The relative age effect (RAE) has been the focus of numerous studies; however, there are still fewer studies in women's sports than in men's sports. In this study, all female players (N = 2,255) who ...participated in Chinese junior tennis competitions (U12, U14, U16, and the National Junior Team) from 2014 to 2019 were investigated in terms of competitors' birth dates and year-end rankings. For the purposes of the analysis, the birth dates were also separated into quarters and half years. The study's objectives were to analyze the prevalence of the RAE among young Chinese female tennis players and to further examine how the RAE affects athletic performance. Differences between the observed and expected distributions of birth dates were tested using the chi-square statistic, and subsequent calculations were tested using odds ratios. The RAE was discovered to be present in every group of Chinese junior female tennis players (p < 0.001), with the proportions of those born in the first half of the year being 56.4% (U12), 53.1% (U14), and 57.0% (U16), respectively. The RAE for athletes selected for the National Women's Junior Tennis Team was even more significant, with the percentage of birth dates in the first half of the year at 61.2%. Finally, we observed a tendency for the effect of the RAE on the athletic performance of adolescent female tennis players to diminish with age.
The aim of this study was to evaluate a combination diet of organic acids and essential oils on epithelial restitution, intestinal microflora, and volatile fatty acids in broiler chickens. A total of ...144 1-day-old male chicks (Cobb 500) were allotted to 3 treatment groups consisting of 6 replicates with 8 birds per replicate. The dietary treatments were as follows: control group (CON, basal diet), antibiotics group (ANT, control + 0.15 g/kg enramycin), and addition group (EOA, control + 0.30 g/kg encapsulated organic acids and essential oils). Compared to the CON group, the EOA group showed a higher feed conversion ratio (FCR) (P < 0.05) at day 42. The ANT group showed the lowest count of Lactobacillus spp. (P < 0.05) and the highest count of Escherichia coli (P < 0.05) in the ileal digesta. Birds that were fed the EOA-supplemented diet had decreased populations of E. coli (P < 0.05). Compared with the ANT group, supplementation with EOA tended to reduce the pH of jejunal digesta (P = 0.079) and ileal digesta (P = 0.078) but significantly increased the concentration of butyric acid (P < 0.05) and tended to increase the concentrations of acetic acid (P = 0.087) and total short-chain fatty acids (SCFA; P = 0.098) in the ileal digesta. The EOA group showed higher sucrase and maltase activities of jejunal mucosa (P < 0.05) than those in the other groups. The EOA supplementation increased (P < 0.05) claudin-1 mRNA expression in the jejunum. Compared with the other groups, enramycin supplementation significantly reduced jejunal mucosa sIgA (P < 0.05) and down-regulated Mucin-2 and TLR2 mRNA relative expression (P < 0.05) in the jejunal mucosa of broiler chickens. Both EOA and enramycin contribute beneficially to FCR because of their antimicrobial action. EOA may reduce harmful bacteria and promote digestive enzyme activity and higher concentrations of SCFA. In contrast, enramycin may inhibit the growth of beneficial bacteria and reduce the need for intestinal mucosal barrier function.
The aim of the experiment was to study the effects of feeding blends of sorbic acid, fumaric acid, and thymol (EOA) on growth performance, digestive functions, and immunity of broiler chickens. A ...total of 640 one-day-old male Cobb 500 chicks with similar BW (41.8 ± 0.6 g) were randomly divided into 4 dietary treatment groups consisting of 10 replicates with 16 birds per replicate and fed a basal diet until d 42 (CON) or diets with 0.15 g/kg enramycin during the grower period (AG), 0.30 g/kg EOA during the grower period (EG), or 0.30 g/kg EOA during the finisher period (EF). At d 42, the feed conversion ratio was reduced (P < 0.05) for birds in EG group compared with other groups. Birds in EG group showed a higher villus height of the duodenum and jejunum and muscular layers of the duodenum and ileum than birds in CON group (P < 0.05). Compared with other groups, crypt depth of the jejunum and ileum was markedly increased (P < 0.05) by EOA supplementation during the finisher period at d 42. The EOA supplementation during grower period increased significantly lipase, trypsin and chymotrypsin activities of the duodenum at d 21 and 42, as well as lipase and trypsin at d 21, and trypsin and chymotrypsin at d 42 in the jejunum, and trypsin and chymotrypsin activities of the ileum at d 21 compared to the control diet (P < 0.05). Birds of EG and EF groups showed a higher (P < 0.05) spleen index than birds of CON group. The level of secretory immunoglobulin A in duodenal and ileal mucosa was increased (P < 0.05) in EF group at d 42 compared with other groups. In conclusion, the results indicate that EOA can be effectively applied in broiler diets, especially during the grower phase by improving intestinal morphology and increasing digestive enzyme activity.
It is well-known that essential oil thymol exhibits antibacterial activity. The protective effects of thymol on pig intestine during inflammation is yet to be investigated. In this study, an in vitro ...lipopolysaccharide (LPS)-induced inflammation model using IPEC-J2 cells was established. Cells were pretreated with thymol for 1 h and then exposed to LPS for various assays. Interleukin 8 (IL-8) secretion, the mRNA abundance of cytokines, reactive oxygen species (ROS), nutrient transporters, and tight junction proteins was measured. The results showed that LPS stimulation increased IL-8 secretion, ROS production, and tumor necrosis factor alpha (TNF-α) mRNA abundance (P < 0.05), but the mRNA abundance of sodium-dependent glucose transporter 1 (SGLT1), excitatory amino acid transporter 1 (EAAC1), and H+/peptide cotransporter 1 (PepT1) were decreased (P < 0.05). Thymol blocked ROS production (P < 0.05) and tended to decrease the production of LPS-induced IL-8 secretion (P = 0.0766). The mRNA abundance of IL-8 and TNF-α was reduced by thymol pretreatment (P < 0.05), but thymol did not improve the gene expression of nutrient transporters (P > 0.05). The transepithelial electrical resistance (TEER) was reduced and cell permeability increased by LPS treatment (P < 0.05), but these effects were attenuated by thymol (P < 0.05). Moreover, thymol increased zonula occludens-1 (ZO-1) and actin staining in the cells. However, the mRNA abundance of ZO-1 and occludin-3 was not affected by either LPS or thymol treatments. These results indicated that thymol enhances barrier function and reduce ROS production and pro-inflammatory cytokine gene expression in the epithelial cells during inflammation. The regulation of barrier function by thymol and LPS may be at post-transcriptional or post-translational levels.
This review article summarizes the efficacy, feasibility and potential mechanisms of the application of essential oils as antibiotic alternatives in swine production. Although there are numerous ...studies demonstrating that essential oils have several properties, such as antimicrobial, antioxidative and anti-inflammatory effects, feed palatability enhancement and improvement in gut growth and health, there is still a need of further investigations to elucidate the mechanisms underlying their functions. In the past, the results has been inconsistent in both laboratory and field studies because of the varied product compositions, dosages, purities and growing stages and conditions of animals. The minimal inhibitory concentration (MIC) of essential oils needed for killing enteric pathogens may not ensure the optimal feed intake and the essential oils inclusion cost may be too high in swine production. With the lipophilic and volatile nature of essential oils, there is a challenge in effective delivery of essential oils within pig gut and this challenge can partially be resolved by microencapsulation and nanotechnology. The effects of essential oils on inflammation, oxidative stress, microbiome, gut chemosensing and bacterial quorum sensing (QS) have led to better production performance of animals fed essential oils in a number of studies. It has been demonstrated that essential oils have good potential as antibiotic alternatives in feeds for swine production. The combination of different essential oils and other compounds (synergistic effect) such as organic acids seems to be a promising approach to improve the efficacy and safety of essential oils in applications. High-throughput systems technologies have been developed recently, which will allow us to dissect the mechanisms underlying the functions of essential oils and facilitate the use of essential oils in swine production.
The gut microbiota has long been of research interest due to its importance to human health, nutrition, and well-being. A healthy gut microbiota (properly balanced bacterial groups) is normally ...required for human health by maintaining host immune homeostasis, nutrient intake, as well as gut development. An unbalanced gut microbiota is often associated with the pathogenesis of both acute and chronic diseases, such as infectious diarrhea, inflammatory bowel diseases, obesity, diabetes, colon cancer, and neonatal necrotizing enterocolitis. It has been clearly demonstrated that the gut microbiota can be modulated by many factors including diet. Dietary fiber can benefit human health through different mechanisms, including physical effect, immunomodulation, colonic fermentation, and prebiotic effect. In the past, determination of microbiota changes and corresponding functions in response to dietary treatments has been a challenge, largely due to the limitation of conventional microbiological technology. With the completion of human and other genome projects as well as the ongoing human microbiome project, revolutionary technologies characterized by culture-independent, high throughput, high efficiency and rapid computation are becoming available for studying gut microbiota. These advanced tools include quantitative polymerase chain reaction (Q-PCR) analysis, PCR-based DNA profiling techniques, DNA microarray, flow cytometry, insertion sequencing, and particularly next generation DNA sequencing and bioinformatics analyses. These robust, powerful methods have enabled more comprehensive studies on the gut microbiota and its functions including its interaction with host and diet. Moreover, integrative use of gnotobiotic and knock-out/transgenic animals and functional genomics approaches would further improve our understanding of the gut microbiome. The advances in microbiota research would particularly enhance our ability to study dietary fiber and its benefits to human health and nutrition. New knowledge on the modulation of gut microbiota by dietary fiber is critical for the development of effective strategies to improve human health and to treat microbiota associated-diseases.
As we advance in the search for antibiotic-alternatives, harnessing plant materials with high total polyphenol concentration (TPC) would be quintessential. Given the high TPC in red osier dogwood ...(ROD) extract, the current study aimed to determine its efficacy on the growth performance, intestinal health, blood biochemistry, and antioxidant capacity of broiler chickens. A 21-day 4x2 factorial feeding trial was conducted based on two main factors namely, dietary treatments and Salmonella Enteritidis Lipopolysaccharides SE-LPS) challenge. A total of 384 one-day-old mixed-sex Cobb-500 broiler chicks were randomly allotted to four dietary treatments - Negative control (NC), NC + 0.05% bacitracin methylene disalicylate (BMD), NC + 0.3%ROD, and NC+0.5% ROD. Each treatment was assigned to eight replicates with six birds/replicate. On d 13 and 20, half of the birds were intraperitoneally injected with 1mL phosphate-buffered-saline /kg BW of birds (Unchallenged-group) and the remaining half with 1mg SE-LPS /kg BW of birds (Challenged-group). Average weight gain (AWG), average feed intake (AFI), feed conversion ratio (FCR), and mortality were determined weekly. On d 21, ten chickens/treatment were euthanized for measuring blood biochemical parameters, immune organ weights, caecal SCFA, and caeca microbiota. The SE-LPS decreased (P < 0.05) AWG and FCR on d 14 and 21, respectively. On d 14, 21, and overall basis, both ROD extract levels marginally improved (P < 0.05) the AWG of unchallenged birds compared to other treatments in the unchallenged-group. Challenged and unchallenged birds fed ROD extract had deeper (P < 0.05) crypt depth (CD) and higher villus height:CD, respectively, in the ileum. Globulin (GLB) and albumin:GLB were increased and reduced (P < 0.05), respectively, among birds fed 0.3%ROD compared to other treatments. There was no treatment effect on caeca SCFA, relative weight of immune organs, and serum antioxidants. Birds fed ROD extract had a higher (P < 0.05) relative abundance of caecal Lactobacillus and Streptococcus genera compared to the antibiotic treatment. Conclusively, incorporating 0.3% and 0.5%ROD extract into broiler chickens' nutrition improved growth performance and ileal morphology, and modified caecal microbiota of broiler chickens, regardless of the intraperitoneal SE-LPS challenge.
This study investigated the effects of encapsulated cinnamaldehyde (CIN) and citral (CIT) alone or in combination (CIN + CIT) on the growth performance and cecal microbiota of nonvaccinated broilers ...and broilers vaccinated against coccidiosis. Vaccinated (1,600) and nonvaccinated (1,600) 0-day-old male Cobb500 broilers were randomly allocated to 5 treatments: basal diet (control) and basal diet supplemented with bacitracin (BAC, 55 ppm), CIN (100 ppm), CIT (100 ppm), and CIN (100 ppm) + CIT (100 ppm). In general, body weight (BW) and feed conversion ratio were significantly improved in birds treated with BAC, CIN, CIT, and CIN + CIT (P < 0.05) but were all decreased in vaccinated birds compared with nonvaccinated birds (P < 0.05). Significant interactions (P < 0.05) between vaccination and treatments for average daily gain during the periods of starter (day 0–9) and BW on day 10 were noted. Broilers receiving vaccines (P < 0.01) or feed supplemented with BAC, CIN, CIT, or CIN + CIT (P < 0.01) showed reductions in mortality rate from day 0 to 28. The incidences of minor coccidiosis were higher (P < 0.05) in vaccinated birds than in nonvaccinated birds. Diet supplementation with BAC or tested encapsulated essential oils showed comparable effects on the coccidiosis incidences. Similar to BAC, CIN and its combination with CIT reduced both incidence and severity of necrotic enteritis (P < 0.05). No treatment effects were observed on the cecal microbiota at the phyla level. At the genus level, significant differences between vaccination and treatment groups were observed for 5 (Lactobacillus, Ruminococcus, Faecalibacterium, Enterococcus, and Clostridium) of 40 detected genera (P < 0.05). The genus Lactobacillus was more abundant in broilers fed with CIT, while Clostridium and Enterococcus were less abundant in broilers fed with CIN, CIT, or CIN + CIT in both the vaccinated and nonvaccinated groups. Results from this study suggested that CIN alone or in combination with CIT in feed could improve chicken growth performance to the level comparable with BAC and alter cecal microbiota composition.
Butyrate can modulate the immune response and energy expenditure of animals and enhance intestinal health. The present study investigated changes in the intestinal microbiota composition and serum ...metabolites of young broilers in response to 3,000 ppm butyrate in the form of butyrate glycerides (BG) via pyrosequencing of bacterial 16S rRNA genes and nuclear magnetic resonance (NMR). The dietary treatment did not affect the alpha diversity of intestinal microbiota, but altered its composition. Thirty-nine key operational taxonomic units (OTUs) in differentiating cecal microbiota community structures between BG treated and untreated chickens were also identified. Bifidobacterium was, in particular, affected by the dietary treatment significantly, showing an increase in not only the abundance (approximately 3 fold, P ≤ 0.05) but also the species diversity. The (NMR)-based analysis revealed an increase in serum concentrations of alanine, low-density and very low-density lipoproteins, and lipids (P ≤ 0.05) by BG. More interestingly, the dietary treatment also boosted (P ≤ 0.05) serum concentrations of bacterial metabolites, including choline, glycerophosphorylcholine, dimethylamine, trimethylamine, trimethylamine-N-oxide, lactate, and succinate. In conclusion, the data suggest the modulation of intestinal microbiota and serum metabolites by BG dietary treatment and potential contribution of intestinal bacteria to lipid metabolism/energy homeostasis in broilers.
PDF
