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At least 19 recordsLinked to original sources

PubMed2026

Genome-wide association studies for feed efficiency, production and feeding behavior traits in Canadian purebred Duroc pigs.

This study aimed to identify potential genetic variants and candidate genes associated with feed efficiency (FE), production, and feeding behavior traits in Canadian purebred Duroc pigs. Genome-wide association studies (GWAS) were conducted using 8,861 individuals and an imputed Affymetrix PigGen Canada 50K panel v2.0 using a linear mixed model (LMM) and a Bayesian B model. This analysis used an adjusted P-value threshold (ranging from 6.6 × 10-5 to 1.3 × 10-4) using a false-discovery rate to determine significance. The number of significant SNPs identified for each trait was as follows: average daily gain (ADG, 48), daily feed intake (DFI, 85), feed conversion ratio (FCR, 101), residual feed intake (RFI, 37), residual gain (RG, 64), residual intake and gain (RIG, 55), backfat thickness (BF, 100), loin depth (LD, 6), Kleiber's ratio (KR, 0), total time spent eating per day (TPD, 7), and number of visits to the feeder per day (NVD, 6). Several traits (BF, DFI, FCR, RFI, RG, and RIG) showed strong overlapping signals on chromosomes 7 and 10 with 24 shared significant SNPs, indicating potential shared genetic mechanisms. These traits also had 71 overlapping candidate genes, such as PACSIN1, PTCH1, ADIPOR1, and ITPR3, associated with glucose, lipid, and cholesterol metabolism. Well-known candidate genes in literature associated with growth and fatness such as MC4R and CDH20 were also identified to be associated with ADG, BF, FCR, and DFI in this study. Gene ontology enrichment analysis revealed that a set of the candidate genes were involved in the gonadotropin-releasing hormone (GnRH) and the platelet-derived growth factor (PDGF) signaling pathways. Overall, this study contributed to understanding the genetic architecture and provided a biological foundation for improving FE, production, and feeding behavior traits in Canadian Duroc pigs, facilitating the selection of more efficient pigs.

Sus scrofa↗

PubMed2026

Bayesian Genome-Wide Association Study of Feed Efficiency Traits in Pigs.

Feed efficiency traits are increasingly important in pig production for improving profitability and environmental sustainability. Understanding their genetic basis is crucial for uncovering underlying biological mechanisms and informing selection strategies. In this study, we analyzed residual feed intake (RFI), feed conversion ratio (FCR), and average daily feed intake (ADFI) in 201 animals. Three separate Bayesian GWASs were conducted using 29,844 SNPs in a case-control design, with the lowest and highest 15% of the phenotypic distribution selected as controls and cases (N = 30 per group), respectively, for each trait. The results confirmed the polygenic nature of the traits, identifying 4 SNPs for RFI on Sus scrofa chromosomes (SSC) 3, 13, and 15 with high posterior probability for the direction of their effects; 4 SNPs for FCR on SSC 8, 14, and 17; and 8 SNPs for ADFI on SSC 1, 2, 6, 8, and 11. A candidate gene search identified 41 potential genes involved in diverse biological processes, including feed efficiency, intestinal development, tissue remodeling and integrity, nutrient transport and absorption, metabolic homeostasis, cellular signaling, energy sensing, and neurological regulation. These genes formed a highly interconnected network, highlighting the complexity of feed efficiency and the interplay among multiple physiological, metabolic, and regulatory pathways.

Bayesian analysis↗

PubMed2026

Genome-wide cis-expression Quantitative Trait Loci (eQTL) and transcriptomic signals reveal distinct molecular regulation across correlated feed efficiency traits.

INTRODUCTION: Feed efficiency (FE) is a complex trait which determines livestock production profitability, yet the molecular mechanisms behind it remain unclear. This study investigated the blood transcriptomic profile of lambs, alongside genotype data with the aim to uncover the genetic basis of FE traits such as absolute dry matter intake (DMIabsolute), DMI adjusted for body size (DMIadjusted), average daily live weight gain (ADG), and residual feed intake (RFI). MATERIALS AND METHODS: Bulk RNA-Seq and genotype data were analysed using three complementary approaches: differential gene expression (DGE) analysis, weighted gene co-expression network analysis (WGCNA), and cis-expression Quantitative Trait Loci (cis-eQTL) mapping. These methods were used independently to identify genes and regulatory networks associated with FE traits and to investigate evidence supporting multi-trait candidate gene selection. RESULTS: DGE analysis revealed 2, 24, 85 and 4 differentially expressed genes for DMIabsolute, DMIadjusted, ADG, and RFI (Padjusted < 0.05), functionally enriched in sensory perception, ATP-dependent chromatin remodeling, Notch signaling and immune response pathways. 9 gene modules significantly associated with the FE traits (P ≤ 0.05) with correlations ranging from r = -0.56 to 0.49, were identified using WGCNA. Single nucleotide polymorphism (SNP)-level cis-eQTL analysis identified 93 eSNPs associated with 74 genes (false discovery rate (FDR) < 0.05), while permutation-derived gene level analysis identified 280 eGenes (FDR < 0.2, empirical P < 0.03). Across the three analyses, applying thresholds of DGE (Padjusted < 0.05), WGCNA (correlation, P ≤ 0.05), and cis-eQTL gene-level significance (empirical P < 0.05), multiple overlapping genes were identified including DNMT3A, KANSL1, NCOR1 for DMIadjusted, ACOX2, FANCF, CIMIP2B, LOC101115106, ARMH2, LOC132657496 for ADG, and LOC114114576 for RFI representing regulators of variations in FE. DISCUSSION: The integration of DGE, WGCNA, and cis-eQTL analyses identified key genes and regulatory mechanisms associated with variation in FE traits. These results highlight that integrated multi-trait candidate gene identification approaches can reveal key genes that lower feed intake while maintaining animal growth, supporting breeding strategies aimed at improving efficiency and long-term economic sustainability in sheep.

average daily gain (ADG)↗

PubMed2026

Ruminosignatures associated with methane emissions and feed efficiency across geographies and cattle breeds.

The cattle rumen microbiota represents a complex and dynamic ecosystem whose organization and relationship to host phenotypes are important for food security and environmental sustainability. We analyzed rumen microbiota profiles from 2496 cattle representing five breeds and production systems across five countries, identifying microbial co-abundance groups termed Ruminosignatures. We detected 14 distinct Ruminosignatures, including 2 observed across all populations dominated by Prevotella and UBA2810. Additional Ruminosignatures showed breed- and diet-specific patterns and collectively explained 96%-99% of variance in rumen microbial composition. Integrative cross-country analysis confirmed 10 out of 14 Ruminosignatures identified in cohort-specific analyses. Several Ruminosignatures were associated with methane emissions and feed efficiency traits and were partially under host genetic control, with heritability estimates ranging from 0.09 to 0.58. Structural equation modeling revealed consistent negative genetic and phenotypic correlations between the UBA2810-dominated Ruminosignature (RS_UBA2) and methane emissions across cohorts (rg = -0.40 to -0.65), with structural coefficients concordant in sign across all populations, supporting the expected direction of phenotypic response to selection on RS_UBA2. Meta-analysis confirmed positive associations of RS_UBA2 with average daily gain and negative associations with methane-related traits and feed conversion ratio. Functional genome-based predictions suggested RS_UBA2 may reduce methanogenesis through alternative hydrogen utilization pathways competing with methanogenic archaea. Production system type influenced both Ruminosignature occurrence and relationships with host phenotypes, emphasizing the relevance of context-specific strategies for microbiome modulation. Our findings highlight the potential of the Ruminosignatures framework for microbiome-informed breeding programs aimed at improving feed efficiency while reducing the environmental impact of cattle production.

Animals↗

PubMed2026

Bacteria and phage consortia modulate cecal SCFA production and host metabolism to enhance feed efficiency in ducks.

BACKGROUND: The gut microbiota influences poultry health, nutrition, feed efficiency (FE), and overall productivity. However, the relationship between gut microbes, including bacteria and phages, and FE in ducks remains underexplored. To address this, we integrated cecal 16S amplicon, metagenome, microbiota-derived short-chain fatty acids (SCFAs) profiling, liver transcriptome, and serum metabolome data to illustrate the contribution of the gut microbiome (bacteria and viruses) to duck FE. RESULTS: We reconstructed viral genomes and prokaryotic metagenome-assembled genomes (MAGs) and annotated their genes using comprehensive databases. Prokaryotic hosts of viruses were also predicted to understand virus-host dynamics within the gut ecosystem. Our results revealed that high-FE ducks have higher concentration of propionate and butyrate in cecum compared with low-FE ducks. The metagenome sequencing revealed distinct cecal microbiota profiles between two groups, with increased relative abundance of representative SCFA producers, especially Paraprevotella sp905215575 and Bacteroides sp944322345, and enhanced SCFA-biosynthesis pathways in high-FE ducks. Virome genome assembly identified two phages encoding auxiliary metabolic genes (AMGs) involved in pyruvate metabolism, enhancing nutrient availability for host bacteria to produce SCFAs (e.g., temperate phage-encoded pyruvate phosphate dikinase) or exploiting host central metabolic pathways for viral replication (e.g., lytic phage-encoded formate C-acetyltransferase). Furthermore, these representative SCFA-producing bacteria and phage consortia were associated with serum metabolites (including L-histidine and 4-hydroxydecanedioylcarnitine) linked to duck FE. CONCLUSION: Collectively, these findings provide novel insights into the gut microbial factors regulating FE in ducks, offering potential strategies to optimize poultry nutrition and productivity. Video Abstract.

Animals↗

PubMed2026

Investigating mechanisms of divergent feed efficiency in dairy cows.

Objectives were to investigate the associations between residual DMI (RFI), calculated as the difference between observed minus predicted DMI, with rumen microbiome, digestion, behavior, and metabolism that might explain the differences in RFI in lactating cows. One hundred 50 genotyped Holstein cows in 3 cohorts were used in this cohort study in which exposure was RFI. Rumen microbiota from 114 cows were sequenced, and a subset of 30 cows was used for hepatic mitochondrial respiration analysis. Cows were ranked by RFI and grouped into quartiles (Q1, most efficient, to Q4, least efficient) according to phenotypic (pQ) or genomic (gQ) quartiles of RFI for data presentation. Statistical models fitted the linear and quadratic RFI as continuous explanatory variables. Increasing efficiency, i.e., from larger to smaller RFI values, whether phenotypic or genomic, were associated with reduced DMI, a 3.0 kg/d difference between Q4 and Q1 according to phenotypic RFI (pRFI) and 1.9 kg/d according to genomic RFI (gRFI) without compromising ECM or body tissue reserves. These differences between Q4 and Q1 of pRFI and gRFI resulted in increased feed conversion ratio by an additional 200 and 100 g of ECM/kg DMI, respectively. Both pRFI and gRFI were associated with FA profiles in milk fat, with decreasing proportions of de novo and mixed FA and increasing proportions of pre-formed FA, particularly monounsaturated FA, as efficiency improved. Additionally, pRFI and gRFI were moderately correlated (r = 0.48) and ranking of cows was consistent across the 2 grouping methods (ρ = 0.44). Reducing RFI was associated with less total rumination time, but greater rumination time per kg of DMI by 2.0 and 1.7 min/kg between the extreme quartiles of pRFI and gRFI, respectively. Phenotypically and genomically more efficient cows were associated with less microbial α diversity based on inverse Simpson index. A total of 57 amplicon sequence variant groups were differentially abundant between Q1 and Q4 classified based on pRFI and gRFI, with Prevotella and Succinivibrionaceae shared between phenotypic and genomic RFI classifications. Increasing phenotypic and genomic efficiency was associated with an increased concentration of ruminal NH3-N. Genomically more efficient cows tended to have reduced ruminal pH (gQ1 to gQ4; 6.42 vs. 6.47 vs. 6.43 vs. 6.53) despite eating less. Decreasing pRFI was associated with reduced microbial N yield whereas, it tended to increase microbial N yield relative to the amount of N intake. Collectively, phenotypic and genomic RFI have a moderate degree of agreement matching the estimated heritability of the trait, and mechanisms underlying improved feed efficiency were linked with differences in ruminal microbiota and fermentation, and with increased rumination per kg of DM rather than total-tract digestibility or hepatic mitochondrial respiration.

dairy cow↗

PubMed1976

Generation and compensation of the cancer cachectic process by spontaneous modification of feeding behavior.

Daily food intake and corresponding feeding activity (measured as duration) and feeding efficiency (amount of food ingested per unit of feeding activity) were measured both in normal Sprague-Dawley and Buffalo rats and during growth of Walker 256 and 4M mammary carcinomas in Sprague-Dawley rats and of Morris 5123 hepatoma in Buffalo rats. Estimates of meal size and frequency were also obtained. Growth of the carcinomas produced a decline in feeding activity accompanied, early in tumor growth, by a compensatory increase in feeding efficiency with no resultant effect on food intake. This compensated decline in feeding activity was due to reduction in average meal duration. Later, meal frequency was also reduced, with further reduction in feeding activity and reduction in food intake. There was little change in average meal size. The hepatoma produced a different detailed pattern of effect on feeding behavior. These effects are not nonspecific reactions to foreign tissue. The effects imply behavioral compensation for the breakdown of a rapidly responding physiological control of food intake and can be interpreted in terms of successive impairment of feeding control mechanisms that have different response rates and different behavioral modes.

Animals↗

PubMed2026

Dietary naringenin modulates antioxidant status and hepatic lipid deposition in marine medaka (Oryzias dancena) fed a high-fat diet.

High-fat diets (HFDs) are widely used in aquaculture to improve growth and feed efficiency; however, prolonged feeding can disrupt lipid metabolism, induce oxidative stress, and impair physiological homeostasis. This study evaluated the protective effects of dietary naringenin against HFD-induced physiological alterations in the marine medaka Oryzias dancena. Fish were randomly assigned to one of four dietary treatments and fed the respective experimental diets for 45 days: a normal-fat diet (NFD, 8% crude lipid), a high-fat diet (HFD, 15% crude lipid), or an HFD supplemented with either 0.075% or 0.15% naringenin. Compared with the NFD group, HFD feeding impaired antioxidant status, altered the expression of genes associated with antioxidant defence and lipid metabolism, and promoted hepatic lipid accumulation. Dietary naringenin, particularly at 0.15%, mitigated these adverse effects by restoring muscle superoxide dismutase activity, enhancing total antioxidant capacity, reducing lipid peroxidation, partially normalizing the expression of lipid metabolism-related genes, and alleviating hepatic lipid vacuolation. These findings indicate that dietary naringenin improves antioxidant defence and helps maintain lipid metabolic homeostasis under high-fat feeding conditions, highlighting its potential as a functional dietary additive for aquaculture.

Animals↗

PubMed1979

Characteristics of thyroid function in experimental protein malnutrition.

Two experiments were conducted to study the effects of protein malnutrition on thyroid function. Resting oxygen consumption and serum concentrations of triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH) were measured and correlated with thyroid histology, gain in weight, feed efficiency and carcass energy content in male rats fed isoenergetic diets ad libitum containing 22% (control) or 8% (protein malnourished, PM) casein for 28 or 32 days postweaning. A third group was pair-fed to the PM rats with the control diet. In experiment 2 additional groups were pair-fed to the PM rats with 8% casein diets in which the casein was substituted with different mixtures of carbohydrate and fat. Resting oxygen consumption/body weight (0.75) decreased as body weights increased in all groups, but was consistently greatest in PM rats. In PM rats, plasma T3 was 130% of controls after 11 days of the dietary regimen and averaged 215% of controls from days 18 through 32. In experiment 2 both T3 and T4 concentrations were approximately twice controls in all PM groups. TSH concentrations were within the normal range in all groups throughout. Feed efficiency averaged 36 to 40% of controls and mean weight gain was 30 g after 28 days in the PM groups, compared to 114 and 91 g, respectively, in the pair-fed control rats. Carcass energy content of PM rats after 28 days was significantly lower than in control or pair-fed control rats. Thyroid morphology was compatible with increased secretory activity in all the protein-malnourished groups, compared with normal activity in the control and pair-fed control groups. Thermogenesis, as measured by oxygen consumption, was markedly increased in the PM rats compared to controls. These observations are consistent with a diet-induced thermogenesis in the protein-malnourished rats. In contrast to simple under-nutrition where energy expenditure may be conserved by decreases in thyroid function and thermogenesis, increases in thyroid function and thermogenesis in protein malnutrition could provide an energy balancing mechanism whereby unneeded non-protein energy in the diet could be dissipated as heat, and survival enhanced.

Animals↗

PubMed2026

Fasting-refeeding regimes induce compensatory growth and muscle transcriptomic remodeling in juvenile Qihe gibel carp (Carassius gibelio var. Qihe).

Compensatory growth, an important adaptive response in fish, holds considerable potential for improving feeding efficiency in aquaculture. To identify an optimal fasting-refeeding strategy for juvenile Qihe gibel carp (Carassius gibelio var. Qihe) and to clarify the mechanisms underlying the compensatory growth, we divided two-month-old fish into four groups, namely S0 group (continuous feeding for 28 days), S2 group (4 cycles of 2-day fasting followed by 5-day refeeding), S4 group (fasting for 4 days followed by refeeding for 24 days), and S8 group (fasting for 8 days followed by refeeding for 20 days), then growth performance, muscle tissue morphology, biochemical responses, and muscle transcriptomic profiles under different feeding regimes were investigated. After a 28-day aquaculture experiment, fish in the S4 group exhibited significantly greater body length and weight than those in the S0, S2, and S8 groups, indicating over-compensatory growth. Histological analysis further showed that muscle growth in the S4 group was mainly associated with myofiber hyperplasia. Different feeding regimes also induced distinct changes in hepatic antioxidant and metabolic enzyme activities, as well as intestinal digestive enzyme activities. Transcriptome analysis revealed that the forkhead box O (FoxO) signaling pathway was significantly enriched during compensatory growth. Key genes, including serum/glucocorticoid regulated kinase 1 (sgk1) and insulin receptor substrate 1 (irs1), were predicted to play important roles in this process. Overall, these results indicate that fasting for 4 days followed by refeeding for 24 days (the S4 regime) is the optimal strategy for inducing compensatory growth in juvenile Qihe gibel carp. This study provides new insights into the morphological, physiological, and molecular basis of compensatory growth and offers a scientific foundation for developing efficient and sustainable feeding strategies for this species.

Animals↗

PubMed2026

A Review on Heat Stress in Broiler Chickens: Mechanisms, Effects and Mitigation Strategies.

BACKGROUND: Heat stress (HS) is a major environmental challenge for broilers, particularly under rising global temperatures and high humidity. Broiler chickens are highly susceptible because of their rapid growth rate, high metabolic heat production, limited thermoregulatory capacity and genetic selection for fast growth. OBJECTIVE: This review aims to synthesise current evidence, evaluate the effectiveness of existing mitigation strategies, identify key knowledge gaps and provide future research directions to improve broiler resilience, welfare and productivity under increasingly HS conditions. METHODS: This review synthesised evidence published between 2010 and 2025 on the physiological, metabolic, intestinal, immunological and productive consequences of HS and evaluated mitigation strategies. RESULTS: The reviewed studies demonstrate that HS reduces feed intake by approximately 10%-30%, suppresses body weight gain and feed efficiency and increases mortality, with severity depending on temperature, humidity and broiler genotype. HS disrupts carbohydrate, protein and lipid metabolism; induces acid-base imbalance and oxidative stress; compromises intestinal barrier integrity; alters gut microbiota; suppresses immune function; and reduces meat quality. Nutritional interventions, including dietary electrolyte balance, antioxidants, vitamins, selenium, zinc, phytogenic compounds, probiotics, betaine and optimised feeding strategies, environmental management and genetic approaches, including naked-neck and frizzle genes, can partially alleviate these adverse effects. However, inconsistencies among studies persist because of differences in broiler strains, environmental conditions, dietary formulations and experimental protocols. CONCLUSION: HS substantially compromises broiler health, welfare, productivity and meat quality. Nutritional, environmental and genetic approaches can partially mitigate its adverse effects; however, further research is needed to improve broiler resilience under increasingly HS conditions.

Animals↗

PubMed2025

Nutrigenomics: A tool to unlock genetic potential of Nigerian indigenous goat breeds.

Nigerian indigenous goats represent a valuable genetic resource for meat and milk production. However, their productivity often falls below their genetic potential because of sub-optimal nutrition. Nutrigenomics offers a revolutionary approach to bridge this gap by exploring the interactions between nutrients and goat genes. This study explores how nutrigenomic tools can be used to identify gene variants associated with feed efficiency, meat quality, and milk production. Various technologies are designed to ensure the realization of genetic potential. Nutrigenomics is aimed at exploiting the noncoding section of an individual's genome, which is disregarded in traditional animal nutrient requirement assessment. Nutrigenomic technology has the potential to unlock the genetic potential of animals and essentially help to confront nutritional challenges and sub-optimal use of available feed resources, particularly in Nigerian indigenous goats, of which there is a dearth of information on their nutritional needs and requirements. This review discusses the potential of nutrigenomics to unlock the genetic potential of Nigerian indigenous goats. In addition, the review discusses the challenges and future directions of nutrigenomic research in Nigerian goats. By implementing nutrigenomic strategies, Nigerian goat production can be revolutionized, leading to increased productivity, improved product quality, and enhanced farmer livelihoods. It is hoped that this review will provide vital information to aid research into the nutrigenomics potential of unlocking the genetic potentials and reproductive performance of Nigerian indigenous goats through nutrition.

Animals↗

PubMed1979

Toxicologic studies with sheep fed colored magazines and newsprint.

Paper containing colored inks from magazines and newspapers was fed as 23% of their ration to sheep for 175 days. A similar ration containing oat hulls in place of the paper was fed to control animals. The paper-fed animals consumed 29% more feed than the controls but the feed efficiency (kg animal weight gained/kg ration consumed) of the two rations was approximately equivalent. Lead contained in the paper accumulated in animal tissues. Hepatic microsomal mixed function oxidase activity was several fold higher in the paper-fed animals than the controls. Histopathologic examination of liver and kidney using light and electron microscopy revealed no lesions attributable to diet.

Animal Feed↗

PubMed2026

The current and future perspective of ChickenGTEx project and its applications in precision breeding.

The Chicken Genotype-Tissue Expression (ChickenGTEx) project was established to systematically characterize the regulatory landscape of the chicken genome and to accelerate the translation of functional genomics into precision breeding. By integrating whole-genome sequencing with multi-tissue transcriptomic profiling, ChickenGTEx provides a comprehensive atlas of gene expression regulation across diverse tissues and physiological systems. Current findings demonstrate that complex production traits are governed by coordinated regulatory networks rather than isolated loci, with substantial contributions from tissue-specific gene expression, structural variation, and genotype-by-sex interactions. Sex-dependent regulatory effects further refine the genetic architecture of metabolic, immune, and reproductive traits, highlighting the importance of incorporating sex as a biological variable in genomic analyses. Application of integrative omics frameworks within elite layer populations has revealed multilayer regulatory mechanisms underlying extended laying performance, feed efficiency, metabolic health, and eggshell quality. By partitioning phenotypic variance into genetic, regulatory, and host-microbiome components, these approaches move beyond association-based mapping toward causal inference and biological interpretation. Importantly, validated regulatory loci identified through ChickenGTEx and related analyses provide actionable markers for genomic selection and rational targets for precision genome modification. Looking forward, continued expansion of regulatory atlases, incorporation of single-cell and longitudinal data in diverse environmental conditions, and integration of functional annotation into breeding pipelines will further enhance prediction accuracy and sustainable genetic improvement. The ChickenGTEx project thus represents a foundational platform bridging functional genomics and practical poultry breeding.

Animals↗

PubMed2024

Foraging mechanisms in excavate flagellates shed light on the functional ecology of early eukaryotes.

The phagotrophic flagellates described as "typical excavates" have been hypothesized to be morphologically similar to the Last Eukaryotic Common Ancestor and understanding the functional ecology of excavates may therefore help shed light on the ecology of these early eukaryotes. Typical excavates are characterized by a posterior flagellum equipped with a vane that beats in a ventral groove. Here, we combined flow visualization and observations of prey capture in representatives of the three clades of excavates with computational fluid dynamic modeling, to understand the functional significance of this cell architecture. We record substantial differences amongst species in the orientation of the vane and the beat plane of the posterior flagellum. Clearance rate magnitudes estimated from flow visualization and modeling are both like that of other similarly sized flagellates. The interaction between a vaned flagellum beating in a confinement is modeled to produce a very efficient feeding current at low energy costs, irrespective of the beat plane and vane orientation and of all other morphological variations. Given this predicted uniformity of function, we suggest that the foraging systems of typical excavates studied here may be good proxies to understand those potentially used by our distant ancestors more than 1 billion years ago.

Flagella↗

PubMed2026

In silico genome mining and characterization of putative horse feces-derived bacterial phytases as potential monogastric animal feed additive candidates.

Phytic acid exerts a significant antinutritional effect in poultry, swine, and fish, which can be mitigated by supplementing monogastric feeds with efficient microbial phytases. Accordingly, mining bacterial genomes for novel phytases represents a strategic computational approach to identifying candidates for improving monogastric animal nutrition. In this study, 162 bacterial genomes associated with horse feces were systematically mined using an in silico pipeline to identify and characterize putative phytases.A total of 69 non-redundant sequences were identified and classified as histidine acid phytase (HAPhy) or protein tyrosine phosphatase-like phytase (PTPLPhy). HAPhys were detected in the genomes of Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Acinetobacter baumannii, and Cutibacterium equinum, whereas PTPLPhys were found in K. pneumoniae, Limosilactobacillus reuteri, Pediococcus acidilactici, Bifidobacterium pseudolongum, and Prescottella equi. Principal component analysis identified glucose-1-phosphatase (CAJ1242485.1) and bifunctional acid phosphatase (NHR17779.1) as the HAPhy candidates exhibiting the most favorable predicted physicochemical properties for potential feed applications. Similarly, among the PTPLPhys, protein tyrosine phosphatase (UNQ40438.1) and a hypothetical protein (CAJ1246072.1) showed the most favorable computational profiles. Biosafety analysis identified potential virulence factors, indicating that sources should be screened prior to feed application. High-quality AlphaFold2 models were obtained for these phytases (90.9-97.2). Molecular docking analysis showed that NHR17779.1 exhibited the strongest binding to phytic acid, whereas CAJ1246072.1 demonstrated the weakest interaction. Overall, this study identifies the horse fecal microbiota as a diverse source of putative phytases that may serve as promising targets for genetic and protein engineering; however, further in vitro and in vivo studies are essential to validate the enzymatic activity and industrial efficacy of these computational candidates.

Bacterial phytase↗

PubMed1979

Biochemical changes in avian tissues during infection.

Major sources of error in studies of diet--infectious disease interactions relate to failure 1) to define the stage of a disease cycle; and 2) to determine the extent of disease involvement at time of sampling. The former can be determined from clinical and biochemical observations from time of inoculation to recovery or mortality; the latter can be calculated from indexes obtained from histological preparations, changes in body temperatures, and other clinical symptoms, including weight loss and efficiencies of feed utilization. Other significant errors are derived from the normal 24-hour dynamics of particular tissue constituents, which include oscillations and circadian rhythms. Experimental designs and accuracy of data are always helped by prior knowledge of 24-hour patterns of these normal fluctuations. For example, such patterns will reveal that enzyme and hormonal changes are far more dynamic than body water changes. Studies of nutrition--disease interactions are extremely complex and the researcher must be aware of and eliminate as many sources of experimental error as possible to avoid confounding the data.

Amino Acids↗

PubMed1975

Fish health--some concepts, constraints, and comparisons.

This has been an overview of fish health, a comparison of some aspects of fish husbandry with other animal husbandry, and comments concerning fish health research--especially where it is going. The 1972 disease survey identified current problems; it ranked the problems according to priority. More important, research effort has been redirected. Problems of highest priority are receiving the greatest attention; those of lesser priority are receiving the appropriately lesser attention. Just as veterinary and human medical research have become more mission-oriented, fish health research has also become much more of a problem-solving activity. There are fewer dollars; they must be used wisely and they must produce. Research in fish health is expected to yield usable information that will be of significant help in producing better fishes. If destined for the table, such fishes should convert feeds rapidly and efficiently, and they should not suffer losses from diseases. If intended for stocking, such fishes should be capable of thriving in the environment and of surviving to fulfill their destiny.

Animal Husbandry↗