Newborn Chicks Research Articles

Perihatch surge of thyroid hormone drives cognitive flexibility in newborn chicks

Early experience in infancy affects cognitive development. Birds, like mammals, acquire cognitive flexibility attributed to a well-developed telencephalon. Precocial chicks acquire imprintability just after hatching when thyroid hormone (T 3 ) flows into the brain and primes later learning. Here, we show that the perihatch synthesis of T 3 paralleling thyroid development is crucial for imprinting and endows newborn chicks with cognitive flexibility via a mechanism involving the nidopallium dorsocaudale, the avian “prefrontal cortex.” Imprinted chicks showed higher cognitive flexibility than those unimprinted in switching or reversal task experiments. Notably, we discovered that exogenous T 3 endowed similar flexibility in unimprinted chicks. Cognitive stimulation by a surge of thyroid hormone indicates a vertebrate tactic involving high cognitive ability for adapting to environmental changes.

Noncortical coding of biological motion in newborn chicks' brain.

Biological motion, the typical movement of vertebrates, is perceptually salient for many animal species. Newly hatched domestic chicks and human newborns show a spontaneous preference for simple biological motion stimuli (point-light displays) at birth prior to any visual learning. Despite evidence of such preference at birth, neural studies performed so far have focused on a specialized neural network involving primarily cortical areas. Here, we presented newly hatched visually naïve domestic chicks to either biological or rigid motion stimuli and measured for the first time their brain activation. Immediate Early Gene (c-Fos) expression revealed selective activation in the preoptic area of the hypothalamus and the nucleus taeniae of the amygdala. These results suggest that subpallial/subcortical regions play a crucial role in biological motion perception at hatching, paving the way for future studies on adult animals, including humans.

The Development of Object Recognition Requires Experience with the Surface Features of Objects.

What role does visual experience play in the development of object recognition? Prior controlled-rearing studies suggest that newborn animals require slow and smooth visual experiences to develop object recognition. Here, we examined whether the development of object recognition also requires experience with the surface features of objects. We raised newborn chicks in automated controlled-rearing chambers that contained a single virtual object, then tested their ability to recognize that object from familiar and novel viewpoints. When chicks were reared with an object that had surface features, the chicks developed view-invariant object recognition. In contrast, when chicks were reared with a line drawing of an object, the chicks failed to develop object recognition. The chicks reared with line drawings performed at chance level, despite acquiring over 100 h of visual experience with the object. These results indicate that the development of object recognition requires experience with the surface features of objects.

Non-competitive NMDA antagonist MK-801 prevents memory reconsolidation impairment caused by protein synthesis inhibitors in young chicks.

Introduction: Reactivation of already consolidated memory can initiate its destabilization, making the memory trace labile. Normally, this destabilization is followed by reconsolidation of the memory trace, enriched by newly acquired experience. Disrupting the reconsolidation process, for example, by inhibiting protein synthesis, impairs subsequent memory retrieval, leading to reminder-related amnesia. Previous studies in various species have shown that this impairment can be prevented by using NMDA receptor antagonists, which interfere with memory destabilization. Methods: In the present study we examined this phenomenon using a one-trial passive avoidance learning model in newborn chicks, the hypothesis being that inactivation of the NMDA-mediated transmission during memory reactivation would inhibit the memory trace labilization and thus prevent the reminder-related amnesia. Results: We found that reminder-associated administration of the NMDA receptor antagonist MK-801 or one of the protein synthesis inhibitors (anisomycin, cycloheximide, 2-deoxygalactose) each alone produced amnesia. However, when combined, injection of MK-801 before the reminder prevented amnesia induced by protein synthesis inhibitors. Discussion: We suggest that the observed paradoxical effect implicates the involvement of NMDA receptors in both protein synthesis-independent engram destabilization upon its retrieval and protein synthesismediated engram stabilization after its updating. This puzzling dual role of NMDA receptors in memory destabilization/restabilization requires further investigation.

Impact of early posthatch feeding on the immune system and selected hematological, biochemical, and hormonal parameters in broiler chickens

Under commercial conditions, chicks hatch within a 24 to 48 h window, a period known as the hatching window. Subsequently, they undergo various treatments before finally being transported to the broiler farm. These procedures may delay the chicks' access to food and water, sometimes receiving them as late as 72 h after hatching. Previous studies have indicated that fasting during this initial period is detrimental, leading to impaired body growth, compromised immune system response, and hindered muscle development. The objective of this study was to assess the impact of early posthatch feeding on immune system organs and selected hematological, biochemical, and hormonal parameters. The experiment utilized Ross 308 broiler eggs incubated under typical commercial hatchery conditions. The experimental group's eggs were hatched in HatchCare hatchers (HC) with immediate access to feed and water, while the control group's eggs were hatched under standard conditions (ST). Thirty chickens from each group were assessed on the 1st (D1), 7th (D7), 21st (D21), and 35th (D35) day after hatching. On D1, the HC group exhibited lower hemoglobin, hematocrit, and total serum protein values, suggesting that early access to water prevents initial dehydration in newborn chicks. Conversely, the ST group showed a stress reaction on D1 due to feed deprivation, leading to an almost 2-fold higher serum corticosterone concentration compared to the HC group. However, this increase did not result in a significant change in the heterophil/lymphocyte ratio. Furthermore, the HC group displayed an increase in triglyceride concentration and a decrease in HDL concentration on D1. On D7, the HC group exhibited an increased relative weight of the bursa and a higher CD4+ cell number in the cecal tonsil (CT), indicating a more rapid development of these organs resulting from early stimulation of the gastrointestinal tract. However, early feeding did not influence the numbers of Bu-1+, CD4+, and CD8+ cells or the germinal center (GC) areas in the spleen. In conclusion, early feeding contributes to the welfare of newborn chicks by reducing dehydration and stress levels and stimulating the development of gut-associated lymphoid tissue.

Effect of fecal microbiota transplantation on early intestinal immune function and histomorphology of immune organs in chicks.

Modern management of eggs causes the normal vertical transmission of microbiota from hens to be significantly reduced. The risk of environmental threats to newborn chicks is raised. The microbial community helps to mature the immune system of chicks and protect them from pathogen invasion. We still have doubts about whether transplanting the microbiota can regulate gut immunity. Using the gut microbiota of hens as an excellent resource to improve the immunity of chicks may provide new ideas for the development of the poultry industry.

Sensitivity to the role of an animated agent from observed interactions in newborn chicks (Gallus gallus).

Few month old human infants are able to detect the social roles of artificial agents and consistently choose the object behaving as 'approacher' rather than 'repulser'. This preference has been considered evidence of a pre-linguistic and pre-cultural origin of the social mind. Similar preferences have not been described in other species, though comparative data could help clarify the nature of this phenomenon and its evolutionary origin. In this study, we investigated sensitivity to the social role of an artificial agent in domestic chicks. Birds offer an excellent model to study the evolutionary roots of cognitive abilities, since they separated from mammals over 300 Ma. Moreover, the investigation of newly hatched chicks allows control for previous experience. After being exposed to computer-presented animations depicting an interaction among two agents, chicks underwent a free choice test among those same objects. While no initial evidence of a clear preference emerged from the planned analysis, chicks in the experimental condition showed a preference for the 'approacher' when controlling for side bias, mirroring human infants behaviour. This suggests the existence of an early ability to discriminate agents from their interactions, independent from any social experience.

The Effects of In Ovo Feeding of Selenized Glucose on Selenium Concentration and Antioxidant Capacity of Breast Muscle in Neonatal Broilers.

This study aims to investigate the impacts of in ovo feeding (IOF) of selenized glucose (SeGlu) on selenium (Se) level and antioxidant capacity of breast muscle in newborn broilers. After candling on 16day of incubation, a total of 450 eggs were randomly divided into three treatments. On the 17.5th day of incubation, eggs in a control treatment were injected with 0.1mL of physiological saline (0.75%), while the 2nd group and 3rd group were supplied with 0.1mL of physiological saline containing 10μg Se from SeGlu (SeGlu10 group) and 20μg Se from SeGlu (SeGlu20 group). The results showed that in ovo injection in both SeGlu10 and SeGlu20 increased the Se level and reduced glutathione concentration (GSH) in pectoral muscle of hatchlings (P < 0.05). Compared with the control group, the SeGlu20-treated chicks significantly enhanced the activity of the superoxide dismutase (SOD) and mRNA expression of NAD(P)H quinone dehydrogenase 1 (NQO1) in breast muscle, while there was upregulation in mRNA expressions of glutathione peroxidase 1 (GPX-1) and thioredoxin reductase 1 (TrxR1) and higher total antioxidant capacity (T-AOC) in SeGlu10 treatment (P < 0.05). However, no significant difference on enzyme activities of glutathione peroxidase (GR), glutathione reductase, thioredoxin reductase, concentration of malondialdehyde, and free radical scavenging ability (FRSA) of superoxide radical (O2-•) and hydroxyl radical (OH•) was observed among the three treatments (P > 0.05). Therefore, IOF of SeGlu enhanced Se deposition in breast muscle of neonatal broilers. In addition, in ovo injection of SeGlu could increase the antioxidant capacity of newborn chicks possibly through upregulating the mRNA expression of GPX1, TrxR1, and NQO1, as well as the SOD activity.

Economic Order Quantity for Growing Items with Mortality Function under Sustainable Green Breeding Policy

Determining the optimal slaughter age of fast-growing animals regarding the mortality rates and breeding costs plays an important and major role for companies that benefit from their meat. Additionally, the effects of carbon dioxide (CO2) emissions during the growth cycle of animals are a significant concern for governments. This study proposes an economic order quantity (EOQ) for growing items with a mortality function under a sustainable green breeding policy. It assumes that CO2 production is a practical polynomial function that depends on the age of the animals as well as the mortality function. The aim of the model is to determine the optimal slaughter age and the optimal number of newborn chicks, purchased from the supplier, to minimize the total costs. We propose an analytical approach, with five simple steps, to find the optimal solutions. Finally, we provide a numerical example and some model management insights to help practitioners in this area.

Efficacy of TurmiZn, a Metallic Complex of Curcuminoids-Tetrahydrocurcumin and Zinc on Bioavailability, Antioxidant, and Cytokine Modulation Capability

Complexes of curcumin with metals have shown much-improved stability, solubility, antioxidant capability, and efficacy when compared to curcumin. The present research investigates the relative bioavailability, antioxidant, and ability to inhibit inflammatory cytokine production of a curcuminoid metal chelation complex of tetrahydrocurcumin-zinc-curcuminoid termed TurmiZn. In vitro uptake assay using pig intestinal epithelial cells showed that TurmiZn has an ~3-fold increase (p ≤ 0.01) in uptake compared to curcumin and a ~2-fold increase (p ≤ 0.01) over tetrahydrocurcumin (THC). In a chicken model, an oral 1-g dose of TurmiZn showed a ~2.5-fold increase of a specific metabolite peak compared to curcumin (p = 0.004) and a ~3-fold increase compared to THC (p = 0.001). Oral doses (5 g/Kg) of TurmiZn in rats also showed the presence of curcumin and THC metabolites in plasma, indicating bioavailability across cell membranes in animals. Determination of the antioxidant activity by a 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging assay indicated that TurmiZn was about 13x better (p ≤ 0.0001) than curcumin and about 4X better (p ≤ 0.0001) than THC, in reducing free radicals. In vitro experiments further showed significant (p ≤ 0.01) reductions of lipopolysaccharide (LPS)-induced proinflammatory cytokines such as interleukin (IL) IL-6, IL-8, IL-15, IL-18, and tumor necrosis factor (TNF)-alpha, while showing a significant (p ≤ 0.01) increase of granulocyte-macrophage colony-stimulating factor (GM-CSF) in dog kidney cells. In vivo cytokine modulations were also observed when TurmiZn was fed for 6 weeks to newborn chickens. TurmiZn reduced IL-1 and IL-6, but significantly reduced (p ≤ 0.01) IL-10 levels while there was a concurrent significant (p = 0.02) increase in interferon gamma compared to controls. Overall, these results indicate that TurmiZn has better bioavailability and antioxidant capability than curcumin or THC and has the ability to significantly modulate cytokine levels. Thus, TurmiZn could be an excellent candidate for a novel ingredient that can be incorporated into food and supplements to help overall health during the aging process.

A spontaneous gravity prior: Newborn chicks prefer stimuli that move against gravity

A spontaneous gravity prior: Newborn chicks prefer stimuli that move against gravity

A spontaneous gravity prior: newborn chicks prefer stimuli that move against gravity.

At the beginning of life, inexperienced animals use evolutionary-given preferences (predispositions) to decide what stimuli to attend and approach. Stimuli that contain cues of animacy, such as face-like stimuli, biological motion and changes in speed, are particularly attractive across vertebrate taxa. A strong cue of animacy is upward movement against terrestrial gravity, because only animate objects consistently move upward. To test whether upward movement is spontaneously considered attractive already at birth, we tested the early preferences of dark-hatched chicks (Gallus gallus) for upward- versus downward-moving visual stimuli. We found that, without any previous visual experience, chicks consistently exhibited a preference to approach stimuli that move upward, against gravity. A control experiment showed that these preferences are not driven by avoidance of downward stimuli. These results show that newborn animals have a gravity prior that attracts them toward upward movement. Movement against gravity can be used as a cue of animacy to orient early approach responses in the absence of previous visual experience.

Testing Honey on Chicken Embryos as Candidates for Herbal Medicine in Indonesia

The nutrients in honey had function as antioxidants. The aim of this study was to testing honey on chicken embryos as candidates for herbal medicine in Indonesia. This study used treatment method, consisting of 6 (six) doses of honey products. The solution volume of each treatment dose was fixed at 10 l/egg via the route to the air bag. At the age of 13 days, embryo morphology and possible abnormalities were observed in all treatments. Each two eggs are cracked. The remainder was continued by incubation in the incubator until day 21. During this time the eggs were observed and the number was recorded to find out which eggs would die and which eggs would hatch at the end of the incubation period. Newborn chicks (DOC) were weighed and observed for possible morphological abnormalities. From the results of the research conducted, it was found that the percentage of viable chicken eggs sprouted after being injected with honey (days 13-21 after inoculation) and the morphology of chicken embryos after being injected with honey. Chicken Embryo Weight and Body Length Measurements were carried out in chicken embryos. The conclusion of the study is that propolis from honey products can be used as herbal medicine.

SUPLEMENTACIÓN DE OXÍGENO EN LA INCUBACIÓN DE HUEVOS FÉRTILES DE GALLINA CRIOLLA

This study evaluated the effect of oxygen supplementation on the hatchability of fertile eggs of the Creole hen at 2718 meter above sea level. The experiment was carried out with 1408 hatching eggs obtained at age different of the breeders (25, 30, 34 and 38 wks.). Eggs were assigned to four incubators with different periods of oxygen supplementation: treatment without oxygen supplementation (SS) and oxygen supplementations at week 1, week 3, and weeks 1 and 3. Body weight, hematocrit, and hemoglobin were determined of embryos of 18 days incubation and newborn chicks. Hatching percentage was calculated based on the number of fertile eggs. Early and late embryonic mortality was determined. From the fertile eggs supplemented with oxygen during the first and third weeks, a higher percentage of hatched chicks (82.60%) and lower embryonic mortality were obtained. In the group SS, a low percentage of hatched chicks (28.32%) and high embryonic mortality were found. Oxygen supplementation to fertile creole hen eggs under hypobaric conditions in the Cajamarca valley did not increase hemoglobin concentration or improve body weight of hatched chicken.

Central dopaminergic, serotoninergic, as well as GABAergic systems mediate NMU-induced hypophagia in newborn chicken

Aim Dopaminergic, serotoninergic, and GABAergic systems influence feeding; however, it is unknown how these chemicals interact with neuromedin U (NMU)-induced feeding in birds. In the current study, ten trials were conducted to determine the links between the above-mentioned systems and NMU. Materials and Methods In the foremost experimentation, chickens were given intracerebroventricularly injections of NMU (0.1, 1, and 10 µg). NMU (10 µg), SCH23390 (5 nmol), a D1 receptor antagonist, and NMU + SCH23390 were administered in the second experiment. In subsequent experiments, instead of SCH23390, were applied AMI-193 (5 nmol D2 receptor antagonist), NGB2904 (6.4 nmol D3 receptor antagonist), L-741,742 (6 nmol D4 receptor antagonist), 6-OHDA (2.5 nmol dopamine inhibitor), SB242084 (5-HT2c receptor antagonist, 1.5 μg), 8-OH-DPAT (5-HT1A receptor agonist, 15.25 nmol), picrotoxin (GABAA receptor antagonist, 0.5 μg), and CGP54626 (GABAB receptor antagonist, 20 ng). Then, cumulative intake of food was recorded for 2 h. Results According to the results, NMU reduced feeding when compared to the control group (p < 0.05). The NMU-induced hypophagia was reduced with co-injection of NMU and SCH23390 (p < 0.05). Hypophagia was diminished with NMU and AMI-193 (p < 0.05). NMU + NGB2904 and NMU + L-741,742 co-injections had no influence (p > 0.05). 6-OHDA reduced the hypophagia (p < 0.05). NMU and SB242084 decreased the hypophagia (p < 0.05), whereas NMU and 8-OH-DPAT had no effect (p > 0.05). The effects were amplified with picrotoxin (p < 0.05). NMU with CGP54626 had no influence on the hypophagia (p > 0.05). Conclusion Thus, NMU-induced hypophagia is probably mediated by D1/D2, 5-HT2c, and GABAA receptors in neonatal chicks.

Resistance and Pathogenicity of Salmonella Thompson Isolated from Incubation End of a Poultry Farm.

Simple SummaryNon-typhoid Salmonella is the general term of Salmonella other than typhoid and paratyphoid, which often causes foodborne gastroenteritis in humans, but some serotypes have been proved to be pathogenic to poultry. Salmonella Enterica and Salmonella Typhimurium are the common serotypes pathogenic to poultry and have been systematically studied, but other serotypes have rarely been studied. During Salmonella surveillance in farms, we discovered by chance that Salmonella Thompson, a common non-typhoid Salmonella, is also pathogenic to avian embryos. Therefore, this study aimed to explore antimicrobial resistance and pathogenicity of clinical S. Thompson. Firstly, we found that the core-genome multilocus sequence typing of 14 clinical S. Thompson was consistent with two strains of S. Thompson from humans in China. Secondly, the antimicrobial resistance gene analysis demonstrated that all strains carried the polymyxin resistance gene mcr-9, which had not appeared resistance phenotype. Meanwhile, many essential virulence genes were also found in each S. Thompson isolate. Finally, the bacterial inoculation experiment revealed that clinical S. Thompson was highly pathogenic to newborn chicks after yolk sac inoculation. This study suggests that Salmonella Thompson can circulate between humans and poultry farms and transmit drug resistance genes and demonstrated that Salmonella Thompson is highly pathogenic to chicks and should be guarded against in the hatching stage of poultry farms.Salmonella Thompson, an important foodborne pathogen, is rarely found to be pathogenic to poultry. Accidentally, S. Thompson was found to be pathogenic to embryos of white feather broiler at a poultry farm in China. Therefore, this study aimed to explore antimicrobial resistance and pathogenicity of clinical S. Thompson isolated from dead poultry embryos. The phylogenetic tree based on 16S rRNA and seven housekeeping genes showed that the 14 clinical S. Thompson were closely related. The core-genome multilocus sequence typing of 14 clinical S. Thompson based on whole-genome sequencing was cgST-12774, consistent with the only two strains of S. Thompson from humans in China as reported in the NCBI database. The antimicrobial resistance gene analysis demonstrated that all strains carried aac(6′)-Iaa and the polymyxin resistance gene mcr-9. Antimicrobial sensitivity tests for 18 antibiotics showed that S. Thompson isolates displayed resistance against streptomycin (100%), ampicillin (35.7%), and doxycycline (14.3%), but sensitivity to polymyxin B, proving that the mcr-9 gene had not appeared resistance phenotype. Virulence genes Salmonella pathogenicity island (SPI) SPI1-5, type I fimbriae gene (fimA), flagellar assembly genes (bcfC, flhD, fliA, fliC, fljB, flgK, and lpfC), and other virulence genes (iroN, pagC, and cigR) were found in each S. Thompson isolate. Additionally, the bacterial inoculation experiment with 1-day-old chicks revealed that clinical S. Thompson was highly pathogenic to newborn chicks after yolk sac inoculation. This study highlighted that the S. Thompson isolated from poultry embryos and the S. Thompson causing human foodborne diarrhea in some parts of China belong to the same cgMLST typology (cgST-12774) and showed the pathogenicity of this clinical S. Thompson to chicks.

Implementation of automatic lighting and heating system for poultry farm using Arduino

In the field of poultry science, automation technologies can be highly helpful. Using an automatic heating and lighting system for newborn chickens helps to sustain a temperature that is ideal for their development both during the day and during the cold winter nights. A self-regulating temperature device that uses a fixed point or value to regulate the temperature of a lab or room is known as an automatic heat control system. The research study aimed to manage and control heat and lighting system automatically using Arduino. The user will set the desired temperature, which is then compared to the temperature of the poultry house as determined by a temperature sensor, and the device responds by automatically turning on the heater/lamp based on the temperature differential. Time and temperature will be registered on the SD card. The heater will turn on if the temperature falls below the fixed limit. Dip Trace, a circuit modelling program used to create electronic systems and PCBs, was used to create the device. The ATmega328p microcontroller and Arduino software were used to code. To provide a controlled voltage to most of the active devices in the system design circuit, a 5v DC power supply was added. For data recording, an SD card and an RTC are attached to the circuit. This method maintains a warm environment for baby chicks while also providing light. This technology regulates the temperature of the surroundings without the need for human intervention. The android mobile app may be used to monitor and check the temperature status of poultry homes at any time via a Bluetooth connection.

Transport Stress Induced Cardiac NO-NOS Disorder Is Mitigated by Activating Nrf2/HO-1/NQO1 Antioxidant Defense Response in Newly Hatched Chicks.

With the development of the intensive poultry industry, the health problems of chickens caused by transportation have attracted more and more attention. Transport stress reduces performance, immune function, and meat quality in chicks, which has become one of the most important factors that endanger the development of the poultry industry. Currently, studies on the effects of transport stress have mainly focused on the performance of livestock and poultry to be slaughtered. However, the effects of transport stress on heart damage and oxidative stress in newborn chicks have not been reported. In this study, we selected newborn chicks as the object. This study was intended to explore the effects of transport stress on the heart damage of newly hatched chicks. The findings suggested that transport stress could cause oxidative stress in the hearts of newly hatched chicks by increasing the levels of malondialdehyde (MDA), hydrogen peroxide (H2O2) and decreasing the contents of Total antioxidant capacity (T-AOC), and the activities of antioxidant enzymes (SOD), together with increasing the activities of antioxidant enzymes (Catalase (CAT) and Glutathione S-transferase (GST)). Transport stress disrupted the balance between oxidation and antioxidant systems. The Nrf2 signaling pathway was activated by transport stress and triggered the transcription of antioxidant signaling. In short, transport stress-induced nitric oxide (NO)—nitric oxide synthases (NOS) system metabolic disorders and cardiac oxidative stress are mitigated by activating the nuclear factor-erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)/NAD(P)H quinone oxidoreductase-1 (NQO1) antioxidant defense response in newly hatched chicks.

How Egg Storage Duration Prior to Incubation Impairs Egg Quality and Chicken Embryonic Development: Contribution of Imaging Technologies.

Storing fertilised eggs prior to incubation is a frequent practice in commercial hatcheries to coordinate activities and synchronise hatchings. However, the conditions used to store eggs can have major impacts on egg quality and the subsequent viability of chicken embryos. While storage temperatures of 16–18°C are classically used in hatcheries, the duration of storage varies from three to more than 10 days. We explored the effect of storage duration (zero, three or 10 days; D0, D3 and D10, respectively) at 16°C, 80% relative humidity (RH) on egg quality (Broiler, Ross 308), using computed tomography (CT) and classical measurements (egg weight, eggshell strength, egg white pH, Haugh units, yolk index and colour). The results revealed that a storage duration of up to 10 days negatively affected some egg quality traits (yolk index and volume, air chamber volume and egg white pH). Eggs stored for three or 10 days were further incubated for 11, 13 or 15 days (37.8°C, 55% RH). Eggs were analysed by magnetic resonance imaging (MRI) and CT to assess the development of the embryo and internal egg changes occurring during incubation. First, data showed that the fertility and sex ratio of eggs were not affected by storage duration. However, the mortality of viable eggs was increased in the D10 group compared to the D3 group. Results of non-invasive imaging technologies revealed that the storage of eggs for 10 days impaired embryo growth as early as 11 days of incubation (decrease in brain and embryo volumes). Collectively, these data provide new evidence that the duration of egg storage negatively affects embryonic growth. They further corroborate that this parameter is likely to be crucial to synchronising embryonic stages and maybe reducing the hatching window, hence limiting the time spent by newborn chicks in hatchers. In addition, our results highlight that CT and MRI imaging technologies are useful non-invasive tools to evaluate egg quality prior to incubation and the impact of storage (or incubation) practices on developmental growth of the embryo.

Identification of the intermediate host of Gongylonema sp., the etiological agent of the necrotic oropharyngeal disease of the Scops owl (Otus scops).

Since 1997, fledgling Scops owls (Chordata: Strigidae) have been brought to the Brinzal Owl Rescue Centre (Madrid, Spain) with severe lesions in their oral cavities. Lesions consist of the presence of proliferative necrotic material in the oral cavity resulting in white plaques, which can lead to death by starvation. This disease has been detected in owls only within the limits of the city of Madrid. The etiologic agent has been identified as Gongylonema sp. (Nematoda: Spirurida), a nematode genus that includes a coprophagous arthropod as intermediate host in its cycle. The aim of this study was to identify the intermediate host of the parasite. Our work was structured in four component phases: i) Diet study of newborn chicks; ii) trapping arthropods that could be intermediate hosts; iii) molecular detection of the parasite in the selected arthropods: and iv) molecular characterization of the detected parasites by amplifying the cox1 gene. Four male owls were radio-tagged in order to locate their nests and a camera trap was placed to identify the prey brought to the owlets. Secondly, the arthropods present in the hunting areas of the owls were sampled, identified and analyzed by real time PCR (rtPCR). Only oriental cockroaches, B. orientalis (Arthropoda: Blattodea), were positive by rtPCR detection of Gongylonema sp. (66.7%). The nematodes obtained from cockroaches had a 99.8% identity of the cox1 gene with the Gongylonema sp. isolated for the first time in a Scops owl. Furthermore, these sequences only showed an <89% identity with all the other Gongylonema sequences available in the GenBank database. We conclude that the oriental cockroach should be considered as an intermediate host of the etiologic agent of NOD.