microbiome is less diverse, Fontaine and Kevin Kohl (University of Pittsburgh) wanted to find out how the reduction in their microbial lodgers impacts the tadpoles’ ability to weather warm conditions.After collecting pairs of adult green frogs from the University of Pittsburgh's field station, Fontaine and Kohl returned to the lab where they induced a pair of adults to mate, before transferring the freshly laid frogspawn into sterile pondwater to develop into tadpoles. ‘Keeping the eggs in a sterilized environment allows us to better control the microbial environment the tadpoles are exposed to, so we can attribute any changes we see in their physiology later in life to the different water conditions’, says Fontaine. Then she transferred half of the tadpoles into an unsterilized pondwater mixture – teaming with microbial life – where the young amphibians could develop a strong gut microbiome, while their siblings remained unexposed to microbes in sterilised pondwater – developing a depleted microbiome – before allowing the animals to grow at a comfortable 22°C until 9 weeks old. Fontaine then tested their resilience to a heatwave by transferring tadpoles from both groups to warm water (32°C) for 1 day, before collecting the youngsters’ intestines, to find out which genes the two groups of tadpoles had activated during the warm spell, in addition to finding out how their gut microbiomes responded to the blast of warmth.Initially, when the duo compared gene expression patterns between the gut tissue of tadpoles carrying a more complex, natural, microbiome and those with a depleted microbiome before the heatwave, there was little difference between the two. The duo concluded that carrying any microbiome is better for the tadpoles’ general wellbeing than none at all. In addition, the heatwave impacted the gut tissue gene expression patterns of all of the tadpoles. However, the tadpoles with the depleted microbiome reacted most strongly, with the largest gene expression changes to the hot day. Instead of being protective, these massive increases in gut tissue gene expression appear to be detrimental to the youngsters’ health, possibly because the tadpoles with the depleted microbiome were under more stress.Moving on to compare the gene pools of the microbiomes, it was clear that at higher temperatures the tadpoles that were colonised with a diverse microbiome had a head start over those with a depleted microbiome; the more natural microbiome altered the prevalence of genes involved in amino acid and protein production, carbohydrate digestion and energy production, which seemed to provide their tadpole hosts with some protection from the heat. In contrast, the depleted microbiome of tadpoles from sterile pondwater didn't respond at all to the increased temperature, leaving the tadpole hosts poorly prepared as the mercury soared. The more diverse, natural microbiome was protecting the tadpoles from the damaging heatwave.In short, a tadpole's ability to withstand the heat is probably the sum of the tadpole and its microbial lodgers’ protective contributions, and Fontaine says, ‘As global temperatures continue to rise, it will be important to incorporate host–microbe interactions into our understanding of host responses to climate change’.

Assessment of nutrient digestibility in four dry dog foods containing different levels of protein, fat and carbohydrate

A study was undertaken in switch over design to find out the effects of four different treatment combinations of protein, fat and carbohydrates in dry dog foods on the apparent digestibility of nutrients. Four medium sized healthy adult nondescript dogs of about one to two years of age and around 10 to 15 kg body weight were selected and allotted to four dietary treatments- T1 (40 per cent CP, 23 per cent fat, 30 per cent carbohydrate and 3626 kcal ME), T2 (35 per cent CP, 20 per cent fat, 38 per cent carbohydrate and 3528 kcal ME), T3 (26 per cent CP, 15 per cent fat, 52 per cent carbohydrate and 3475 kcal ME) and T4 (20 per cent CP, 11 per cent fat 62 per cent carbohydrate and 3370 kcal ME). The feeding trial was conducted in switch over model of design with one week in between the periods to nullify carry over effect. Results revealed that levels of nutrients in diet had a significant influence on nutrient digestibility in the experimental animals. Among the dietary treatments, T1 with higher fat and protein levels had better dry matter digestibility while T3 diet containing 26 per cent protein, 15 per cent fat and 52 per cent carbohydrate had better crude protein and ether extract digestibility, hence can be recommended.

Digestibility, Blood Parameters, Rumen Fermentation, Hematology, and Nitrogen Balance of Goats after Receiving Supplemental Coffee Cherry Pulp as a Source of Phytochemical Nutrients.

Simple SummaryCoffee pulp is a typical byproduct in nations where coffee is cultivated, particularly Thailand. Such phytonutrients as tannin, saponin, and chlorogenic acid are abundant in this residue. Ruminants’ rumen fermentation and feed utilization may both be improved by these substances. Our study demonstrates that feeding goats coffee pulp improved animal digestibility and rumen fermentation activity without affecting feed intake or blood metabolite levels.This research examines the impact of adding dried coffee cherry pulp (CoCP) to goat feed on the digestibility of the feed, rumen fermentation, hematological, and nitrogen balance. A goat feeding experiment employed four male crossbreds (Thai Native × Anglo Nubian) aged 12 months and weighing 21.0 ± 0.2 kg each. The treatment was conceived as a 4 × 4 Latin square with four specific CoCP levels at 0, 100, 200, and 300 g/day. Dry matter intake (DMI), organic matter intake (OMI), and crude protein intake (CPI) were unaffected by the addition of CoCP. However, across treatment groups, there was a linear increase in ether extract intake (EEI) (p < 0.01), neutral detergent fiber intake (NDFI) (p = 0.06), and acid detergent fiber intake (ADFI) (p = 0.04), as well as a quadratic effect on DMI% BW (p = 0.04). The findings showed that rumen temperature, pH, ammonia-nitrogen, or pack cell volume did not change with CoCP supplementation. Total volatile fatty acid showed linear effects on acetate (p = 0.03) and was quadratically affected by propionate concentration (p = 0.02), acetate to propionate ratio (p = 0.01), acetic plus butyric to propionic acid ratio (p = 0.01), and methane estimation (p = 0.01). With increased CoCP supplementation, there was a linear decrease in protozoa count by about 20.2% as the amount of CoCP supplemented increased (p = 0.06). CoCP supplementation in animal feed resulted in a linear decrease in urinary nitrogen (p = 0.02) and a quadratic effect on absorbed nitrogen (p = 0.08) among treatment groups, with greater N utilization values found in goats fed 200 g/d CoCP. In light of this, supplementing CoCP into animal feed may improve animal digestion and rumen fermentation effectiveness while having no effect on feed intake, rumen microbes, or blood metabolites.

Supplemental Enzyme and Probiotics on the Growth Performance and Nutrient Digestibility of Broilers Fed with a Newly Harvested Corn Diet.

Simple SummaryAs an important energy feed material for livestock and poultry, corn is often in short supply and used immediately after harvest. However, newly harvested corn can have anti-nutritional factors (ANFs) and cause animal diarrhea. Feed-grade enzymes and probiotics can help to alleviate ANFs in feedstuffs. Therefore, in this study, several enzymes and a laboratory Pediococcus acidilactici BCC-1, isolated from chick ceca, were added into the newly harvested corn diet for a 21-day trial in broilers. Here, we found that the newly harvested corn diets resulted in shorter digesta emptying time, increased visual fecal water content, and decreased trypsin activity, which may lead to the occurrence of diarrhea in broilers. The supplementation of Pediococcus acidilactici BCC-1 to newly harvested corn diets could improve the activity of trypsin and decrease the FCR (F/G) of broilers. Moreover, supplemental protease could significantly increase the digesta emptying time, reduce the visual fecal water content, and increase trypsin activity, which may relieve the diarrhea of broilers. In conclusion, Pediococcus acidilactici BCC-1 or protease individually, as well as in combination with glucoamylase are recommended in newly harvested corn diets for broilers.A new grain phenomenon happens in newly harvested corn because of its high content of anti-nutritional factors (ANFs), which can cause low nutrient digestibility and diarrhea in animals. Enzymes and probiotics have been shown to relieve the negative effect of ANFs for animals. The purpose of this study was to investigate the effect of enzymes and probiotics on the performance and nutrient digestibility of broilers, fed with newly harvested corn diets. A total of 624 Arbor Acres Plus male broiler chickens were randomly divided into eight treatment groups (A: normal corn diet, CT: newly harvested corn diet, DE: newly harvested corn diet + glucoamylase, PT: newly harvested corn diet + protease, XL: newly harvested corn diet + xylanase, BCC: newly harvested corn diet + Pediococcus acidilactici BCC-1, DE + PT: newly harvested corn diet + glucoamylase + protease, XL + BCC: newly harvested corn diet + xylanase + Pediococcus acidilactici BCC-1). Each group was divided into six replicates, with 13 birds each. On day 21, growth performance, nutrient digestibility, and digestive enzyme activity were measured. Compared with the normal corn diet (PC), the newly harvested corn diet (NC) produced shorter digesta emptying time (p = 0.015) and increased visual fecal water content (p = 0.002) of broilers, however, there was no effect on performance. Compared to the newly harvested corn diet (NC), supplemental enzyme of DE increased the activity of chymotrypsin (p = 0.016), however, no differences in the digestibility of three kinds of organic matter, digesta emptying time, visual fecal water content, or performance were found. Supplemental protease (PT) significantly increased digesta emptying time (p = 0.004) and decreased the activity of maltase (p = 0.007). However, it had no effect on the digestibility of three kinds of organic matter or the performance of broilers. Supplemental xylanase (XL) decreased the activity of amylase (p = 0.006) and maltase (p < 0.001); however, it had no effect on digesta emptying time, visual fecal water content, the digestibility of three kinds of organic matter, or performance of broilers. Supplemental DE, combined with PT (DE + PT), increased the digesta emptying time (p = 0.016) while decreasing the visual fecal water content (p = 0.011), and the activity of amylase (p = 0.011), lipase (p = 0.021), and maltase (p < 0.001), however, there was no effect on performance. Supplemental BCC individually decreased the activity of amylase (p = 0.024) and maltase (p < 0.001), however, it increased the activity of trypsin (p < 0.001) and tended to improve feed conversion ratio (FCR) (p = 0.081). Supplemental BCC-1, combined with XL (XL + BCC), increased the activity of trypsin (p = 0.001) but decreased the activity of amylase (p = 0.013), lipase (p = 0.019), and maltase (p < 0.001). Pediococcus acidilactici BCC-1 (109 cfu/kg), protease (800,000 U/g) individually, or protease (800,000 U/g) in combination with glucoamylase (800,000 U/g) were supplemented in newly harvested corn diets for growing broilers. Hence, this study mainly explores the alleviation effect of enzyme and probiotics on the negative phenomenon caused by the utilization of newly harvested corn in broilers and provides a better solution for the utilization of newly harvested corn in production practice.

Sheep fecal transplantation affects growth performance in mouse models by altering gut microbiota.

Animal growth traits are important and complex traits that determine the productivity of animal husbandry. There are many factors that affect growth traits, among which diet digestion is the key factor. In the process of animal digestion and absorption, the role of gastrointestinal microbes is essential. In this study, we transplanted two groups of sheep intestinal microorganisms with different body weights into the intestines of mice of the same age to observe the effect of fecal bacteria transplantation on the growth characteristics of the mouse model. The results showed that receiving fecal microbiota transplantation (FMT) had an effect on the growth traits of recipient mice (P < 0.05). Interestingly, only mice receiving high-weight donor microorganisms showed differences. Use 16S rDNA sequencing technology to analyze the stool microorganisms of sheep and mice. The microbial analysis of mouse feces showed that receiving FMT could improve the diversity and richness of microorganisms (P < 0.05), and the microbial composition of mouse feces receiving low-weight donor microorganisms was similar to that of the control group, which was consistent with the change trend of growth traits. The feces of high-weight sheep may have higher colonization ability. The same five biomarkers were identified in the donor and recipient, all belonging to Firmicutes, and were positively correlated with the body weight of mice at each stage. These results suggest that FMT affects the growth traits of receptors by remodeling their gut microflora.

Pinworms are Associated with Taxonomic But Not Functional Differences in the Gut Microbiome of White-Throated Woodrats (Neotoma albigula)

Vertebrates rely on their gut microbiome for digestion, and changes to gut microbial communities can impact host health. Past work, primarily in model organisms, has revealed that endoparasites disrupt the gut microbiome. Here, using wild-caught white-throated woodrats (Neotoma albigula), we tested whether naturally acquired parasite infections are associated with different microbiome structure and function. We surveyed wild N. albigula in eastern Utah for gastrointestinal parasites in the spring and fall of 2019, using traditional fecal float methods and testing a PCR-based approach to detect infection. We tested whether the host gut microbiome structure and function differed based on infection with the most prevalent parasite, the pinworm Lamotheoxyuris ackerti. In spring, infected and uninfected animals had significantly different microbiomes, but these differences were not detected in the fall. However, for both sampling periods, infection was associated with differences in particular microbial taxa determined by differential abundance analysis. As N. albigula rely on their microbiomes to digest both fiber and the plant defensive compound oxalate, we compared microbiome function by measuring dry matter digestibility and oxalate intake in infected and uninfected animals. Although we expected infected animals to have reduced fiber degradation and oxalate intake, we found no difference in microbiome function using these assays. This work suggests that parasite effects on the microbiome may be difficult to detect in complex natural systems, and more studies in wild organisms are warranted.

The role of dietary plant and animal protein intakes on mitigating sarcopenia risk.

Purpose of reviewTo highlight contemporary findings comparing the digestibility of animal and plant proteins, their stimulatory effects on muscle protein synthesis, and associations with sarcopenia.Recent findingsAnimal proteins are more digestible than plant proteins, resulting in greater amino acid availability and stimulation of muscle protein synthesis. However, isolated plant proteins, plant protein blends, and modified plant proteins enriched with indispensable amino acids can elicit comparable digestion and absorption kinetics to animal proteins. More research is needed to determine whether these modified plant protein sources can effectively mitigate sarcopenia risk.SummaryBoth animal and plant protein foods can be incorporated into a healthful eating plan that limits risk of age-related diseases, such as sarcopenia. Humans eat food rather than isolated nutrients; as such, considering the context of the overall diet and its impact on health, instead of solely focusing on individual nutrients in isolation, is important.

From the President and IFST News

From the President and <scp>IFST</scp> News

Particle size distribution, energy consumption, nutrient composition and in vitro ileal digestion characteristics of hammer milled maize and soybean meal affected by moisture content

Grinding is an important feed processing technology, determining physical and nutritional characteristics of ground materials, which affects nutrient digestion in animals and their growth performance. This study aimed to clarify if differences in moisture content (MC) lead to differences in nutrient composition over various particle size fractions after grinding that have potential to affect feed manufacturing characteristics or animal performance. Maize and soybean meal (SBM) with targeted MC of 120, 140 and 160 g/kg (adding no (0), 30 and 60 g/kg of tap water, respectively) were hammer-milled and the physical and chemical characteristics as well as in vitro apparent ileal digestibility (AID) of particle size fractions were determined. The mill was fitted with a 6-mm (maize) or 2-mm (SBM) sized screen, with milled material subsequently separated by dry sieving (size ranging from < 0.075 to > 3.36 mm) and each fraction was analyzed for its nutrient composition, morphology characteristics and in vitro AID of organic matter (OM) and crude protein (CP). For the latter assay, specific particle size fractions were additionally ground using a laboratory mill (1 mm screen). Geometric mean particle size diameter and energy consumption increased with increasing MC (P < 0.05). Chemical composition, physical characteristics and in vitro AID of particle size fractions were significantly different (P < 0.001). Moisture addition had no significant effect on nutritional and physical parameters except for solidity in maize, ash content, projected area, circularity, and solidity in SBM. Physical characteristics of particles, especially particle size affected in vitro AID of OM and CP most (P < 0.05). Additional grinding of samples before determination of in vitro AID increased the OM digestibility up to 0.684 in maize (P < 0.001). Additional grinding of particles larger than 0.595 mm increased in vitro AID of OM and CP (P < 0.05). In summary, increasing MC has limited effect on the breakage behavior of maize and SBM, but increased energy consumption during hammer-milling. In vitro AID measurement of fractionated particles appears to require material should be ground to pass a 0.595 mm sieve rather than the prescribed 1 mm.

Effect of Two Soybean Varieties Treated with Different Heat Intensities on Ileal and Caecal Microbiota in Broiler Chickens.

Simple SummarySoybeans are an essential part of today’s poultry nutrition diets because of their high protein content and quality. To ensure optimum digestibility in monogastric animals, soybeans need to be thermally processed. As required heat intensities depend on individual soybean properties, the emergence of highly heterogenic soybean batches is a challenge for adequate processing conditions. Molecular changes occurring during heat treatment can alter the microbial communities colonizing the animals’ guts. Gut microbiota is of great importance for both its host animal’s performance and health. To investigate the effect of heat treatment and soybean variety on the chickens’ microbiota, two soybean varieties were selected, treated at two different heat intensities and subjected to a feeding trial. DNA was then extracted and sequenced to identify different bacterial populations in the digesta of certain gut sections. Results showed that both the soybean variety and the applied heat treatment affected the abundance of certain bacterial species in the gut of chickens, but no effect on the taxonomy level of family or genus appeared. This underlines the sensitivity and reactivity of the highly complex microbial community to apparently small dietary differences.Soybean products are of high importance for the protein supply of poultry. Heat treatment of soybeans is essential to ensure optimal digestibility because of intrinsic antinutritive factors typical for this feed category. However, excessive treatment promotes the Maillard reaction and reduces protein digestibility. Furthermore, Europe’s efforts are to decrease dependence on imports of soybean products and enlarge local production. This process will include an increase in the variability of soybean batches, posing great challenges to adequate processing conditions. Intrinsic soybean properties plus heat treatment intensity might be able to modulate the gut microbiota, which is of crucial importance for an animal’s health and performance. To assess the influence of heat treatment and soybean variety on gut microbiota, 2 soybean cakes from 2 varieties were processed at 110 °C or 120 °C and subsequently fed to 336 one-day-old broiler chickens. After 36 days, the animals were slaughtered, and the digesta of the ileum and caecum was collected. Next, 16S rRNA amplicon sequencing of the extracted DNA revealed a high discrepancy between gut sections, but there were no differences between male and female birds. Significant differences attributed to the different soybean varieties and heat intensity were detected for certain bacterial taxa. However, no effect on specific families or genera appeared. In conclusion, the results indicated the potential of processing conditions and soybean variety as microbiota-modulating factors.

Genomic Insights into the Distribution of Peptidases and Proteolytic Capacity among Prevotella and Paraprevotella Species.

ABSTRACTBacterial peptidases play important roles in health and nutrient digestion in both humans and animals, especially ruminant animals. In this study, we examined and compared the various peptidases (both total and secretory) among species of Prevotella (44 in total) and Paraprevotella (2) revealed in their sequenced genomes that were archived in the MEROPS database. The phylogenetic relationships were also compared among the species based on 16S rRNA gene sequences and the occurrence of peptidases. A rich repertoire of peptidases was found that represents six catalytic types of peptidases (aspartic, cysteine, glutamic, metallo, mixed, and serine), together with some with unknown catalytic mechanisms, and 78 families. Metallopeptidases were the most predominant, followed by serine and cysteine peptidases. Considerable variations in peptidase occurrence and distribution were noted among the species and the different families of peptidases. A total of 48 different families of secretory peptidases were found in the genomes of the Prevotella and Paraprevotella species. Secretory peptidases in the families of S41 and M13 were ubiquitous, and S9, M16, C1, S13, and C69 were found in more than 95% of the species. Multivariate analysis of the peptidases indicated that species were mostly clustered except for a few species. Analysis using a bipartite association network showed that the majority of peptidase families were shared among the species. The relatedness of peptidase distributions among the species did not significantly correlate with their phylogenetic relationship based on the 16S rRNA genes. The genomic overview on the peptidases of Prevotella and Paraprevotella species provided new insights into their potential capacity to degrade proteins.IMPORTANCE Species of Prevotella are prevalent and predominant bacteria residing in animals and humans, and their proteolytic capacity and activity play important roles in nutrient utilization in animals (especially ruminants) and some anaerobic infections of the intestinal, respiratory, and urinary tracts in humans. This study reveals the large repertoire and wide distribution of metallo, serine, and cysteine peptidases, especially secretory peptidases, among the Prevotella species. The information presented here could aid in the identification of the Prevotella species and the peptidases to target to decrease the excessive protein degradation in the rumen and improve dietary nitrogen utilization by ruminant animals.

The release and catabolism of ferulic acid in plant cell wall by rumen microbes: A review.

Ferulic acid (FA) is one of the most abundant hydroxycinnamic acids in the plant world, especially in the cell wall of grain bran, in comparison with forage and crop residues. Previous studies noted that FA was mainly linked with arabinoxylans and lignin in plant cell walls in ester and ether covalent forms. After forages were ingested by ruminant animals or encountered rumen microbial fermentation in vitro, these cross-linkages form physical and chemical barriers to protect cell-wall carbohydrates from microbial attack and enzymatic hydrolysis. Additionally, increasing studies noted that FA presented some toxic effect on microbial growth in the rumen. In recent decades, many studies have addressed the relationships of ester and/or ether-linked FA with rumen nutrient digestibility, and there is still some controversy whether these linkages could be used as a predicator of forage digestibility in ruminants. The authors in this review summarized the possible relationships between ester and/or ether-linked FA and fiber digestion in ruminants. Rumen microbes, especially bacteria and fungi, were found capable of breaking down the ester linkages within plant cell walls by secreting feruloyl and p-coumaroyl esterase, resulting in the release of free FA and improvement of cell wall digestibility. The increasing evidence noted that these esterases secreted by rumen microbes presented synergistic effects with xylanase and cellulase to effectively hydrolyze forage cell walls. Some released FA were absorbed through the rumen wall directly and entered into blood circulation and presented antioxidant effects on host animals. The others were partially catabolized into volatile fatty acids by rumen microbes, and the possible catabolic pathways discussed. To better understand plant cell wall degradation in the rumen, the metabolic fate of FA along with lignin decomposition mechanisms are needed to be explored via future microbial isolation and incubation studies with aims to maximize dietary fiber intake and enhance fiber digestion in ruminant animals.

Biochemical changes associated with the administration of aqueous pulp extract of Irvingia gabonensis fruit on adult male Wistar rats

Biochemical changes associated with the administration of aqueous pulp extract of Irvingia gabonensis fruit on adult male Wistar rats

Hegel's Dialectics of Digestion, Excretion, and Animal Subjectivity

In the Philosophy of Nature, Hegel describes at length and in detail the particular workings of animal digestion and excretion, referring to the empirical research of his day (Berzelius, Spallanzani, Traviranus). By becoming engaged in the scientific disputes and insights of the time—regarding, for example, the mechanical versus chemical nature of digestion, immediate digestive assimilation and the chemical composition of feces—Hegel arrives at the novel idea that what the animal excretes as superfluous is its own particular entanglement with inorganic otherness. The animal’s subsequent feeling of triumph and satisfaction constitutes the affirmation of individual purposiveness, a form of immediate ideality that Hegel presents as animal subjectivity.

Gryllus testaceus walker (crickets) farming management, chemical composition, nutritive profile, and their effect on animal digestibility

AbstractCommonly, the life span of the cricket is very short, reaching from 60 to 70 days and the average egg production lies within the range of 200–1,500 eggs/female. The female can mate with many males and can produce more fertile eggs. The body composition of an adult cricket on analysis showed that it contains dry matter 33.30%, crude protein 63.30%, crude fat 5.20%, ash 5.60%, calcium 10.10%, phosphorous 7.90%, zinc 215.0 mg/kg, and copper 15.00 mg/kg on dry matter basis, respectively. The dry matter digestibility diet was highest for whole cricket (WC, with legs) and the digestibility of ash, crude fiber, and crude fat was higher than form body cricket (BC, removal of legs). The WC and BC diets had lower feed conversion rates than control diets, and higher nitrogen retention (digestion). It was concluded that crickets are potential feed ingredients for ruminants and non‐ruminants, especially as protein supplements methane emissions are low in vitro and high ash digestibility indicates the ability to reduce mineral deficiencies.