Morphological features of the late-embryo-stage gastrointestinal tract of free-roaming light ecotype Nigerian indigenous chicken.

Morphological changes in the late-embryo-stage gastrointestinal tract of Nigerian indigenous chicken were investigated using anatomical techniques. The paraffin-embedded sections were stained with haematoxylin and eosin and periodic acid Schiff-Alcian blue (pH 2.5) stains. During the late pre-hatch period, the framework of the stomach was already established, but glands were yet poorly developed. Randomly oriented pre-glandular cells in the lamina propria mucosae at embryonic day (ED) 14 became organized into elongated simple tubular glands at ED 19 and assumed adult morphology at post-hatch day (PD) 1. Acidic and neutral mucin deposits were associated with the glandular cells. In the small intestine, enterocytes of the tunica epithelialis mucosae transformed from cuboidal-shaped cells (at ED 14) to tall columnar cells (at PD 1). Short crypts of Lieberkühn, goblet cells, microfold cells and enteroendocrine cells were evident at ED 19, while the lamina propria mucosae and submucosa contained mesenchymal cells, reticular cells and isolated lymphoblasts. Similarly, the crypts, lymphoblasts, mesenchymal and reticular cells were also associated with the lamina propria mucosae and submucosa of the caecum and colorectum at ED 19. It was inferred from these findings that extensive cellular and tissue modifications occur in the gastrointestinal tract within the narrow window of the late pre-hatch period. The definitive gut tunics, epithelium, glandular tissues, immune-competent cells and tissues are formed as a result. Thus, the embryonic gut of the bird is made capable of assuming its necessary functions of food digestion, nutrient absorption, water and ion re-absorption, immune surveillance, antibody production and immune responses at hatch.

Mitochondrial dysfunction and calcium dyshomeostasis in the pectoralis major muscle of broiler chickens with wooden breast myopathy.

The incidence of wooden breast (WB) meat of commercial broiler chicken has been increasing in recent years. Histological examination found that the occurrence of WB myopathy was accompanied by the pectoralis major (PM) muscle damage. So far, the potential mechanisms are not fully understood. This study aimed to explore the underlying mechanism of the damage of WB-affected PM muscle caused by changes in mitochondrial function, mitochondrial redox status and Ca2+ homeostasis. A total of 80 market-age Arbor Acres male broiler chickens were sampled and categorized into control (CON) and WB groups based on the evaluation of myopathic lesions. PM muscle samples were collected (n = 8 in each group) for histopathological evaluation and biochemical analyses. Ultrastructural examination and histopathological changes suggested the occurrence of PM muscle damage in broiler chickens with WB myopathy. The WB group showed an increased level of reactive oxygen species and enhanced antioxidant capacities in mitochondria of PM muscle. These changes were related to impaired mitochondria morphology and mitochondrial dysfunction. In addition, abnormal expressions of Ca2+ channels led to substantial Ca2+ loss in SR and cytoplasmic Ca2+ overload, as well as Ca2+ accumulation in mitochondria, resulting in Ca2+ dyshomeostasis in PM muscle of broiler chickens with WB myopathy. Combined, these findings indicate that WB myopathy is related to mitochondrial dysfunction, mitochondrial redox status imbalance and Ca2+ dyshomeostasis, leading to WB-affected PM muscle damage.

Broiler performance correlates with gut morphology and intestinal inflammation under field conditions.

Maintaining optimal gut health is a key driver for a well-performing broiler flock. Histology of intestinal sections and quantification of villus structure can be used to evaluate gut health. While these measurements have been used in experimental models to evaluate gut health, less is known about the associations of these parameters with performance in commercial broiler farms. The objective of the present study was to evaluate possible associations of intestinal villus structure and the inflammatory condition of the gut with Ross 308 broiler performance in 50 commercial farms. On day 28 of the production round, 20 randomly selected broilers per farm were weighed, euthanized, and a duodenal section was collected to determine villus length, crypt depth and the CD3+ T-lymphocytes area percentage (CD3+ %). We found a relatively low coefficient of variance (CV) for the villus length (between farms; 9.67%, within farms; 15.97%), while the CD3+ (%) had a high CV (between farms; 29.78%, within farms; 25.55%). At flock level, the CD3+ (%) was significantly correlated with the villus length (r = -0.334), crypt depth (r = 0.523) and the villus-to-crypt ratio (r = -0.480). The crypt depth was significantly correlated with the European production index (EPI) (r = -0.450) and feed conversion ratio (FCR) (r = 0.389). At broiler level, a significant association was found between the individual body weight (day 28), CD3+ (%) and villus-to-crypt ratio. These data thus show that gut villus structure is significantly associated with bird performance under commercial conditions. RESEARCH HIGHLIGHTSGut histology parameters vary between and within farms.Broiler performance is associated with gut morphology.

Dumbbell-shaped brains of Polish crested chickens as a model system for the evolution of novel brain morphologies.

The evolutionary history of vertebrates is replete with emergence of novel brain morphologies, including the origin of the human brain. Existing model organisms and toolkits for investigating drivers of neuroanatomical innovations have largely proceeded on mammals. As such, a compelling non-mammalian model system would facilitate our understanding of how unique brain morphologies evolve across vertebrates. Here, we present the domestic chicken breed, white crested Polish chickens, as an avian model for investigating how novel brain morphologies originate. Most notably, these crested chickens exhibit cerebral herniation from anterodorsal displacement of the telencephalon, which results in a prominent protuberance on the dorsal aspect of the skull. We use a high-density geometric morphometric approach on cephalic endocasts to characterize their brain morphology. Compared with standard white Leghorn chickens (WLCs) and modern avian diversity, the results demonstrate that crested chickens possess a highly variable and unique overall brain configuration. Proportional sizes of neuroanatomical regions are within the observed range of extant birds sampled in this study, but Polish chickens differ from WLCs in possessing a relatively larger cerebrum and smaller cerebellum and medulla. Given their accessibility, phylogenetic proximity, and unique neuroanatomy, we propose that crested breeds, combined with standard chickens, form a promising comparative system for investigating the emergence of novel brain morphologies.

Dietary threonine and lysophospholipid supplement in broiler chickens: effect on productive performance, carcass variables, cecal microbiota activity, and jejunal morphology.

The objective of this experiment was to investigate the efficacy of lysophospholipid (LPL) in combination with different levels of threonine (Thr) on productive performance, jejunal morphometric variables, cecal microbial population, and carcass characteristics of male broiler chickens. Four hundred 1-day-old male broiler chicks were distributed into eight experimental groups with five replicates, each of ten birds. Factors were two levels of 0 or 0.1% Lipidol as LPL supplement and four inclusion amount of Thr (100, 105, 110, or 115% of requirements) in the diets. During 1 to 35 days, inclusion of LPL supplementation in diets improved the body weight gain (BWG) and feed conversion ratio (FCR) of broilers (P < 0.05). Besides, FCR was significantly greater in the birds fed with 100% Thr compared to the other inclusion rates of Thr (P < 0.05). The jejuna villus length (VL) and crypt depth (CD) were greater in the birds fed with LPL-supplemented diets (P < 0.05) while the greatest VH/CD and villus surface was observed in the birds fed with 105% of dietary Thr (P < 0.05). In cecal microbiota composition, Lactobacillus population was lower in broilers which received diet containing 100% Thr compared to the other group receiving more than 100% Thr (P < 0.05). In conclusion, inclusion of LPL supplements and amounts greater than Thr requirement in diet improved productive performance and jejunal morphology of male broiler chickens.

Supplementary Prebiotics, Probiotics, and Thyme (Thymus vulgaris) Essential Oil for Broilers: Performance, Intestinal Morphology, and Fecal Nutrient Composition.

This experiment was performed to evaluate the effects of selected natural feed additives (thyme extract, organic acid, probiotic, and prebiotic) on performance, intestinal morphology, and composition of fecal nutrients with two crude protein levels diet (10% reduced crude protein level and the recommended level) in broilers. In this experiment, 388 Ross-308 strain broilers from 1 to 42 days in three experimental periods including starter (1 to 10 days), grower (11 to 24 days), and finisher (25 to 42 days) were used in a completely randomized design (8 treatments, 4 replicates, and 12 chickens in 5 × 2 factorial arrangements). According to the results, use of feed additives along with both levels of crude protein had significant effects on performance, intestinal morphology, and fecal nutrient levels (P < 0.05). A 10% decrease in crude protein level of diet caused to decrease in daily weight gain and an increase in feed conversion ratio in the starting period (P < 0.05). Decreased dietary crude protein levels in growing and finishing period had insignificant effects on chicken's performance (P > 0.05). During the experiment period, the use of feed additives on diets with lower than normal crude protein levels had no effect on the average feed intake, daily weight gain, and feed conversion ratio of chickens (P > 0.05). Lower crude protein level changed the intestinal morphology (P < 0.05). The use of feed additives had significant effects on the nutrient content of feces (P < 0.05). Overall, results showed that a 10% reduction in crude protein level of diet compared to normal crude protein levels changed the intestinal morphology and nutrient content of feces while having adverse effects on the performance of chickens.

Research Note: Comparison of two methods to measure broiler tibia morphology.

The skeletal integrity of chickens is an important area of research and detailed measures are needed to better understand the influence of experimental manipulation on bone health. The objective of this experiment was to compare 2 methods to measure the superficial tibiotarsus (tibia) morphology of broiler chickens collected in the wet laboratory (WL) or from digital images (DIG). The length, width at 90%, 75%, 50%, 25%, and 10% of the length, proximal and distal head width, medial, lateral, and distal intercondylar groove depth (ID), and proximal head angle were measured on the right and left tibias collected from broilers in 2 experiments (E1, E2). In both experiments, tibias had a greater width at 90% of the length when measured with the WL method compared with the DIG method (P ≤ 0.04), while tibias measured with the DIG method had a greater length, distal ID, and widths at 10%, 25%, 50%, and 75%, of the length compared with the WL method (P < 0.0001). In E1, tibias measured with the DIG method had a greater medial, lateral, and distal ID compared with the WL method (P ≤ 0.04). In E2, compared with the DIG method, tibias measured with the WL method had a greater distal head width and lateral ID, yet a shallower distal ID (P ≤ 0.03). The use of the DIG method provided more precise measures but, due to the limitations of measures from digital images and the opportunity for more accurate measures to be collected with the WL method, the WL method is recommended to measure the superficial morphology of broiler chickens because it was more accessible and practical.

Morphometric measurements and carcass characteristics of Black Australorp, Naked Neck, and Rhode Island Red crossbreds under alternative production systems / Medições morfométricas e características de carcaça de Black Australorp, Naked Neck e Rhode Island Red crossbreds sob sistemas de produção alternativos

The present trial explained the effect of alternative production systems on growth, morphometric and carcass traits of four different chicken genotypes. The second generation of two genotypes RNN (Rhode Island Red × Naked Neck) and BNN (Black Australorp × Naked Neck) obtained by two self-crosses (RNN × RNN = RR and BNN × BNN = BB) and two reciprocal crosses (RNN × BNN = RB and BNN × RNN = BR) were evaluated in three alternative production systems (conventional cages, enriched cages, and aviary). At the 6th week of age after sexing, a total of 600 birds, comprising 150 from each crossbred with a total of 300 pullets and 300 cockerels were divided into conventional cages, enriched cages, and aviary systems having 200 birds in each.Birds were organized into 3×4 factorial arrangements under Completely Randomized Design (3 production systems × 4 genotypes × 2 sexes × 25 birds = 600 birds). Regarding genotypes, RB and BR males showed higher (p < 0.01) carcass yield, drumstick weight, breast weight, and thigh weight than BB and RR genotypes. Females of BR genotype showed higher (p < 0.01) breast weight, thigh weight and drumstick weight. As far as production systems are concerned, higher (p < 0.01) liver weight, heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight were observed in the males reared in enriched cages compared with conventional cages and aviary system. Females reared in enriched cages showed higher (p < 0.01) heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight when compared with those reared in conventional cages and aviary. It is concluded that chickens (both sexes) of BR and RB genotypes had better morphological measurements and carcass traits than those of RR and BB genotype chickens. Among alternative production systems, chickens reared in enriched cages had better traits than those of reared in conventional cages and aviary during the growing phase.

O presente estudo explicou o efeito de sistemas alternativos de produção sobre o crescimento, características morfométricas e carcaças de quatro genótipos de frango diferentes. A segunda geração de dois genótipos RNN (Rhode Island Red × Naked Neck) e BNN (Black Australorp × Naked Neck) obtida por duas autocruzes (RNN × RNN = RR e B ANN × BNN = BB) e duas cruzes recíprocas (RNN × BNN = RB e BNN × RNN = BR) foi avaliada em três sistemas de produção alternativos (gaiolas convencionais, gaiolas enriquecidas e aviário). Na 6ª semana de idade após o sexo, um total de 600 aves, compostas por 150 de cada raça cruzada com um total de 300 pullets e 300 galos, foi dividido em gaiolas convencionais, gaiolas enriquecidas e sistemas aviários com 200 aves em cada. As aves foram organizadas em 3×4 arranjos fatoriais sob projeto completamente randomizado (3 sistemas de produção × 4 genótipos × 2 sexos × 25 aves = 600 aves). Em relação aos genótipos, os machos RB e BR apresentaram maior rendimento de carcaça (p < 0,01), peso da baqueta, peso mamário e peso da coxa do que os genótipos BB e RR. As fêmeas do genótipo BR apresentaram maior (p < 0,01) peso mamário, peso da coxa e peso da baqueta. No que diz respeito aos sistemas de produção, maior (p < 0,01) peso hepático, peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa foram observados nos machos criados em gaiolas enriquecidas em comparação com gaiolas convencionais e sistema aviário. As fêmeas criadas em gaiolas enriquecidas apresentaram maior (p < 0,01) peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa quando comparadas com as criadas em gaiolas convencionais e aviárias. Conclui-se que as galinhas (ambos os sexos) dos genótipos BR e RB apresentaram melhores medidas morfológicas e traços de carcaça do que os de frangos genótipos RR e BB. Entre os sistemas de produção alternativos, [...].

Assessment of phenotypic diversity within Goliath chickens population in Benin.

Goliath chickens are a new strain of poultry that originated in the department of Zou, commune of Agbangnizoun in the Republic of Benin. The characteristics of this chicken strain have not been well studied. The purpose of this study was to characterize the phenotypic diversity of Goliath chickens in departments of Zou and Couffo. A total of 140 birds made up of 92 females and 48 males were sampled using 18 morphological descriptors. The results showed a wide variation in plumage colour within overall population with the most dominant being black (18.57%), white (17.14%) and red (16.43%). Black (21.74%) and white (20.65%) plumage dominated in females and red in males (35.42%). Coloured beaks and shanks were common in both chicken sexes. Yellow eyes were more common in females (63.04%), while red eyes were the most prevalent in males (43.75%). Comb and wattle colours were red in both sexes. Morphometrically, sexual dimorphism is very marked most of the body measurements with male birds being significantly superior. The average body weight was 3.26 kg in males and 2.78 kg in females. The population was clustered in three morphotypes according to the gradient size. Chickens from Bohicon and Agbangnizoun on the one hand, and those from Zagnanado and Toviklin on the other, formed groups 1 and 2, respectively, while group 3 included individuals from Djidja. 77.96% of observed diversity was due to variation between individuals. Molecular characterization is recommended for a thorough knowledge of the Goliath chicken strain of Benin.

Effects of coated sodium butyrate on performance, egg quality, nutrient digestibility, and intestinal health of laying hens.

This study determined the effects of coated sodium butyrate (CSB) on production performance, egg quality, nutrient digestibility, and intestinal health of laying hens. We divided a total of 800 Lohmann laying hens, aged 51 wk, into 4 treatment groups: 0 (CON), 300 (CSB1), 500 (CSB2), and 800 (CSB3) mg/kg of CSB. Each group comprised 20 birds, with 10 replicates set. A 12-wk monitoring process was conducted for each laying hen. Compared to CON, dietary supplementation of CSB did not affect the average daily feed intake or the egg weight. The CSB3 group demonstrated a linear increase in the production performance (P < 0.05), with decreased feed conversion ratio (P < 0.05). CSB2 and CSB3 exhibited markedly elevated egg mass (P < 0.05). The CSB supplementation markedly enhanced the yolk color (P < 0.05). CSB1 improved the digestibility of dry matter (P = 0.029). No significant differences were observed among dietary treatments in the duodenal morphology (P > 0.05). The three dosages of CSB reduced the crypt depth (P < 0.05) in the jejunum, whereas CSB3 exhibited an increase in the villus height (VH; P = 0.048). The CSB3 group showed a markedly elevated ileal VH (P = 0.011). CSB supplementation significantly increased the butyric acid content in the cecum (P = 0.009). The hens fed on the 800 mg/kg CSB diet showed a significant increase (P = 0.029) in butyric acid content in the ileum. The CSB3 group showed an elevation in microbial diversity (P < 0.05). Additionally, at the phylum level, the CSB3 increased the enrichment of Bacteroidetes, the CSB2 increased Firmicutes, and the abundance of Deferribacteres was increased in CSB2 and CSB3 groups (P < 0.05). An enrichment of Muribaculaceae (family) was observed in the CSB3 group. In conclusion, dietary supplementation of CSB improved production, yolk color, intestinal morphology, butyrate content, and microbial composition in laying hens.

Genomic and gene expression associations to morphology of a sexual ornament in the chicken.

How sexual selection affects the genome ultimately relies on the strength and type of selection, and the genetic architecture of the involved traits. While associating genotype with phenotype often utilizes standard trait morphology, trait representations in morphospace using geometric morphometric approaches receive less focus in this regard. Here, we identify genetic associations to a sexual ornament, the comb, in the chicken system (Gallus gallus). Our approach combined genome-wide genotype and gene expression data (>30k genes) with different aspects of comb morphology in an advanced intercross line (F8) generated by crossing a wild-type Red Junglefowl with a domestic breed of chicken (White Leghorn). In total, 10 quantitative trait loci were found associated to various aspects of comb shape and size, while 1,184 expression QTL were found associated to gene expression patterns, among which 98 had overlapping confidence intervals with those of quantitative trait loci. Our results highlight both known genomic regions confirming previous records of a large effect quantitative trait loci associated to comb size, and novel quantitative trait loci associated to comb shape. Genes were considered candidates affecting comb morphology if they were found within both confidence intervals of the underlying quantitative trait loci and eQTL. Overlaps between quantitative trait loci and genome-wide selective sweeps identified in a previous study revealed that only loci associated to comb size may be experiencing on-going selection under domestication.

Influence of fermented feed additive on gut morphology, immune status, and microbiota in broilers.

BACKGROUND: This study examined the effects of a solid-state fermented feed additive (FFA) on the small intestine histology/morphology, immunity and microbiota of broilers. Two hundred eighty-eight day-old Arbor Acre chicks, were randomly assigned to one of four groups (each group has 6 replicates, with each replicate containing 12 chickens). The negative control (NC; basal diet), the positive control (PC; basal diet +antibiotic 15 ppm), the fermented feed additive low dose (FFL; basal diet + 0.3 kg/t FFA), and the fermented feed additive high dose (FFH; 3 kg/t FFA) with Lactobacillus casei (L.casei). RESULTS: The study found that the FFH and FFL groups gained more weight (1-21d) and the FFL and PC diets had better feed conversion ratio (P < 0.05) than the NC from 0-42d. The FFH group had higher villus height (P < 0.05) in the duodenum than the PC and villus height to crypt depth ratio VH/CD compared to PC and FFL groups. The FFL chickens had greater (P < 0.05) jejunal and ileal villus height than PC and NC groups respectively. The FFL group had a higher ileal VH/CD ratio (P < 0.05). Jejunum VH/CD was higher in FFL and FFH (P < 0.05) than PC (P < 0.05). FFH had a smaller thymus than NC (P < 0.05). FFA diets also increased IL-10 expression (P < 0.05). While IL-1 and TLR4 mRNA expression decreased (P < 0.05) compared to NC. The microbiota analysis showed that the microorganisms that have pathogenic properties such as phylum Delsulfobacterota and class Desulfovibriona and Negativicutes was also significantly reduced in the group treated with FFH and PC while microorganisms having beneficial properties like Lactobacillaceae family, Lactobacillus aviarus genus and Lactobacillus spp were also tended to increase in the FFH and FFL fermented feed groups compared to the PC and NC groups. CONCLUSION: These findings suggested that the FFA diet may modulate cecal microbiota by reducing pathogenic microorganisms such as phylum Delsulfobacterota and class Desulfovibriona and Negativicutes improve beneficial microorganisms like Lactobacillaceae family, Lactobacillus aviarus genus and Lactobacillus spp. While FFA diet also affect immunity, and gene expression related to immunity.

Change in the neurochemical signature and morphological development of the parvocellular isthmic projection to the avian tectum.

Neurons can change their classical neurotransmitters during ontogeny, sometimes going through stages of dual release. Here, we explored the development of the neurotransmitter identity of neurons of the avian nucleus isthmi parvocellularis (Ipc), whose axon terminals are retinotopically arranged in the optic tectum (TeO) and exert a focal gating effect upon the ascending transmission of retinal inputs. Although cholinergic and glutamatergic markers are both found in Ipc neurons and terminals of adult pigeons and chicks, the mRNA expression of the vesicular acetylcholine transporter, VAChT, is weak or absent. To explore how the Ipc neurotransmitter identity is established during ontogeny, we analyzed the expression of mRNAs coding for cholinergic (ChAT, VAChT, and CHT) and glutamatergic (VGluT2 and VGluT3) markers in chick embryos at different developmental stages. We found that between E12 and E18, Ipc neurons expressed all cholinergic mRNAs and also VGluT2 mRNA; however, from E16 through posthatch stages, VAChT mRNA expression was specifically diminished. Our ex vivo deposits of tracer crystals and intracellular filling experiments revealed that Ipc axons exhibit a mature paintbrush morphology late in development, experiencing marked morphological transformations during the period of presumptive dual vesicular transmitter release. Additionally, although ChAT protein immunoassays increasingly label the growing Ipc axon, this labeling was consistently restricted to sparse portions of the terminal branches. Combined, these results suggest that the synthesis of glutamate and acetylcholine, and their vesicular release, is complexly linked to the developmental processes of branching, growing and remodeling of these unique axons.

Retinal ganglion cell topography and spatial resolving power of eye in the native chicken of Bangladesh / Topografía de células ganglionares de la retina y poder de resolución espacial del ojo en el pollo nativo de Bangladesh

SUMMARY: The distribution of retinal ganglion cells (RGCs) was observed in the retinal wholemount of native chicken (Gallus gallus domestricus) of Bangladesh by using light microscopy. We considered five different anatomic regions (central, nasal, temporal, dorsal, and ventral) of Nissl stained wholemount, and the RGCs were counted, plotted, and measured accordingly. The average area of the retina was 431.75 mm2 while the total number of ganglion cells was 2124431 on average. Only the central area of the retina was the peak density (10400 cells/mm2) area, signifying the acute visual area, whilst the maximum spatial resolving power was 11 cycles/degree. The overall concentration of RGCs gradually declined towards the periphery but the size of cells generally decreased towards centrally. The size of ganglion cell was not uniform (12 to 180 µm2), specifically the central retina, just above the optic disc was packed with tiny-sized cells. The number, topographic distribution, and size of RGCs in native chicken signified their domesticated or terrestrial characters, uneven visual acuteness, and possibly only the central retina was the area for fine vision as the function of RGCs.

RESUMEN: En este studio se observó la distribución de las células ganglionares en la retina (CGR) de pollo nativo (Gallus gallus domesticus) de Bangladesh mediante el uso de microscopía óptica. Consideramos cinco regiones anatómicas diferentes (central, nasal, temporal, dorsal y ventral). Las muestras de CGR se tiñeron con Nissl, posteriormente, se midieron y contó el número de células totales. El área promedio de la retina fue de 431,75 mm2, mientras que el promedio del número total de células ganglionares fue de 2124431. El área central de la retina fue el área de densidad máxima (10400 células / mm2), señalando el área visual aguda, mientras que el poder de resolución espacial máximo fue de 11 ciclos / grado. La concentración general de CGR disminuyó gradualmente hacia la periferia, sin embargo, el tamaño de las células disminuyó hacia el centro. El tamaño de las CGR no fue uniforme (12 a 180 mm2), específicamente en la retina central, por encima del disco óptico, aumentaron significativamente las células pequeñas. El número, la distribución topográfica y el tamaño de las CGR en pollos nativos determinaron las características domésticas o terrestres, agudeza visual desigual y, posiblemente, la función de las CGR, en la retina central era el área de visión fina.

The use of histológical parameters to assess intestinal and liver health on broilers challenged isolatedly and simultaneously with cyclopiazonic acid and aflatoxin / B1 El uso de parámetros histológicos para evaluar la salud intestinal y hepática en pollos de engorde desafiados de forma aislada y simultánea con ácido ciclopiazónico y aflatoxina B1

Abstract Mycotoxins contaminate agricultural commodities, which contaminates animals. These toxins can damage vital organs, such as the liver, as well as the epithelial tissue. Among these mycotoxins are aflatoxin B1 (AFB1) and cyclopiazonic acid (CPA), which can occur simultaneously in food. In broilers, mycotoxicosis has an economic impact due to several factors, such as low feed conversion rate, incidence of other diseases, and interference with reproductive capacity, all of which may lead to a public health problem. The aim of the present study was to histologically assess, through the I See Inside (ISI) method, harmful effects on broiler liver, duodenum, jejunum, and ileum in the presence of AFB1 and CPA isolatedly and simultaneously. Groups challenged with mycotoxins showed significant damage to both gut and liver fragments. All challenged-groups in all fragments impaired the parameters analyzed for intestinal epithelium. In the liver, AFB1 was predominantly harmful when the parameters were analyzed separately, but when analyzing the total ISI score, CPA was also found to be harmful to this organ. The other point analyzed was the great variation between the weights of the birds contaminated by mycotoxin while the negative control group presents a lesser variation.

Resumen Las micotoxinas contaminan los productos agrícolas, que a su vez contaminan a los animales. Estas toxinas pueden dañar órganos vitales, como el hígado y el tejido epitelial. Entre estas micotoxinas se encuentran la aflatoxina B1 (AFB1) y el ácido ciclopiazónico (CPA), que pueden hallarse simultáneamente en los alimentos. En los pollos de engorde, la micotoxicosis tiene un impacto económico debido a varios factores, como la baja tasa de conversión alimenticia, la incidencia de otras enfermedades y la interferencia de la capacidad reproductiva, que pueden llevar a un problema de salud pública. El objetivo de la presente investigación es la de evaluar histológicamente, a través del método "I See Inside" (ISI), los efectos nocivos sobre el hígado, duodeno, yeyuno e íleon de pollos de engorde en presencia de AFB1 y CPA de forma aislada y simultánea. Los grupos desafiados con micotoxinas presentaron un daño significativo tanto en el intestino como en los fragmentos del hígado. Todos los grupos tratados tuvieron alteraciones en los parámetros analizados para el epitelio intestinal. En el hígado, AFB1 fue predominantemente dañino cuando los parámetros se analizaron por separado, pero al examinar la puntuación ISI total, también se encontró que el CPA era perjudicial para este órgano. Otra cuestión que fue investigada fue la gran variación entre los pesos de las aves contaminadas por micotoxinas mientras el grupo de control negativo presentó una variación menor.

A genome-wide association analysis for body weight at 35 days measured on 137,343 broiler chickens.

BACKGROUND: Body weight (BW) is an economically important trait in the broiler (meat-type chickens) industry. Under the assumption of polygenicity, a "large" number of genes with "small" effects is expected to control BW. To detect such effects, a large sample size is required in genome-wide association studies (GWAS). Our objective was to conduct a GWAS for BW measured at 35 days of age with a large sample size. METHODS: The GWAS included 137,343 broilers spanning 15 pedigree generations and 392,295 imputed single nucleotide polymorphisms (SNPs). A false discovery rate of 1% was adopted to account for multiple testing when declaring significant SNPs. A Bayesian ridge regression model was implemented, using AlphaBayes, to estimate the contribution to the total genetic variance of each region harbouring significant SNPs (1 Mb up/downstream) and the combined regions harbouring non-significant SNPs. RESULTS: GWAS revealed 25 genomic regions harbouring 96 significant SNPs on 13 Gallus gallus autosomes (GGA1 to 4, 8, 10 to 15, 19 and 27), with the strongest associations on GGA4 at 65.67-66.31 Mb (Galgal4 assembly). The association of these regions points to several strong candidate genes including: (i) growth factors (GGA1, 4, 8, 13 and 14); (ii) leptin receptor overlapping transcript (LEPROT)/leptin receptor (LEPR) locus (GGA8), and the STAT3/STAT5B locus (GGA27), in connection with the JAK/STAT signalling pathway; (iii) T-box gene (TBX3/TBX5) on GGA15 and CHST11 (GGA1), which are both related to heart/skeleton development); and (iv) PLAG1 (GGA2). Combined together, these 25 genomic regions explained ~ 30% of the total genetic variance. The region harbouring significant SNPs that explained the largest portion of the total genetic variance (4.37%) was on GGA4 (~ 65.67-66.31 Mb). CONCLUSIONS: To the best of our knowledge, this is the largest GWAS that has been conducted for BW in chicken to date. In spite of the identified regions, which showed a strong association with BW, the high proportion of genetic variance attributed to regions harbouring non-significant SNPs supports the hypothesis that the genetic architecture of BW35 is polygenic and complex. Our results also suggest that a large sample size will be required for future GWAS of BW35.

Large-scale transcriptome sequencing in broiler chickens to identify candidate genes for breast muscle weight and intramuscular fat content.

BACKGROUND: In broiler production, breast muscle weight and intramuscular fat (IMF) content are important economic traits. Understanding the genetic mechanisms that underlie these traits is essential to implement effective genetic improvement programs. To date, genome-wide association studies (GWAS) and gene expression analyses have been performed to identify candidate genes for these traits. However, GWAS mainly detect associations at the DNA level, while differential expression analyses usually have low power because they are typically based on small sample sizes. To detect candidate genes for breast muscle weight and IMF contents (intramuscular fat percentage and relative content of triglycerides, cholesterol, and phospholipids), we performed association analyses based on breast muscle transcriptomic data on approximately 400 Tiannong partridge chickens at slaughter age. RESULTS: First, by performing an extensive simulation study, we evaluated the statistical properties of association analyses of gene expression levels and traits based on the linear mixed model (LMM) and three regularized linear regression models, i.e., least absolute shrinkage and selection operator (LASSO), ridge regression (RR), and elastic net (EN). The results show that LMM, LASSO and EN with tuning parameters that are determined based on the one standard error rule exhibited the lowest type I error rates. Using results from all three models, we detected 43 candidate genes with expression levels that were associated with breast muscle weight. In addition, candidate genes were detected for intramuscular fat percentage (1), triglyceride content (2), cholesterol content (1), and phospholipid content (1). Many of the identified genes have been demonstrated to play roles in the development and metabolism of skeletal muscle or adipocyte. Moreover, weighted gene co-expression network analyses revealed that many candidate genes were harbored by gene co-expression modules, which were also significantly correlated with the traits of interest. The results of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that these modules are involved in muscle development and contraction, and in lipid metabolism. CONCLUSIONS: Our study provides valuable insight into the transcriptomic bases of breast muscle weight and IMF contents in Chinese indigenous yellow broilers. Our findings could be useful for the genetic improvement of these traits in broiler chickens.

Uterine structure and function contributes to the formation of the sandpaper-shelled eggs in laying hens.

The avian eggshell is formed in the uterus, and eggshell quality usually decreases markedly in the late phase of hen laying cycles. Production of sandpaper-shelled eggs (SE), a category of eggs with relatively less eggshell quality, causes a great economic loss. Underlying mechanisms of SE formation, however, remain unclear. For the present study, it was hypothesized that alterations in uterine structure and function contribute to SE formation. To test this hypothesis, uterine samples were collected from 450-day-old hens that produced normal eggs (NE) and SE (based on 2-week-long assessments, n = 10) for histomorphological and transcriptome analyses. Compared with the NE group, uteri of the SE group were apparently atrophied. Furthermore, a total of 211 differentially expressed genes (DEGs) were identified in the uteri of hens of the two groups. These DEGs were clustered into 145 gene ontology terms (FDR < 0.05) and enriched in 12 KEGG pathways (P < 0.10), which are primarily related to organ morphogenesis and development, cell growth, differentiation and death, ion transport, endocrine and cell communication, immune response, and corticotropin-releasing hormones. In particular, corticotropin may be an important factor in SE formation because of effects on ion transport. Furthermore, as indicated by lesser abundances of relevant mRNA transcripts, the lesser expression of genes related to ion transport and matrix proteins also contribute to SE production because of effects on eggshell formation. In conclusion, results from this study revealed there were structural and functional differences in the hen uterus in NE and SE groups.

Preparation and characterization of decellularized rooster comb as a scaffold for tissue engineering applications.

Decellularization is a method that has been widely used in tissue engineering especially in the last 20 years. In this study decellularized rooster comb was prepared and characterized for using it as a tissue scaffold. Treatment of tissues with sodium dodecyl sulfate (SDS) and Triton X-100 as two decellularization procedures in different time points were compared according to different parameters such as cytocompatibility, cell removal, preservation of extracellular matrix (ECM), and mechanical properties to find the optimum technique. Even though there was no difference regarding to efficiency on cell removal, SDS demonstrated better results on protection of tissue morphology in comparison with Triton X-100. Therefore, in general the samples treated with SDS showed higher levels of mechanical properties and cytocompatibility in comparison with Triton X-100 applied tissues. In the cuisines of many countries, rooster comb is discarded as a waste material however, in this study it was demonstrated that decellularized rooster comb could be utilized as a cheap, easily obtainable, and biocompatible scaffold. In conclusion, it was revealed that decellularized rooster comb is a promising biomaterial for using as scaffold and it is expected to be utilized for the further studies in particular on skin tissue engineering.

Novel neuroanatomical integration and scaling define avian brain shape evolution and development.

How do large and unique brains evolve? Historically, comparative neuroanatomical studies have attributed the evolutionary genesis of highly encephalized brains to deviations along, as well as from, conserved scaling relationships among brain regions. However, the relative contributions of these concerted (integrated) and mosaic (modular) processes as drivers of brain evolution remain unclear, especially in non-mammalian groups. While proportional brain sizes have been the predominant metric used to characterize brain morphology to date, we perform a high-density geometric morphometric analysis on the encephalized brains of crown birds (Neornithes or Aves) compared to their stem taxa-the non-avialan coelurosaurian dinosaurs and Archaeopteryx. When analyzed together with developmental neuroanatomical data of model archosaurs (Gallus, Alligator), crown birds exhibit a distinct allometric relationship that dictates their brain evolution and development. Furthermore, analyses by neuroanatomical regions reveal that the acquisition of this derived shape-to-size scaling relationship occurred in a mosaic pattern, where the avian-grade optic lobe and cerebellum evolved first among non-avialan dinosaurs, followed by major changes to the evolutionary and developmental dynamics of cerebrum shape after the origin of Avialae. Notably, the brain of crown birds is a more integrated structure than non-avialan archosaurs, implying that diversification of brain morphologies within Neornithes proceeded in a more coordinated manner, perhaps due to spatial constraints and abbreviated growth period. Collectively, these patterns demonstrate a plurality in evolutionary processes that generate encephalized brains in archosaurs and across vertebrates.