Brooding Research Articles

Bottom-up effects of nutrient solutions on grape-grape phylloxera (Daktulosphaira vitifoliae) interaction.

Fertilizers generally influence the nutritional quality or defense ability of the plants, which can indirectly cause an increase in populations of herbivorous insect pests such as grape phylloxera, Daktulosphaira vitifoliae (Homoptera: Phylloxeridae, Fitch). The effects of nutrient solutions on grape-grape phylloxera interactions were analyzed using five concentrations (nitrogen content: 15, 30, 60, 120, and 180mg/L) of Hoagland's nutrient solution to irrigate Vitis vinifera L. × Vitis labrusca L. (Kyoho). Life table variables and life history variables showed a hump-shaped or an inverted hump-shaped curve as nutrient input level increased. Sixty microgram per liter treatment resulted in the greatest longevity and egg incubation, shortened the nymph duration and significantly increased the adult lifespan. Overall, both excessive and insufficient nutrient inputs curbed growth and multiplication of D. vitifoliae. These results provide a theoretical basis for vineyards for amending fertilizer inputs to prioritize the prevention and control of this pest.

Finding a balance: Reproductive trade-offs in parasitic isopods of the family Cymothoidae.

In this study conducted along the coast of Odisha, India, reproductive trade-offs in isopods of the family Cymothoidae were investigated, focusing on the relationship between the number vs. volume of eggs and the percentage of brood to body volume. Ovigerous females from species with substantial sample sizes (n > 30) were analyzed to understand their survival strategies. The findings highlight distinct strategies among different parasite types within Cymothoidae. Buccal parasites such as Cymothoa frontalis and Cymothoa indica, along with branchial parasites like Joryma sawayah and Agarna malayi, generally produced a higher number of smaller eggs, except for A. malayi, which produced fewer but larger eggs. In contrast, the external body surface-attaching parasite, Nerocila orbignyi, was observed to produce fewer eggs of larger size. Across all parasite types (intraspecific), there was a statistically significant negative correlation between egg number and egg volume (p < 0.05). Buccal parasites were observed to have the highest percentage of marsupium volume relative to body volume, indicating a strategy to maximize egg storage. Conversely, external body surface-attaching parasites had the lowest percentage, possibly reflecting adaptation to a different reproductive environment. Additional observations revealed anatomical adaptations in all the studied isopod species which include the shift of the alimentary canal to the dorsal side to accommodate the development of the marsupial sac for egg incubation. In summary, these findings illustrate how parasitic isopods of the family Cymothoidae manage trade-offs between reproductive potential and success, crucial for their species' continuity and survival strategies in coastal ecosystems.

Extraction and evaluation of chitosan as an insecticide against saw-toothed grain beetle, &lt;i&gt;Oryzaephilus surinamensis&lt;/i&gt; L. (Coleoptera: Silvanidae)

Rice samples infested with saw-toothed grain beetles have been collected from a local market in the city of Kirkuk/Iraq. The study was conducted in Kirkuk during the period 15 December 2023 to 25 April 2024, at College of Pure Sciences at the University of Kirkuk, Iraq. Chitosan was utilised in the study to examine its toxic effects at three different concentrations (0.5, 1.0, 1.5 ppm) on the life cycle of the saw-toothed grain beetle, focusing on oviposition rate, duration of larval and pupal stages, and mortality rate of its adults. The chemical demonstrated a substantial effect in lowering the number of eggs laid as the concentration increased, with the control treatment registering the highest oviposition rate of 314.14 eggs compared to 209.31, 117.03, and 61.12 eggs for chitosan concentrations of 0.5, 1.0, and 1.5 ppm, respectively. The shortest egg incubation period recorded was 8.17 days, Incubation times for chitosan treatments increased significantly to 9.66, 11.69, and 14.00 days for concentrations of 0.5, 1.0, and 1.5 ppm, respectively, demonstrating an inverse association with concentration levels. Furthermore, the emergence rate of beetles decreased as concentration increased. The emergence counts for the chitosan treatments at concentrations of 0.5, 1.0, and 1.5 ppm dropped to 133.11, 55.69, and 30.12 beetles, respectively, with the control treatment having the highest average emergence of 289.43 beetles. The larval stage duration showed a direct proportionality with chitosan concentrations, with the 1.5 ppm concentration marking the longest larval duration at 22.00 days, significantly surpassing all other concentrations. The control treatment recorded the shortest duration at 13.56 days, whereas 0.5 and 1.0 ppm concentrations resulted in duration of 17.19 and 19.66 days, respectively. For the pupal stage, significant differences were observed with increasing chitosan concentration; the control treatment displayed the shortest pupal duration at 4.33 days. A direct relationship was found between the concentrations and pupal stage duration, reducing the period to 6.00, 7.59, and 9.07 days for concentrations of 0.5, 1.0, and 1.5 ppm, respectively. Chitosan exhibited significant differences from the second day of the experiment, as the mortality rate increased with concentration and over time. The concentration of 1.5 ppm showed the highest mortality rate at 98.62% after 16 days, whereas the control treatment recorded the lowest rate at 33.17%. Based on the results of the current study, chitosan can be utilized as an effective pesticide for controlling stored-product pests, particularly the saw-toothed grain beetle.

Extraction and Evaluation of the Effectiveness of Chitosan as Insecticides on the Immature Stages of the Saw-Toothed Grain Beetle Oryzaephilus Surinamensis L. (Coleoptera: Silvanidae)

This study aimed to collect samples of amber rice infected with the saw-toothed grain beetle from local markets in Kirkuk city during 13 December 2023 to 25 April 2024, and the experiments were conducted in the laboratories of the College of Education for Pure Sciences at Kirkuk University from February to April 2024. The toxic effects of chitosan were studied at three different concentrations: 0.5, 1.0, and 1.5 ppm on the immature stages of the saw-toothed grain beetle. The substance exhibited significant effects on the immature stages of the insect , recording the shortest egg incubation period with an average of 8.17 days, while chitosan treatment showed a significantly longer periods of 9.66, 11.69, and 14.00 days for concentrations of 0.5, 1.0, and 1.5 ppm respectively. The larval stage duration had a direct proportionality with the chitosan concentrations, where the 1.5 ppm concentration registered the longest larval period of 22.00 days, as opposed to the control which recorded the shortest period of 13.56 days, and the 0.5 and 1.0 ppm concentrations recorded durations of 17.19 and 19.66 days respectively. In the pupal stage, significant differences were found when the chitosan concentration was increased, with the control treatment having the shortest pupal stage duration of 4.33 days; a direct correlation was found between the concentrations and the pupal stage duration, which decreased to 6.00, 7.59, and 9.07 days for the 0.5, 1.0, and 1.5 ppm concentrations, respectively.

Effect of egg incubator temperature on sex differentiation in Korat chickens

The effect of incubator temperature on sex differentiation in Korat chickens was investigated. The experiments were divided into two sets: temperature applied throughout the entire incubation period and temperature applied during certain periods (days 3-6 of incubation) by either increasing above the standard or decreasing below the standard temperature. In each experiment, 300 Korat chicken eggs were separated into three groups of 5 repetitions, with 20 eggs in each group. This was done using a completely randomized design for each experiment: a group using a temperature below the standard for incubation (36.0°C), a group using the standard incubation temperature (37.7°C), and a group using a temperature above the standard for incubation (38.0°C). W chromosomes were detected at hatch; histology examined reproductive structures after 35 days. Increasing the temperature to 38.0°C throughout the entire incubation period resulted in no significant difference in hatching rates compared to the standard temperature (P>0.05). Raising the temperature to 38.0°C throughout the entire incubation and during certain periods resulted in changes in the reproductive structure of chickens, leading to a mismatch between chromosomal and gonadal sex, observed at 9.7% and 5.9% of individuals with W chromosomes possessed testes, indicating a mismatch between chromosomal and gonadal sex. However, decreasing the temperature to 36.0°C throughout the incubation period resulted in lower hatching rates compared to the standard temperature (P<0.05). Incubating eggs at 36.0°C for specific periods resulted in 19.4% of genetic males developing ovaries instead of testes. The presence of ovaries in individuals without W chromosomes indicated this mismatch. The results of this study provide evidence that temperature plays a role in sex differentiation in Korat chickens, as demonstrated by the detection of W chromosomes and histological studies of testes and ovaries. Moreover, this study presents the first evidence in broilers that temperature can affect sex differentiation.

Gene expression in the hypothalamic-pituitary-thyroid axis in Seriola rivoliana early larvae development at different temperatures

We analyzed the expression of genes involved in the hypothalamic-pituitary-thyroid axis (HPT-axis) in the longfin yellowtail Seriola rivoliana early larva, including temperature effects (22, 26 and 28 °C) and days of development (day one, day two, and day six after hatching). We aimed to determine if egg and larval incubation at different temperatures could disrupt this critical endocrine axis, which, in an aquaculture context, it could provoke mortality during early metamorphosis. There was a significant interaction between temperature and developmental timing on the relative expression of thyrotropin releasing hormone (trh). Larvae at 22 °C was the longest and increased more trh expression than larvae at higher temperatures. Interestingly, thyrotropin stimulating hormone (tsh) was highly expressed after hatching. Subsequently, it was downregulated at any temperature at least until day four, suggesting a temporal inhibition of the HPT axis. Therefore, we suggest that tsh-binding (tshr) to follicles should have occurred from hatching, creating a further “cascade effect” of upregulation of larval thyroglobulin (tg) from day two in a temperature-dependent manner. Consequently, new thyroid hormones should have been produced after yolk sac absorption. The above may indicate a narrow window of larval survival, where the larval transition from endogenous to exogenous feeding would depend on the correct timing to synthesize tg. Temperature significantly affected the expressions of deiodinase 1 (dio1-downregulated) and deiodinase 2 (dio2-upregulated) after hatching. The expressions of thyroid receptors alpha (trα) and beta (trβ) remained constant after hatching without significant effects of temperature and days of development. Then, the differential expression on day six showed that all HPT-axis transcripts increased their expressions as larvae developed, which suggested a functional HPT. Finally, there was no evidence that any temperature would disrupt the endocrine’s larval axis, which indicated that the longfin yellowtail has a wide temperature adaption. Nevertheless, based on tg upregulation, we suggest that larvae should be maintained around 25–26 °C after hatching for a better chance of survival and development.

Internet of Things Based Water Quality Control System

Fish incubation, which involves the hatching of fish eggs, represents the process of embryogenesis until the embryo emerges from its protective shell. This intricate developmental journey is influenced by a combination of internal and external factors. External factors can be influenced by water quality that is not suitable for hatching fish eggs. Water quality, which includes temperature, dissolved oxygen, light intensity, salinity, and pH, is an important and limiting factor for living creatures that live in water, including chemical, biological, and physical factors. Poor water quality can prevent fish eggs from hatching and even cause death. The primary objective here is the creation of an Internet of Things (IoT)-based system designed for controlling water quality during fish incubation. This system is intended to aid fish farmers in effectively control the environmental conditions within their incubation ponds. The method used in designing IoT device is research and development, and it uses the Arduino Mega microcontroller as the main device to run pH sensors, turbidity sensors, oxygen sensors, temperature sensors, and relay modules. Water Quality Control System The fish incubation was successful. The average time needed to change the water temperature from 28.5 to 29 degrees Celsius is 4 minutes and 7 seconds; change the dissolved oxygen level from 11 to 11.5 is 3 minutes and 33 seconds; change the pH value of the water from 6.9 to 7.1; and maintain turbidity below 5 with an average time of 5 minutes and 58 seconds. Controlling water quality can speed up the fish egg incubation process for 8 hours.

Effect of temperature on the embryonic and larvae development of discus fish Symphysodon aequifasciatus and time of first feeding.

This study aimed to analyze the influence of different temperatures on the embryonic and larval development of discus fish Symphysodon aequifasciatus and determine the time required for the beginning of exogenous feeding. Eggs and larvae were obtained from natural spawns and distributed in five treatments: 24.0, 26.0, 28.0, 30.0, and 32.0°C. To assess the developmental stages and embryonic structures, samples were taken at regular intervals and checked under an optical microscope. At the end of the experimental period, statistical analysis was performed, followed by Tukey's test. As a result, it was possible to observe the significant effects of temperature on the variables. It was noted that the temperature accelerated the embryonic and larval development of the discus and also contributed to a reduction in the time between the incubation period and the feeding transition. It was also noted that the incubation of eggs and larvae at a temperature of 24.0°C can cause damage to embryos, such as malformation of the body as well as anomalies in the circulatory system.

Co-infection of Liburna oophaga sp. nov. and Ikanecator primus on cuttlefish (Sepia pharaonis) eggs and the effectiveness of peracetic acid as a treatment

The cuttlefish Sepia pharaonis species complex is emerging as a promising set of organisms for research in neuroscience, the behavioral sciences, and commercial aquaculture. At the same time, information about pathogens and diseases that could affect cuttlefish cultivation in intensive aquaculture settings remains limited. Our study has identified two species of parasite, the protozoan Liburna oophaga sp. nov. and the metazoan Ikanecator primus, that co-infect cuttlefish eggs, increasing mortality and reducing hatching rates. L. oophaga sp. nov. is reported here for the first time to enhance mortality during the incubation period by inducing deformity in cuttlefish eggs. We investigated the application of peracetic acid to parasite elimination during cuttlefish egg incubation. When cuttlefish eggs were treated with a peracetic acid containing product (PAA-product); 35 mg/L PAA + 15 mg/L H2O2, L. oophaga on the surfaces of the eggs were eliminated within 10 min. PAA-product; 70 mg/L PAA + 30 mg/L H2O2 was required to achieve the same effect for I. primus. Immersion treatment with PAA-product at 70 mg/L PAA + 30 mg/L H2O2 reduced parasitic load and improved survival of cuttlefish embryos and hatchling size, demonstrating that PAA product can inhibit and control parasitic co-infections in cephalopod culture.

Effects of Different Photoperiods during Incubation on Post-Hatch Broiler Performance and Stress Response.

This study evaluated the subsequent effect of photoperiods during incubation on post-hatch growth and stress response of commercial broiler chickens. A total of 875 Ross 308 broiler breeder (48 weeks of age) eggs were hatched using different durations (0, 4, 8, 12, 16, 20, and 24 h a day) of dichromatic light [green and red (495 to 750 nm); 2700 K; 250 lux; SUNJIE; China] throughout the whole period of incubation. A total of 50 0-day-old hatched straight run broiler chicks from each photoperiod during incubation were used to evaluate subsequent growth performance (feed intake, body weight, and feed conversion ratio); stress parameters (physical asymmetry, tonic immobility, and vocalization,); welfare traits (feather score and gait score); carcass traits (live weight, dressed weight, carcass yield, liver weight, gizzard weight, heart weight, abdominal fat weight, breast weight, and leg weight); and serum chemistry (globulin, total protein, cholesterol, glucose, and uric acid). There were no influences of photoperiod during incubation on post-hatch growth, stress parameters, welfare, and carcass traits. Heart yield was higher in birds incubated under 20 h light than in those from the 16 h light group. Incubation under different lighting durations also altered blood biochemical profile but did not influence serum globulin and cholesterol levels. It was concluded that under experimental conditions, incubation of broiler eggs under different lighting durations did not impact subsequent post-hatch performance (21-35 d).

Smart Egg Incubator Based on IoT and AI Technology for Modern Poultry Farming

The productivity of egg hatching in the poultry industry is often hindered by conventional methods, resulting in low hatch rates and slow production. This study introduces the UHTP (Universitas Hang Tuah Pekanbaru) Smart Egg Incubator, which incorporates Internet of Things (IoT) and Artificial Intelligence (AI) technologies, specifically the Mamdani Fuzzy Logic Algorithm, to enhance egg hatchability. The incubator features a 100-egg capacity, automatic temperature and humidity control, cooling systems, and real-time monitoring via mobile devices. It also includes a camera for movement detection, capturing images of hatching eggs, and sending notifications to users. The automatic egg-turning mechanism ensures even temperature distribution. Experimental results show that the incubator maintains optimal temperatures between 37.7°C and 38.8°C, with successful hatching observed on the 19th day. The fuzzy logic AI system effectively manages environmental changes, ensuring a stable hatching process by dynamically adjusting the conditions within the incubator. The user-friendly interface and remote monitoring capabilities provide convenience and efficiency for poultry farmers. This innovative design significantly improves hatch rates and supports the economic productivity of chicken farming, offering practical solutions for modern poultry farming. The integration of this AI technology can lead to higher profitability and sustainability in poultry farming, addressing common challenges such as inconsistent environmental conditions and labor-intensive processes, thus contributing to the advancement of agricultural practices

The Effects of Rearing Systems on Incubation, Egg Production and Quality Traits in Pharaoh Quails

This study was conducted to determine the effect of rearing quails in different rearing systems on egg production, egg quality characteristics, and incubation results. The 360 quails were distributed equally to 3 different rearing groups (cage, enriched cage, and floor) in a male:female mixed at the age of 3 weeks. The eggs were individually weighed and recorded one by one daily (5487 eggs) for 3 months. To determine egg quality and incubation characteristics, 750 eggs were broken, and 3284 eggs were incubated, respectively. The results showed that female quail in the floor group have lower body weight at 6 weeks old (177.19 g), and they reached sexual maturity (age of first egg laying) later (65.36 day, P&lt;0.01), The lowest egg production (61.14%) occurred in the floor group during the 3-month egg production period (P&lt;0.05). The lowest average egg weight (9.07 g) was determined in the floor group (P&lt;0.05). It was determined that the eggs of quails raised in the enriched group had a rounder shape index because they have larger widths (P&lt;0.01). While the highest average yolk height (11.24 mm) was determined in the enriched cage group (P&lt;0.01), the highest averages of albumen length (72.41 mm) and lowest averages of yolk index (48.43%) were determined in the cage group (P&lt;0.01). The lowest average values (113.17) in Haugh unit were detected in the floor group (P&lt;0.05). The highest fertility rate (98.44%) was in Floor♂:Cage♀, the highest hatchability of fertile egg rate (94.67%) was obtained from Enriched♂:Cage♀, and the highest hatchability (89.10%) was obtained from Floor♂:Cage♀ pairing (P&lt;0.05). The lowest fertility rate (88.00%) was obtained from the Enriched♂:Floor♀, the lowest hatchability of fertile egg rate (86.01%) was obtained from the Enriched♂:Enriched♀, and the lowest hatchability (75.62%) was obtained from the Enriched♂: Enriched♀ groups. As a result, it has been revealed that the effect of various rearing systems is different on egg production, egg quality traits, and hatching results in quails. Thus, it has been shown that different programs at the rearing period to be applied to the male and female quails can achieve better incubation results and reproductive success.

Within the optimal thermal range, temperature fluctuations with similar means have little effect on offspring phenotypes: A comparison of two approaches that simulate natural nest conditions

Temperature influences nearly every aspect of organismal function. Because aspects of global change such as urbanization and climate change influence temperature, researchers must consider how altering thermal regimes will impact biodiversity across the planet. To do so, they often measure temperature in natural and/or human-modified habitats, replicate those temperatures in laboratory experiments to understand organismal responses, and make predictions under models of future change. Consequently, accurately representing temperature in the laboratory is an important concern, yet few studies have assessed the consequences of simulating thermal conditions in different ways. We used nest temperatures for two urban-dwelling, invasive lizards (Anolis sagrei and A. cristatellus) to create two egg incubation treatments in the laboratory. Like most studies of thermal developmental plasticity, we created daily repeating thermal fluctuations; however, we used different methods to create temperature treatments that differed in the magnitude and breadth of thermal cycles, and then evaluated the effects of these different approaches on embryo development and hatchling phenotypes. Additionally, we measured embryo heart rate, a proxy for metabolism, across temperature to understand the immediate effects of treatments. We found that treatments had minimal effect on phenotypes likely because temperatures were within the optimal thermal range for each species and were similar in mean temperature. We conclude that slight differences in thermal treatments may be unimportant so long as temperatures are within a range appropriate for development, and we make several recommendations for future studies of developmental plasticity.

Manufacturing and Feasibility Test of Duck Egg Incubator Machine with Automatic System for Small Industrial Scale

Manufacturing and Feasibility Test of Duck Egg Incubator Machine with Automatic System for Small Industrial Scale

Reproduction and Follow-up of Embryonic Development of Achatina fulica

Although Achatina fulica is hermaphrodite, the fertilization process in this type of snail occurs internally and in conjunction, and the mechanism of reproduction is to place the eggs in groups in a hole and then cover them with dirt. The stages of embryonic development from laying the eggs until the hatching process took ten days and after hatching. A small individual similar to the parents emerges. The criterion for embryonic development in this study focused on the noticeable increase in the size of the fetus with the progression of time or the age of the fetus during the egg incubation period.

Impact of Different Food Sources on the Developmental Biology and Host Preferences of the Red Flour Beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

An experiment conducted at the seed center laboratory at Tamil Nadu Agricultural University during June 2022 evaluated the host preferences and developmental biology of the red flour beetle (Tribolium castaneum) across three food sources: broken rice with rice flour, broken wheat with wheat flour, and tapioca flour. Beetle development was observed in ventilated containers under controlled conditions (28-30°C, 65% relative humidity) with 25 beetles per container. Significant differences in beetle survival and development. Wheat flour was the most favourable host, with 304 live adults, followed by broken wheat (145 live adults. Rice flour supported 20 adults and 11 larvae, indicating moderate suitability. Whole rice grains and tapioca flour were the least effective, with only dead adults and few larvae. Despite host quality variations, the developmental stages (egg incubation: 4-7 days, larval: 65-70 days, pupal: 6-9 days) were consistent across food sources. Wheat flour is the most supportive environment for T. castaneum development.

Influence of Parental Age on Reproductive Potential and Embryogenesis in the Pepper Weevil, Anthonomus eugenii (Cano) (Col.: Curculionidae).

The pepper weevil (Anthonomus eugenii Cano) is a devastating pest that inflicts severe damage to pepper crops, leading to substantial economic losses. This study investigated the impact of aging on the reproductive success of the pepper weevil. Pepper weevil-infested fruit were harvested from pepper fields and subsequently transferred into an insect cage to facilitate the emergence of adults. The emerged adults were housed in separate cages and allowed to mature until they reached specified ages: 10 days old (young), 20 days old (middle-aged), and 30 days old (old) individuals. Eggs laid by each age group were carefully collected and incubated under controlled laboratory conditions (28 ± 1.5 °C). Several reproductive variables including the number of eggs laid, the percentage of hatched eggs, and the egg incubation period were recorded for each age group. Embryonic development was also monitored daily using a VHX digital microscope at a magnification of 200×. Differences in developmental stages such as the blastoderm, germ band, gastrulation, segmentation, and appendage formation were observed, and the time span of every stage was recorded. The results show that the 10-day-old weevils laid the most eggs and had the highest hatching rate and the shortest developmental time. The 30-day-old weevils laid the fewest eggs and had the lowest hatching rate and longest developmental time. Thus, the pepper weevil age significantly influenced the fecundity, length of time for each embryonic development stage, hatching rate, and incubation period, and should be considered when studying the reproductive biology of this pest insect. This first report of the effect of aging on the reproductive potential of the pepper weevil should enable pepper growers to adopt cultural practices aimed at reducing the pepper weevil populations, thereby helping to protect their crop from this important pest.

Blue petrel electrocardiograms measured through a dummy egg reveal a slow heart rate during egg incubation

BackgroundSeabirds like penguins and petrels, living in Antarctic and sub-Antarctic regions, often feed hundreds or even thousands of kilometers away from the islands where they breed. They therefore adapted to endure prolonged fasting during egg incubation, enabling their partner to undertake foraging trips that can last up to two weeks. Aside from accumulating and consuming fat reserves, it is unclear whether seabirds have developed further adaptations to extended fasting periods. This lack of knowledge is in part due to their remote nesting location and their extreme sensitivity to manipulation. To overcome this lack of knowledge, we developed a non-invasive device to record the heart rate (HR) of burrow-nesting blue petrels (Halobaena caerulea) during egg incubation. For that, we encapsulated a small-size logger in a dummy egg to record electrocardiograms (ECGs) through the featherless incubation patch of the birds.ResultsThe blue petrels’ HR (208 ± 15 beats per min [bpm]; n = 6) that we recorded during egg incubation was slower than the HR predicted by two different allometric functions regressing HR against body mass (242 and 250 bpm). Blue petrels’ HR also presented cyclical variation correlated to respiration, resembling the physiological Respiratory Sinus Arrhythmia (RSA) described in humans and other species, and that is mainly modulated by the vagal nerve. Moreover, the basal HR of incubating blue petrels increased about every minute during egg movements that presumably reflect egg turning, important for embryo survival and development. During these events, blue petrels’ HR increased up to a maximum of 296 ± 27 bpm for 18 ± 2 s (n = 6). We estimated that those egg movements increased energy expenditure (EE) by 8.4 ± 1.3%, which is approximately 10 times less than the energy increase induced by the disturbance linked with the removal of the dummy egg at the end of the experiment. Interestingly, we noticed that the beginning of HR increase preceded egg movements by 4.3 ± 0.9 s (n = 6), as if birds needed to gradually increase their metabolism to achieve the following action. As well, blue petrels needed 9.1 ± 1.3 s (n = 6) to recover basal levels of HR after the end of egg movements.ConclusionWe recorded for the first time ECGs, HR and RSA in blue petrels in a completely non-invasive way. This allowed us to observe (1) slow basal HR during egg incubation, which could save energy for prolonged fasting and (2) temporal HR increase, possibly necessary to reposition the egg for proper embryonic development.

Optimization of process parameters for specific pathogen-free chicken embryonic fibroblast cultivation for yellow fever vaccine production

The yellow fever (YF) vaccine is usually produced with egg-based methods, which has limitations, including potential adverse effects and low production yields. Alternatively, producing the vaccine using Vero cells or HEK 293 cells can overcome some of these issues, but these methods are significantly more expensive. In the current study, the YF vaccine candidate 17DD virus was produced in primary chicken embryo fibroblast (CEF) cells. The primary CEF cells isolation from eggs was optimized through a two-step process. In the first step, the important parameters that contribute to the development of the egg embryo, such as egg position, relative humidity (RH), and incubation time are optimized. In second step, primary CEF release parameters namely; trypsin volume and incubation temperature are optimized. Both steps were optimized using statistical methods. Further, the seeding cell density of isolated CEF was also optimized. It was observed that 5 x 104 cells/cm2 gave the highest virus titer of 3.89 million PFU/ml. The 17DD yields achieved in primary CEFs are much higher than egg-based production and it is an economically viable method.

Experience of reproduction of pike (Esox lucius Linnaeus, 1758) using the factory method

The article is devoted to the conducted experience of reproduction of the common pike (Esox lucius Linnaeus, 1758) in the conditions of industrial fish farming. Pike is an important object of aquaculture, used for biomelioration of reservoirs and for amateur fishing. The purpose of this work was to obtain pike larvae by the factory method with a different method of incubation of eggs. To obtain sexual products, pike producers were selected, after bonification they were landed in pools on a direct-flow system. Eggs from females were obtained by pumping, into enameled containers separately for each individual, sperm from males was obtained by slaughtering. After fertilization, the eggs were de-glued and placed in a Weiss apparatus for incubation, a total of 23.75 million pieces of eggs were obtained, the average fertility of females was 25 thousand eggs, the percentage of fertilization was 70%. To conduct the experiment, the eggs were divided into two parts, the group was left for incubation in Weiss devices. Group II at the 22nd stage of development, the “pigmented eye stage”, was placed on frames with a mosquito net of a smaller diameter measuring 0.5 by 0.5 m, with a side height of 1.5 cm in the ICA-2 pools. In the group I at the 24th stage of eggs development, hatching occurred, the survival rate of the larva was 27.3%, in the group II, hatching was 40.8%. At the stage before the transition to active nutrition, the larvae were collected in polyethylene transport bags with oxygen and released into a natural reservoir. Transportation was carried out at 12 degrees, at 2000 pcs/l.