The Impact of Essential Amino Acids on the Gut Microbiota of Broiler Chickens.

The research involving the beneficial aspects of amino acids being added to poultry feed pertaining to performance, growth, feed intake, and feed conversion ratio is extensive. Yet currently the effects of amino acids on the gut microbiota aren't fully understood nor have there been many studies executed in poultry to explain the relationship between amino acids and the gut microbiota. The overall outcome of health has been linked to bird gut health due to the functionality of gastrointestinal tract (GIT) for digestion/absorption of nutrients as well as immune response. These essential functions of the GI are greatly driven by the resident microbiota which produce metabolites such as butyrate, propionate, and acetate, providing the microbiota a suitable and thrive driven environment. Feed, age, the use of feed additives and pathogenic infections are the main factors that have an effect on the microbial community within the GIT. Changes in these factors may have potential effects on the gut microbiota in the chicken intestine which in turn may have an influence on health essentially affecting growth, feed intake, and feed conversion ratio. This review will highlight limited research studies that investigated the possible role of amino acids in the gut microbiota composition of poultry.

Effects of Lactobacillus reuteri and Streptomyces coelicolor on Growth Performance of Broiler Chickens.

There are well documented complications associated with the continuous use of antibiotics in the poultry industry. Over the past few decades, probiotics have emerged as viable alternatives to antibiotics; however, most of these candidate probiotic microorganisms have not been fully evaluated for their effectiveness as potential probiotics for poultry. Recent evaluation of a metagenome of broiler chickens in our laboratory revealed a prevalence of Lactobacillus reuteri (L. reuteri) and Actinobacteria class of bacteria in their gastrointestinal tract. In this study Lactobacillus reuteri and Streptomyces coelicolor (S. coelicolor) were selected as probiotic bacteria, encapsulated, and added into broiler feed at a concentration of 100 mg/kg of feed. In an 8-week study, 240 one day-old chicks were randomly assigned to four dietary treatments. Three dietary treatments contained two probiotic bacteria in three different proportions (L. reuteri and S. coelicolor individually at 100 ppm, and mixture of L. reuteri and S. coelicolor at 50 ppm each). The fourth treatment had no probiotic bacteria and it functioned as the control diet. L. reuteri and S. coelicolor were added to the feed by using wheat middlings as a carrier at a concentration of 100 ppm (100 mg/kg). Chickens fed diets containing L. reuteri and S. coelicolor mixture showed 2% improvement in body weight gain, 7% decrease in feed consumption, and 6-7% decrease in feed conversion ratios. This research suggests that L. reuteri and S. coelicolor have the potential to constitute probiotics in chickens combined or separately, depending on the desired selection of performance index.

Recent Advances in the Application of CRISPR/Cas9 Gene Editing System in Poultry Species.

CRISPR/Cas9 system genome editing is revolutionizing genetics research in a wide spectrum of animal models in the genetic era. Among these animals, is the poultry species. CRISPR technology is the newest and most advanced gene-editing tool that allows researchers to modify and alter gene functions for transcriptional regulation, gene targeting, epigenetic modification, gene therapy, and drug delivery in the animal genome. The applicability of the CRISPR/Cas9 system in gene editing and modification of genomes in the avian species is still emerging. Up to date, substantial progress in using CRISPR/Cas9 technology has been made in only two poultry species (chicken and quail), with chicken taking the lead. There have been major recent advances in the modification of the avian genome through their germ cell lineages. In the poultry industry, breeders and producers can utilize CRISPR-mediated approaches to enhance the many required genetic variations towards the poultry population that are absent in a given poultry flock. Thus, CRISPR allows the benefit of accessing genetic characteristics that cannot otherwise be used for poultry production. Therefore CRISPR/Cas9 becomes a very powerful and robust tool for editing genes that allow for the introduction or regulation of genetic information in poultry genomes. However, the CRISPR/Cas9 technology has several limitations that need to be addressed to enhance its use in the poultry industry. This review evaluates and provides a summary of recent advances in applying CRISPR/Cas9 gene editing technology in poultry research and explores its potential use in advancing poultry breeding and production with a major focus on chicken and quail. This could aid future advancements in the use of CRISPR technology to improve poultry production.

Prevalence of Multidrug-Resistant Foodborne Pathogens and Indicator Bacteria from Edible Offal and Muscle Meats in Nashville, Tennessee.

This study investigated the prevalence of antimicrobial-resistant bacteria in retail edible offal and muscle meats in Nashville, Tennessee. A total of 348 retail meats (160 edible offal and 188 muscle) were analyzed for Salmonella enterica serovar, Campylobacter, Escherichia coli, E. coli O157:H7, and enterococci. Bacteria was identified using biochemical and PCR methods. Salmonella enterica serovar (4.4% and 4.3%), Campylobacter (1.9% and 1.1%), E. coli (79.4% and 89.4%), and enterococci (88.1% and 95.7%) was detected in offal and muscle meats, respectively. Chicken liver (9.7%) was most frequently contaminated with Salmonella enterica serovar, followed by ground chicken (6.9%) and chicken wings (4.2%). No Salmonella enterica serovar was detected in beef liver, beef tripe, and ground beef. The prevalence of Campylobacter was 6.9%, 2.3%, and 1.4% in beef liver, ground beef, and ground chicken, respectively. None of the meats were positive for E. coli O157:H7. Resistance of isolates was significantly (p < 0.05) highest in erythromycin (98.3%; 99.1%), followed by tetracycline (94%; 98.3%), vancomycin (88.8%; 92.2%) as compared to chloramphenicol (43.1%; 53.9%), amoxicillin/clavulanic (43.5%; 45.7%), and ciprofloxacin (45.7%; 55.7%) in offal and muscle meats, respectively. Imipenem showed the lowest resistance (0%; 0.9%). A total of 41 multidrug-resistant patterns were displayed. Edible offal could be a source of antibiotic-resistant bacteria.

Transcriptome Analysis and Expression of Selected Cationic Amino Acid Transporters in the Liver of Broiler Chicken Fed Diets with Varying Concentrations of Lysine.

Amino acids are known to play a key role in gene expression regulation. Amino acid signaling is mediated via two pathways: the mammalian target of rapamycin complex 1 (mTORC1) and the amino acid responsive (AAR) pathways. Cationic amino acid transporters (CATs) are crucial in these pathways due to their sensing, signaling and transport functions. The availability of certain amino acids plays a key role in the intake of other amino acids, hence affecting growth in young birds. However, the specific mechanism for regulating lysine transport for growth is not clear. In this study, we analyze the transcriptome profiles and mRNA expression of selected cationic amino acid transporters in the livers of broilers fed low and high lysine diets. Birds consumed high-lysine (1.42% lysine) or low-lysine (0.85% lysine) diets while the control group consumed 1.14% lysine diet. These concentrations of lysine represent 125% (high lysine), 75% (low lysine) and 100% (control), respectively, of the National Research Council's (NRC) recommendation for broiler chickens. After comparing the two groups, 210 differentially expressed genes (DEGs) were identified (fold change >1 and false discovery rate (FDR) <0.05). When comparing the high lysine and the low lysine treatments, there were 67 upregulated genes and 143 downregulated genes among these DEGs. Analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Gene Ontology (GO) enrichment analysis show that cellular growth, lipid metabolism and lysine metabolism pathways were among the significantly enriched pathways. This study contributes to a better understanding of the potential molecular mechanisms underlying the correlation between lysine intake, body weight gain (BWG) and feed intake (FI) in broiler chickens. Moreover, the DEGs obtained in this study may be used as potential candidate genes for further investigation of broiler growth customized responses to individualized nutrients such as amino acids.

Expression of lysine-mediated neuropeptide hormones controlling satiety and appetite in broiler chickens.

Lysine is the second most limiting amino acid after methionine and is considered the most limiting amino acid for growth in poultry. Lysine requirement for broiler chickens has changed over the years. Leptin and adiponectin represent 2 adipokines that mediate metabolism by eliciting satiety effects whereas ghrelin peptide hormone influences appetite. We hypothesize that this affects growth performance of chicks. This study evaluates the effect of varying dietary lysine homeostasis on performance of broiler chickens through satiety- and appetite-mediating hormones. In 3 replications, 270 one-day-old chicks were reared for 8 wk feeding on diets comprising 0.85, 1.14, and 1.42% lysine during the starter period and 0.75, 1.00, and 1.25% lysine during the grower period. These concentrations of lysine represent 75% (low lysine), 100% (control), and 125% (high lysine) of National Research Council recommendation for broiler chickens. Feed and water were provided for ad libitum consumption. At 8 wk of age, liver, pancreas, brain, and hypothalamus tissues were collected from 18 birds randomly selected from each treatment, snap frozen in liquid nitrogen, and stored at -80°C until use. Total RNA was extracted, and cDNA was synthesized for quantitative real-time PCR assays. Low lysine concentration caused slow growth and high mortality. There was significant upregulation of ghrelin in the hypothalamus and pancreas, and leptin and adiponectin in the hypothalamus and liver, and downregulation of ghrelin in the intestines. At low lysine concentrations, adiponectin was not expressed in both pancreas and intestines. High lysine concentration exhibited increased growth, upregulation of ghrelin in the liver, and downregulation of ghrelin in the intestines, and both adiponectin and leptin in the liver. The expression of ghrelin was negatively correlated with the expression of adiponectin and leptin (P < 0.05) in the liver, hypothalamus, and pancreas. Expression of leptin was positively correlated with adiponectin in the hypothalamus and liver (P < 0.05), exhibiting satiety effects when the concentrations of lysine were low.

Effect of Aloe vera and vitamin E supplementation on the immune response of broilers / Efectos potenciales del Aloe vera y la vitamina E sobre la respuesta inmune en pollos de engorde / Efeitos potenciais da Aloe vera e vitamina E na resposta imunológica de frangos de corte

Abstract Background: herbs are among the feed supplements under investigation that could replace antibiotics to improve humoral and cellular immune response in birds. Objective: this study evaluated the potential of Aloe vera (Aloe barbadensis Miller) and vitamin E as immunostimulants on humoral and cellular immune responses in broilers. Methods: broilers were randomly assigned to three dietary treatments: a negative control (basal diet+ with no additive), basal diet + 1% Aloe vera gel in drinking water, and basal diet + 100 mg/Kg vitamin E in the feed. Antibody titers against sheep red blood cells and Newcastle disease virus were used to examine the humoral immune response, whereas cellular immune response was evaluated using the phytohemagglutinin-P tests. Results: the highest level of antibody titer against sheep red blood cells on examination days 28 and 38, and the highest response to injection of phytohemagglutinin-P on day 38 was observed in the Aloe vera gel group (p<0.05). However, the response of broilers fed Aloe vera gel was not different from those receiving vitamin E (p>0.05). In addition, the greatest antibody level against Newcastle disease virus was obtained on days 25 and 35 in the vitamin E group, with no significant difference from the Aloe vera gel group (p>0.05). Conclusion: in general, our findings demonstrated that both Aloe vera gel and vitamin E can enhance humoral and cellular immune responses of broilers, while Aloe vera gel can be used as an immunostimulant in chickens.

Resumen Antecedentes: en la industria avícola, es particularmente importante mejorar el rendimiento del sistema inmune con el objetivo de incrementar la resistencia contra patógenos. Las plantas están dentro de los suplementos alimenticios que podrían reemplazar a los antibióticos con el propósito de mejorar la respuesta inmune humoral y celular en aves. Objetivo: el presente estudio evaluó el potencial del Aloe vera (Aloe barbadensis Miller) y la vitamina E como inmunoestimulantes sobre la respuesta inmune humoral y celular en pollos de engorde. Métodos: los pollos de engorde fueron asignados aleatoriamente a tres tratamientos (dietas): un control negativo (dieta base sin aditivo), dieta base + 1% de gel de Aloe vera en el agua de bebida, y una dieta base + 100 mg/Kg de vitamina E en el alimento. Se usó la titulación de anticuerpos contra glóbulos rojos de oveja y contra la enfermedad viral Newcastle para examinar la respuesta inmune humoral. La respuesta inmune celular fue evaluada usando las pruebas de fitohemaglutinina-P. Resultados: el mayor nivel de titulación de anticuerpos contra glóbulos rojos de oveja en los días de experimentación 28 y 38, y la mayor respuesta a la inyección de fitohemaglutinina-P en el día 38 se observó en el grupo del gel de Aloe vera (p<0,05). Sin embargo, la respuesta de los pollos alimentados con gel de Aloe vera no fue diferente a la de los pollos que recibieron vitamina E (p>0,05). Además, el más alto nivel de anticuerpos contra la enfermedad viral Newcastle fue obtenida en los días 25 y 35 en el grupo que recibió vitamina E, sin diferencia significativa con respecto al grupo con gel de Aloe vera (p>0,05). Conclusión: en general, nuestros resultados demuestran que tanto el gel de Aloe vera como la vitamina E pueden mejorar la respuesta inmune humoral y celular en pollos de engorde, mientras que el gel de Aloe vera (agregado al agua) puede usarse como un inmunoestimulante en pollos de engorde.

Resumo Antecedentes: na indústria avícola, a melhoria nas respostas do sistema imunológico é importante, no sentido de aumentar a resistência contra patógenos. As ervas estão entre os suplementos que podem substituir os antibióticos na dieta com o objetivo de melhorar as respostas imunes humoral e celular. Objetivo: o presente estudo avaliou o uso potencial da Aloe vera (Aloe barbadensis Miller) e Vitamina E como imunoestimulantes sobre as respostas imunes humoral e celular em frangos de corte. Métodos: frangos de corte foram aleatoriamente distribuídos em 3 tratamentos, conforme a dieta: controle (dieta basal + sem aditivos), dieta basal + 1% de gel Aloe vera na água de bebida e dieta basal + 100 mg/Kg de vitamina E na dieta. Títulos de anticorpos contra células sanguíneas vermelhas de ovelha e o vírus da doença de Newcastle foram utilizados para avaliar a resposta imune humoral. A resposta imune celular foi avaliada através do teste da fitohemaglutinina-P. Resultados: o maior título de anticorpos contra células sanguíneas vermelhas de ovelha, aos 28 e 38 dias, e a maior resposta à injeção de fitohemaglutinina-P, aos 38 dias, foram observados no grupo recebendo o gel de Aloe vera (p<0,05). Entretanto, a resposta das aves que receberam o gel Aloe vera não foi diferente daqueles que receberam vitamina E (p>0,05). Além disso, o maior título de anticorpos contra o vírus da doença de Newcastle foi observado aos 25 e 35 dias no grupo que recebeu vitamina E sem diferença com o grupo que recebeu gel Aloe vera (p>0,05). Conclusão: em geral, nossos resultados indicam que tanto o gel Aloe vera quanto a vitamina E, podem ser utilizados para aumentar as respostas imune humoral e celular em frangos de corte, enquanto que o gel Aloe vera (adicionado à água de bebida) pode ser utilizado como um imunoestimulante em frangos.

Molecular Mechanisms of Obesity-Induced Osteoporosis and Muscle Atrophy.

Obesity and osteoporosis are two alarming health disorders prominent among middle and old age populations, and the numbers of those affected by these two disorders are increasing. It is estimated that more than 600 million adults are obese and over 200 million people have osteoporosis worldwide. Interestingly, both of these abnormalities share some common features including a genetic predisposition, and a common origin: bone marrow mesenchymal stromal cells. Obesity is characterized by the expression of leptin, adiponectin, interleukin 6 (IL-6), interleukin 10 (IL-10), monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), macrophage colony stimulating factor (M-CSF), growth hormone (GH), parathyroid hormone (PTH), angiotensin II (Ang II), 5-hydroxy-tryptamine (5-HT), Advance glycation end products (AGE), and myostatin, which exert their effects by modulating the signaling pathways within bone and muscle. Chemical messengers (e.g., TNF-α, IL-6, AGE, leptins) that are upregulated or downregulated as a result of obesity have been shown to act as negative regulators of osteoblasts, osteocytes and muscles, as well as positive regulators of osteoclasts. These additive effects of obesity ultimately increase the risk for osteoporosis and muscle atrophy. The aim of this review is to identify the potential cellular mechanisms through which obesity may facilitate osteoporosis, muscle atrophy and bone fractures.