Administration of dietary prebiotics improves growth performance and reduces pathogen colonization in broiler chickens

Dietary prebiotics are thought to be potentially important alternatives to antibiotic growth promoters in poultry production because of their beneficial performance and health effects. The administration of dietary prebiotics has been demonstrated to improve animal health, growth performance, and microbial food safety in poultry production. In this study, we evaluated the effects of Saccharomyces- derived prebiotic refined functional carbohydrates (RFC) with yeast culture on growth performance and gastrointestinal and environmental microbiota when administered in-feed and through drinking water to broiler chickens. Broilers were administered 2 doses of prebiotic in-feed through 42 d of production and prebiotic-treated water in the final 72 h. Administration of prebiotic RFC improved ADG and decreased cecal Campylobacter counts, while the high dose also increased final BW. Additionally, significant main effects of prebiotic RFC dose were observed with the high dose improving ADG and ADFI over the finisher phase and final BW. Although the effects were not significant, the prevalence of Campylobacter in the cecum after feed withdrawal was 17% lower when broilers were administered the high prebiotic dose, and recovery of Campylobacter from litter was up to 50% lower when broilers were administered prebiotic RFC. Our results suggest that co-administration of RFC with yeast culture as a prebiotic can be used to improve growth performance and reduce human foodborne pathogens in poultry.

Design of a Semi-Powered Stance-Control Swing-Assist Transfemoral Prosthesis

This paper describes the design of a new type of knee prosthesis called a stance-control, swing-assist (SCSA) knee prosthesis. The device is motivated by the recognition that energetically-passive stance-controlled microprocessor-controlled knees (SCMPKs) offer many desirable characteristics, such as quiet operation, low weight, high-impedance stance support, and an inertially-driven swing-phase motion. Due to the latter, however, SCMPKs are also highly susceptible to swing-phase perturbations, which can increase the likelihood of falling. The SCSA prosthesis supplements the behavior of an SCMPK with a small motor that maintains the low output impedance of the SCMPK swing state, while adding a supplemental closed-loop controller around it. This paper elaborates upon the motivation for the SCSA prosthesis, describes the design of a prosthesis prototype, and provides human-subject testing data that demonstrates potential device benefits relative to an SCMPK during both non-perturbed and perturbed walking.

Research Note: Evaluation of manganese hydroxychloride in 45-wk-old white leghorn layers using yolk and shell manganese content

The objective of the current study was to evaluate increasing levels of manganese hydroxychloride (MHC) in 45-wk-old white leghorn laying hens, using yolk and shell manganese (Mn) content as a potential marker for Mn concentration. A total of 80, 45-wk-old white leghorns were assigned to 6 dietary treatments, each consisting of 14 individually caged laying hens, with the exception of the reference diet containing 10 individually caged laying hens. The experiment consisted of a reference diet that contained 70 ppm of supplemental inorganic Mn in the form of Mn oxide and 5 experimental treatments each containing 0, 15, 30, 60, and 90 ppm supplemental MHC. Experimental birds were subjected to a 21 D depletion phase in which no supplemental Mn was included in the diet; however, during this time reference fed birds were fed the control diet (70 ppm Mn). After the 21 D depletion phase, the depleted birds were fed experimental diets for a 35 D evaluation period. Yolk and shell Mn content were analyzed at the end of the depletion phase and during the experimental phase on day 5, 10, 15, 25, and 35. During the experimental phase, Mn was replenished in the yolk and shell in all experimental treatments containing supplemental Mn; however, dose and time impacted the rate of replenishment. The yolk tended to be more sensitive to variations in Mn level as increases in Mn inclusion significantly (P < 0.05) increased concentration. These data demonstrate the ability to deplete and replenish Mn, and the use of egg yolk Mn concentration as measurement for determining changes in dietary Mn. At the conclusion of the experiment at 35 D, 60 ppm of Mn hydroxychloride seemed to be adequate in replenishing Mn to the level of the reference.

Long Noncoding RNA Functionality Beyond Sequence: The Jpx Model: Commentary on "Functional Conservation of lncRNA JPX Despite Sequence and Structural Divergence" by Karner et al. (2019)

The mouse lncRNA Jpx has been shown as an essential regulator in X-chromosome inactivation (XCI). Jpx RNA activates Xist expression through its trans-acting ability to evict CTCF from Xist promoter. Karner et al. (2019) reveals the intriguing finding that human JPX and mouse Jpx are functionally conserved although they have low similarity in the primary sequence and the secondary structure. This study provides an excellent model for studying lncRNA's evolution and epigenetic function.

The Firre locus produces a trans-acting RNA molecule that functions in hematopoiesis

RNA has been classically known to play central roles in biology, including maintaining telomeres, protein synthesis, and in sex chromosome compensation. While thousands of long noncoding RNAs (lncRNAs) have been identified, attributing RNA-based roles to lncRNA loci requires assessing whether phenotype(s) could be due to DNA regulatory elements, transcription, or the lncRNA. Here, we use the conserved X chromosome lncRNA locus Firre, as a model to discriminate between DNA- and RNA-mediated effects in vivo. We demonstrate that (i) Firre mutant mice have cell-specific hematopoietic phenotypes, and (ii) upon exposure to lipopolysaccharide, mice overexpressing Firre exhibit increased levels of pro-inflammatory cytokines and impaired survival. (iii) Deletion of Firre does not result in changes in local gene expression, but rather in changes on autosomes that can be rescued by expression of transgenic Firre RNA. Together, our results provide genetic evidence that the Firre locus produces a trans-acting lncRNA that has physiological roles in hematopoiesis.

Targeting RNA with Small Molecules: Identification of Selective, RNA-Binding Small Molecules Occupying Drug-Like Chemical Space

Although the potential value of RNA as a target for new small molecule therapeutics is becoming increasingly credible, the physicochemical properties required for small molecules to selectively bind to RNA remain relatively unexplored. To investigate the druggability of RNAs with small molecules, we have employed affinity mass spectrometry, using the Automated Ligand Identification System (ALIS), to screen 42 RNAs from a variety of RNA classes, each against an array of chemically diverse drug-like small molecules (~50,000 compounds) and functionally annotated tool compounds (~5100 compounds). The set of RNA–small molecule interactions that was generated was compared with that for protein–small molecule interactions, and naïve Bayesian models were constructed to determine the types of specific chemical properties that bias small molecules toward binding to RNA. This set of RNA-selective chemical features was then used to build an RNA-focused set of ~3800 small molecules that demonstrated increased propensity toward binding the RNA target set. In addition, the data provide an overview of the specific physicochemical properties that help to enable binding to potential RNA targets. This work has increased the understanding of the chemical properties that are involved in small molecule binding to RNA, and the methodology used here is generally applicable to RNA-focused drug discovery efforts.

Patients with more comorbidities have better detection but poorer management of chronic diseases

Background

The burden of non-communicable diseases (NCDs) is rising rapidly in middle-income countries (MICs), where NCDs are often undiagnosed, untreated and uncontrolled. How comorbidity impacts diagnosis, treatment, and control of NCDs is an emerging area of research inquiry and have significant clinical implications as highlighted in the recent National Institute for Care Excellence (NICE) guidelines for treating patients suffering from multiple NCDs. This is the first study to examine the association between increasing numbers of comorbidities with being undiagnosed, intreated, and uncontrolled for NCDs, in six large MICs.

Methods

Cross-sectional analysis of WHO SAGE Wave 1 (2007-10), which consisted of adults aged ≥18 years from six populous MICs including, China, Ghana, India, Mexico, Russia and South Africa (overall n = 41, 557).

Results

Higher number of comorbidities was associated with better detection of hypertension, angina and arthritis, and better odds of having treatment for hypertension and angina. However, increasing comorbidity had the opposite effect on being uncontrolled, and was associated with increased odds of uncontrolled hypertension, angina, arthritis, and asthma. Comorbidity with concordant conditions was associated with improved diagnosis and treatment of hypertension and angina. Comorbidity with concordant conditions was not associated with decreased nor increased odds of being uncontrolled for all NCDs.

Conclusions

Patients with more comorbidities have better diagnosis of chronic conditions, but this does not translate into better management and control of these conditions. Improving continuity of care and monitoring treatment are priorities for health systems with ageing populations.

Key messages

Patients with more comorbidities have better diagnosis of chronic conditions. but this does not translate into better management and control of these conditions.

Role of the Chromosome Architectural Factor SMCHD1 in X-Chromosome Inactivation, Gene Regulation, and Disease in Humans

Structural maintenance of chromosomes flexible hinge domain-containing 1 (SMCHD1) is an architectural factor critical for X-chromosome inactivation (XCI) and the repression of select autosomal gene clusters. In mice, homozygous nonsense mutations in Smchd1 cause female-specific embryonic lethality due to an XCI defect. However, although human mutations in SMCHD1 are associated with congenital arhinia and facioscapulohumeral muscular dystrophy type 2 (FSHD2), the diseases do not show a sex-specific bias, despite the essential nature of XCI in humans. To investigate whether there is a dosage imbalance for the sex chromosomes, we here analyze transcriptomic data from arhinia and FSHD2 patient blood and muscle cells. We find that X-linked dosage compensation is maintained in these patients. In mice, SMCHD1 controls not only protocadherin (Pcdh) gene clusters, but also Hox genes critical for craniofacial development. Ablating Smchd1 results in aberrant expression of these genes, coinciding with altered chromatin states and three-dimensional (3D) topological organization. In a subset of FSHD2 and arhinia patients, we also found dysregulation of clustered PCDH, but not HOX genes. Overall, our study demonstrates preservation of XCI in arhinia and FSHD2, and implicates SMCHD1 in the regulation of the 3D organization of select autosomal gene clusters.

Denaturing CLIP, dCLIP, Pipeline Identifies Discrete RNA Footprints on Chromatin-Associated Proteins and Reveals that CBX7 Targets 3' UTRs to Regulate mRNA Expression

Interaction networks between chromatin complexes and long noncoding RNAs have become a recurrent theme in epigenetic regulation. However, technical limitations have precluded identification of RNA binding motifs for chromatin-associated proteins. Here, we add a denaturation step to UV-crosslink RNA immunoprecipitation (dCLIP) and apply dCLIP to mouse and human chromobox homolog 7 (CBX7), an RNA binding subunit of Polycomb repressive complex 1 (PRC1). In both species, CBX7 predominantly binds 3' UTRs of messenger RNAs. CBX7 binds with a median RNA "footprint" of 171-183 nucleotides, the small size of which facilitates motif identification by bioinformatics. We find four families of consensus RNA motifs in mouse, and independent analysis of human CBX7 dCLIP data identifies similar motifs. Their mutation abolishes CBX7 binding in vitro. Pharmacological intervention with antisense oligonucleotides paradoxically increases CBX7 binding and enhances gene expression. These data support the utility of dCLIP and reveal an unexpected functional interaction between CBX7 and the 3' UTRs of mRNA.

PRC1 collaborates with SMCHD1 to fold the X-chromosome and spread Xist RNA between chromosome compartments

X-chromosome inactivation triggers fusion of A/B compartments to inactive X (Xi)-specific structures known as S1 and S2 compartments. SMCHD1 then merges S1/S2s to form the Xi super-structure. Here, we ask how S1/S2 compartments form and reveal that Xist RNA drives their formation via recruitment of Polycomb repressive complex 1 (PRC1). Ablating Smchd1 in post-XCI cells unveils S1/S2 structures. Loss of SMCHD1 leads to trapping Xist in the S1 compartment, impairing RNA spreading into S2. On the other hand, depleting Xist, PRC1, or HNRNPK precludes re-emergence of S1/S2 structures, and loss of S1/S2 compartments paradoxically strengthens the partition between Xi megadomains. Finally, Xi-reactivation in post-XCI cells can be enhanced by depleting both SMCHD1 and DNA methylation. We conclude that Xist, PRC1, and SMCHD1 collaborate in an obligatory, sequential manner to partition, fuse, and direct self-association of Xi compartments required for proper spreading of Xist RNA.

The inactive X (Xi)-specific S1/S2 chromosome compartments are merged by SMCHD1, but how the S1/S2 structure is constructed is unclear. The authors find that PRC1 drives the formation of S1/S2s and that the stepwise folding process of the Xi facilitates Xist RNA spreading between Xi compartments.

En bloc and segmental deletions of human XIST reveal X chromosome inactivation-involving RNA elements

The XIST RNA is a non-coding RNA that induces X chromosome inactivation (XCI). Unlike the mouse Xist RNA, how the human XIST RNA controls XCI in female cells is less well characterized, and its functional motifs remain unclear. To systematically decipher the XCI-involving elements of XIST RNA, 11 smaller XIST segments, including repeats A, D and E; human-specific repeat elements; the promoter; and non-repetitive exons, as well as the entire XIST gene, were homozygously deleted in K562 cells using the Cas9 nuclease and paired guide RNAs at high efficiencies, followed by high-throughput RNA sequencing and RNA fluorescence in situ hybridization experiments. Clones containing en bloc and promoter deletions that consistently displayed no XIST RNAs and a global up-regulation of X-linked genes confirmed that the deletion of XIST reactivates the inactive X chromosome. Systematic analyses of segmental deletions delineated that exon 5 harboring the non-repeat element is important for X-inactivation maintenance, whereas exons 2, 3 and 4 as well as the other repeats in exon 1 are less important, a different situation from that of mouse Xist. This Cas9-assisted dissection of XIST allowed us to understand the unique functional domains within the human XIST RNA.

Xist Deletional Analysis Reveals an Interdependency between Xist RNA and Polycomb Complexes for Spreading along the Inactive X

During X-inactivation, Xist RNA spreads along an entire chromosome to establish silencing. However, the mechanism and functional RNA elements involved in spreading remain undefined. By performing a comprehensive endogenous Xist deletion screen, we identify Repeat B as crucial for spreading Xist and maintaining Polycomb repressive complexes 1 and 2 (PRC1/PRC2) along the inactive X (Xi). Unexpectedly, spreading of these three factors is inextricably linked. Deleting Repeat B or its direct binding partner, HNRNPK, compromises recruitment of PRC1 and PRC2. In turn, ablating PRC1 or PRC2 impairs Xist spreading. Therefore, Xist and Polycomb complexes require each other to propagate along the Xi, suggesting a positive feedback mechanism between RNA initiator and protein effectors. Perturbing Xist/Polycomb spreading causes failure of de novo Xi silencing, with partial compensatory downregulation of the active X, and also disrupts topological Xi reconfiguration. Thus, Repeat B is a multifunctional element that integrates interdependent Xist/Polycomb spreading, silencing, and changes in chromosome architecture.

Exploration of CTCF post-translation modifications uncovers Serine-224 phosphorylation by PLK1 at pericentric regions during the G2/M transition

The zinc finger CCCTC-binding protein (CTCF) carries out many functions in the cell. Although previous studies sought to explain CTCF multivalency based on sequence composition of binding sites, few examined how CTCF post-translational modification (PTM) could contribute to function. Here, we performed CTCF mass spectrometry, identified a novel phosphorylation site at Serine 224 (Ser224-P), and demonstrate that phosphorylation is carried out by Polo-like kinase 1 (PLK1). CTCF Ser224-P is chromatin-associated, mapping to at least a subset of known CTCF sites. CTCF Ser224-P accumulates during the G2/M transition of the cell cycle and is enriched at pericentric regions. The phospho-obviation mutant, S224A, appeared normal. However, the phospho-mimic mutant, S224E, is detrimental to mouse embryonic stem cell colonies. While ploidy and chromatin architecture appear unaffected, S224E mutants differentially express hundreds of genes, including p53 and p21. We have thus identified a new CTCF PTM and provided evidence of biological function.

Xist RNA antagonizes the SWI/SNF chromatin remodeler BRG1 on the inactive X chromosome

The noncoding RNA Xist recruits silencing factors to the inactive X chromosome (Xi) and facilitates re-organization of Xi structure. Here, we examine the mouse epigenomic landscape of Xi and assess how Xist alters chromatin accessibility. Interestingly, Xist deletion triggers a gain of accessibility of selective chromatin regions that is regulated by BRG1, an ATPase subunit of the SWI/SNF chromatin remodeling complex. In vitro, RNA binding inhibits nucleosome remodeling and ATPase activities of BRG1, while in cell culture Xist directly interacts with BRG1 and expels BRG1 from the Xi. Xist ablation leads to a selective return of BRG1 in cis, starting from pre-existing BRG1 sites that are free of Xist. BRG1 re-association correlates with cohesin binding and restoration of topologically associated domains (TADs), and results in formation of de novo Xi “superloops.” Thus, Xist binding inhibits BRG1’s nucleosome remodeling activity and results in expulsion of the SWI/SNF complex from the Xi.

Multiple Histone Methyl-Lysine Readers Ensure Robust Development and Germline Immortality in Caenorhabditis elegans

Chromatin modifications, including methylation of histone H3 at lysine 27 (H3K27me) by the Polycomb group proteins, play a broadly conserved role in the maintenance of cell fate. Diverse chromatin organization modifier (chromo) domain proteins act as "readers" of histone methylation states. However, understanding the functional relationships among chromo domains and their roles in the inheritance of gene expression patterns remains challenging. Here, we identify two chromo-domain proteins, CEC-1 and CEC-6, as potential readers of H3K27me in Caenorhabditis elegans, where they have divergent expression patterns and contribute to distinct phenotypes. Both cec-1 and cec-6 genetically interact with another chromo-domain gene, cec-3, a reader of H3K9 methylation. Combined loss of cec-1 and cec-3 leads to developmental defects in the adult that result in decreased fitness. Furthermore, loss of cec-6 and cec-3 surprisingly leads to a progressive loss of fertility across generations, a "mortal germline" phenotype. Our results provide evidence of functional compensation between H3K27me and H3K9me heterochromatin pathways, and show that histone methylation readers contribute to both somatic development and transgenerational fitness.

Evaluation of different dietary alterations in their ability to mitigate the incidence and severity of woody breast and white striping in commercial male broilers

The following study was conducted to define how multiple nutritional strategies affect broiler performance, meat yield, and the presence and severity of white striping (WS) and woody breast (WB) in high-yielding broilers. Relative to a commercial set of reference broiler diets (Commercial reference diet; Trt 1) that were fed in a 4-phase program, the following nutritional strategies were investigated: increasing the ratio of digestible arginine: digestible lysine (dArg: dLys ranged from 113 to 126; Trt 2), supplementing Trt 1 with 94.4 mg vitamin C/kg feed (Trt 3), doubling the vitamin pack inclusion rate (Trt 4), reducing the digestible amino acid density (dAA) of only the grower phase by 15% and feeding the same Trt 1 starter, finisher, and withdraw diets (Trt 5), and combining the 4 strategies just mentioned (Trt 6). There was no difference in performance at the end of the starter phase (P = 0.066); however, at the end of the grower and finisher phases, feeding lower dAA grower diets suppressed BW (Trts 5 and 6; P < 0.001) and increased FCR. Differences in performance amongst all treatments disappeared at day 49 (P = 0.220). No differences were observed in average breast weight (P = 0.188); however, breast yield (as a % of live weight) was greatest for Trt 1 and least for Trt 6 (P = 0.041). The WB score dropped from 1.83 in Trt 1 to 1.49, 1.27, 1.74, 1.53, and 1.43 in treatments 2 to 6, respectively (P = 0.018). These changes were the result of a shift in WB score, where the WB class that contained scores of 2 and 3 shifted from 61.3% in Trt 1 to 49.3, 35.9, 60.0, 50.8, and 38.7 in treatments 2 to 6, respectively. Given the FCR, breast weight data and the fact that high WB scores result in a devaluation of breast meat, feeding a higher ratio of dArg: dLys, higher vitamin C, or lower dAA in the grower phase results in better breast meat quality and value.

Impact of a multicarbohydrase containing α-galactosidase and xylanase on ileal digestible energy, crude protein digestibility, and ileal amino acid digestibility in broiler chickens

Exogenous enzymatic supplementation of poultry feeds, including α-galactosidase and xylanase, has been shown to increase metabolically available energy, although little information has been published on the impact on amino acid digestibility. An experiment was conducted to investigate a multicarbohydrase containing α-galactosidase and xylanase on amino acid digestibility, ileal digestible energy (IDE), and CP in male broiler chicks. The experiment was a 2 × 2 (diet × enzyme) factorial arrangement with 15 replicates of 8 male broilers per replicate raised for 21 d in a battery setting. The 2 dietary treatments included a positive control (PC) and a negative control (NC) diet formulated to contain 2.5% less calculated AME and digestible amino acids. Each of these diets was fed with and without enzyme. Broilers were fed a starter diet from 0-14 d (crumble) and a grower from 14-21 d (pellet). Birds were sampled on day 21 to determine ileal amino acid digestibility, IDE, and CP digestibility. Titanium dioxide (TiO2) was used as an indigestible marker for the determination of digestibility coefficients. Total ileal amino acid digestibility was increased (P = 0.008) by 3.80% with the inclusion of enzyme. Methionine and lysine digestibility was improved (P < 0.05) with the inclusion of enzyme by 3.37% and 2.61%, respectively. Enzyme inclusion increased (P = 0.001) cysteine digestibility by 9.3%. Diet-influenced ileal amino acid digestibility with tryptophan, threonine, isoleucine, and valine digestibility being increased (P < 0.05) in the PC when compared to the NC. IDE was decreased (P = 0.037) in broilers fed the NC diet by 100 kcal/kg feed when compared to broilers fed the PC diet. Enzyme inclusion increased (P = 0.047) IDE value by 90 kcal/kg. Crude protein digestibility was not influenced by diet; however, similar improvements in CP digestibility with enzyme inclusion were observed as with energy. These data support the benefits of a multicarbohydrase containing α-galactosidase and xylanase inclusion to improve nutrient and ileal amino acid digestibility across multiple dietary nutrient profiles.

Correction to: Measuring and understanding adherence in a home-based exercise intervention during chemotherapy for early breast cancer

In the original publication, the sixth author name was published incorrectly as A. Wood. The correct author name should read as W. A. Wood.

Loss of H3K27me3 Imprinting in Somatic Cell Nuclear Transfer Embryos Disrupts Post-Implantation Development

Animal cloning can be achieved through somatic cell nuclear transfer (SCNT), although the live birth rate is relatively low. Recent studies have identified H3K9me3 in donor cells and abnormal Xist activation as epigenetic barriers that impede SCNT. Here we overcome these barriers using a combination of Xist knockout donor cells and overexpression of Kdm4 to achieve more than 20% efficiency of mouse SCNT. However, post-implantation defects and abnormal placentas were still observed, indicating that additional epigenetic barriers impede SCNT cloning. Comparative DNA methylome analysis of IVF and SCNT blastocysts identified abnormally methylated regions in SCNT embryos despite successful global reprogramming of the methylome. Strikingly, allelic transcriptomic and ChIP-seq analyses of pre-implantation SCNT embryos revealed complete loss of H3K27me3 imprinting, which may account for the postnatal developmental defects observed in SCNT embryos. Together, these results provide an efficient method for mouse cloning while paving the way for further improving SCNT efficiency.

Efficacy of β-mannanase on broiler growth performance and energy utilization in the presence of increasing dietary galactomannan

An experiment was conducted to investigate the impact of β-mannanase inclusion on growth performance, viscosity, and energy utilization in broilers fed diets varying in galactomannan (GM) concentrations. Treatments were arranged as a 3 (GM concentration) × 3 (β-mannanase inclusion) factorial randomized complete block design with 12 replicates of 29 male broilers per replicate for a 42-d experiment. Efforts were made to reduce the amount of soybean meal, and thus GM, in the basal diet with guar gum included at 0, 0.21, or 0.42% to achieve a GM supplementation of 1,500 and 3,000 ppm, respectively. Beta-mannanase was included at 0, 200, or 400 g/ton. Broilers were fed a starter (d 0 to 14), grower (d 15 to 28), and finisher diets (d 29 to 42). Growth performance was monitored and ileal contents collected on d 14, 28, and 42 to determine ileal digestible energy (IDE) and intestinal viscosity. Increasing levels of GM negatively (P < 0.05) influenced body weight (BW) following the starter and grower periods and increased (P < 0.01) mortality corrected feed conversion ratio (FCR) throughout the study. Reduced growth performance was associated with increased (P < 0.05) intestinal viscosity and decreased (P < 0.05) IDE when GM inclusion was increased. Inclusion of β-mannanase in diets containing supplemental GM on d 28, increased average BW to levels similar to diets without supplemental GM. Improvements in FCR were also observed with β-mannanase inclusion in diets containing supplemental GM. Ileal digestible energy was increased (P < 0.05) with the addition of β-mannanase on d 28 of age. Multiple interactions in growth performance, intestinal viscosity, and IDE were associated with β-mannanase administration. In conclusion, β-mannanase improved IDE, reduced intestinal viscosity, and improved growth performance; however, the observed benefit was dependent upon dietary GM concentration.

Effects of direct-fed microorganisms and enzyme blend co-administration on intestinal bacteria in broilers fed diets with or without antibiotics

Direct-fed microorganisms (DFM) and exogenous enzymes have been demonstrated to improve growth performance in poultry and are potentially important alternatives to antibiotic growth promoters (AGP). We investigated the administration of a feed additive composed of a DFM product containing spores of 3 Bacillus amyloliquefaciens strains and an enzyme blend of endo-xylanase, α-amylase, and serine-protease in diets with or without sub-therapeutic antibiotics in broiler chickens over a 42-d growth period. Evaluation of growth performance determined feed efficiency of broiler chickens which were administered the feed additive was comparable to those fed a diet containing AGPs. Characterization of the gastrointestinal microbiota using culture-dependent methods determined administration of the feed additive increased counts of total Lactic Acid Bacteria (LAB) relative to a negative control and reduced Clostridium perfringens to levels similar to antibiotic administration. Additionally, greater counts of total LAB were observed to be significantly associated with reduced feed conversion ratio, whereas greater counts of C. perfringens were observed to be significantly associated with increased feed conversion ratio. Our results suggest the co-administration of DFMs and exogenous enzymes may be an important component of antibiotic free poultry production programs and LAB and C. perfringens may be important targets in the development of alternatives to AGPs in poultry production.

Changes in immune and metabolic gut response in broilers fed β-mannanase in β-mannan-containing diets

β-galactomannans found in soy-based broiler feed are known to cause physiological effects that are hypothesized to be related to gut inflammation. Previous studies have shown that the incorporation of β-mannanase in the diet or as a supplement results in improvements to certain performance parameters related to gut health and feed conversion. Using kinome analysis, we characterized the mechanism of β-galactomannan activity and supplementation with β-mannanase on the gut of commercial broilers to understand the mode of action. Two doses of β-mannanase (200 and 400 g/ton of feed) with and without inclusion of additional β-galactomannan (3,000 ppm) were tested at 3 time points (d 14, d 28, and d 42 post hatch). Broilers were fed starter (d 0 to 14), grower (d 15 to 28), and finisher diets (d 29 to 42). Jejuna were collected from birds from each treatment condition and time point. Cluster analysis of the kinome data showed that birds clustered first by age, then predominantly by whether β-mannanase had been included in the diet. Biological pathway analysis showed that the inclusion of additional β-galactomannan into the diet resulted in increased signaling related to immune response, relative to our normal control diet (with reduced soybean meal). The addition of β-mannanase to the enhanced β-galactomannan diet eliminated the majority of this immune-related signaling, indicating that the feed-induced immune response within the jejuna had been eliminated by the addition of β-mannanase. We also saw changes in specific metabolic and gut function pathways in birds fed β-mannanase. These observed changes in β-mannanase-fed birds are likely the mechanism for the enhanced performance and feed conversion observed in birds given β-mannanase in their diets.

Measuring and understanding adherence in a home-based exercise intervention during chemotherapy for early breast cancer

PURPOSE

Ensuring and measuring adherence to prescribed exercise regimens are fundamental challenges in intervention studies to promote exercise in adults with cancer. This study reports exercise adherence in women who were asked to walk 150 min/week throughout chemotherapy treatment for early breast cancer. Participants were asked to wear a Fitbit^TM throughout their waking hours, and Fitbit steps were uploaded directly into study computers.

METHODS

Descriptive statistics are reported, and both unadjusted and multivariable linear regression models were used to assess associations between participant characteristics, breast cancer diagnosis, treatment, chemotherapy toxicities, and patient-reported symptoms with average Fitbit steps/week.

RESULTS

Of 127 women consented to the study, 100 had analyzable Fitbit data (79%); mean age was 48 and 31% were non-white. Mean walking steps were 3956 per day. Nineteen percent were fully adherent with the target of 6686 steps/day and an additional 24% were moderately adherent. In unadjusted analysis, baseline variables associated with fewer Fitbit steps were: non-white race (p = 0.012), high school education or less (p = 0.0005), higher body mass index (p = 0.0024), and never/almost never drinking alcohol (p = 0.0048). Physical activity variables associated with greater Fitbit steps were: pre-chemotherapy history of vigorous physical activity (p = 0.0091) and higher self-reported walking minutes/week (p < 0.001), and higher outcome expectations from exercise (p = 0.014). Higher baseline anxiety (p = 0.03) and higher number of chemotherapy-related symptoms rates "severe/very severe" (p = 0.012) were associated with fewer steps. In multivariable analysis, white race was associated with 12,146 greater Fitbit steps per week (p = 0.004), as was self-reported walking minutes prior to start of chemotherapy (p < 0.0001).

CONCLUSIONS

Inexpensive commercial-grade activity trackers, with data uploaded directly into research computers, enable objective monitoring of home-based exercise interventions in adults diagnosed with cancer. Analysis of the association of walking steps with participant characteristics at baseline and toxicities during chemotherapy can identify reasons for low/non-adherence with prescribed exercise regimens.