Egg Concentrations Research Articles

Effect of diet composition and temperature on the gastric evacuation rate of European sardine: implication for egg predation estimates

Cannibalism and intraguild predation of fish eggs are frequently observed for small and medium pelagic fish and can be an important cause of natural mortality. The European sardine Sardina pilchardus is the major predator of pelagic fish eggs in Atlantic Iberian waters. Estimates of egg mortality due to predation rely on a number of parameters that are frequently unknown for most species, such as gastric evacuation rate (GER) and feeding periodicity, and rates obtained for other fish species are generally used. These assumptions can severely affect egg mortality estimates. We conducted laboratory experiments to estimate the GER of European sardine that were fed diets composed of different proportions of fish eggs and other food types, such as Artemia franciscana nauplii, Brachionus plicatilis and microalgae, at different temperatures experienced by sardine in the wild (15, 17 and 21°C). Temperature, predator size and sex did not influence the gastric rates. Prey type significantly affected the GER of sardines, with slower evacuation when offered diets containing a higher concentration of fish eggs rather than microalgae, rotifers and Artemia nauplii. Fish eggs are more nutritionally rich compared to microalgae, rotifers and Artemia nauplii, and therefore more difficult to digest. GERs obtained here for S. pilchardus were similar to those obtained for Sardinops sagax in South Africa. This study provides important information that allows for improving estimates of daily feeding rates and egg mortality by predation, thus increasing our understanding of small pelagic fish population dynamics.

Bleaching reduces reproduction in the giant clam Tridacna gigas

Bleaching or the expulsion of the photosynthetic symbiont Symbiodiniaceae (‘zooxanthellae’) caused by the increase in seawater temperatures causes massive mortalities in giant clams. After a bleaching disturbance, population recovery is heavily dependent on reproduction and recruitment success. However, how bleaching directly affects the reproductive performance of giant clams is, to date, unknown. Here, we examined the direct impacts of bleaching on the reproduction of the giant clam Tridacna gigas between 2020 and 2021 in the Philippines. A continuous 6 mo monitoring of egg concentration, egg stage, egg size, recovery, and survival in prolonged bleached (moderate or severe) and non-bleached hatchery-bred T. gigas maintained in the wild was conducted. The probability of producing eggs and the proportion of intact eggs (developing and mature) were highest in healthy giant clams, followed by moderately bleached giant clams, and lowest in severely bleached giant clams in which >50% individuals had empty gonads. The oocyte mean diameter was similar among giant clams, regardless of degree of bleaching. Only 5 severely bleached giant clams showed partial color recovery, whereas 2 healthy and 12 severely bleached giant clams died. This study shows that apart from the lethal effects of severe bleaching, the reproductive processes of surviving bleached T. gigas such as gametogenesis and egg production can be also negatively affected. Results suggest that the increasing frequency and intensity of bleaching due to thermal stress can lower the reproductive potential of giant clams and likely other zooxanthellate organisms, resulting in reduced recruitment and population decline.

Dioxin transfer simulation from feed to animal tissues and risk assessment

Dioxins might be introduced into the food chain through a direct or an indirect pathway. The main source of human exposure to dioxins is food of animal origin, whereas feeds are the main route of exposure of farmed animals to dioxins and polychlorinated biphenyls. The aim of the study was to simulate dioxin passage from feed to tissues on farm animals using transfer models, and, in addition, to assess the risk to consumers of food of animal origin. From over 700 feed samples analyzed over the course of 9 years (2013–2021), those exceeding the maximum permissible levels set down in Commission Regulation No 277/2012/EU were selected. These samples being derived from real cases of dioxin contamination made it possible to present the most realistic picture of the effects these feed materials could have had if they had entered the food chain. Three species of animals were selected (laying hens, dairy cattle and slaughter pigs), for which feed materials with dioxin contents exceeding the maximum permissible level were selected in accordance with the nutritional recommendations. The calculated PCDD/PCDF concentrations in chicken eggs, cow's milk and pork were above the maximum permissible level in most cases.

Factors influencing mercury levels in Leach's storm-petrels at northwest Atlantic colonies

Mercury (Hg) is a globally distributed heavy metal, with negative effects on wildlife. Its most toxic form, methylmercury (MeHg), predominates in aquatic systems. Levels of MeHg in marine predators can vary widely among individuals and populations. Leach's storm-petrels (Hydrobates leucorhous) have elevated levels of Hg but the role of Hg in storm-petrel population declines is unknown. In this study, we used egg and blood samples to study variation in Hg exposure among several northwest Atlantic colonies during breeding seasons, thereby evaluating relative toxicity risk within and among colonies. Total mercury (THg) concentrations were higher with increasing colony latitude, and were more pronounced in blood than in eggs. THg concentrations in blood were mostly associated with low toxicity risk in birds from the southern colonies and moderate risks in birds from the northern colonies; however, those values did not affect hatching or fledging success. THg concentrations in both eggs and blood were positively correlated with δ34S, emphasizing the role of sulfate-reducing bacteria in methylation of THg acquired through marine food webs, which is consistent with enriched δ34S profiles. By associating tracking data from foraging trips with THg from blood, we determined that blood THg levels were higher when storm-petrel's intensive search locations were over deeper waters. We conclude that spatial variation in THg concentrations in Leach's storm-petrels is attributable to differences in ocean depth at foraging locations, both at individual and colony levels. Differences in diet among colonies observed previously are the most likely cause for observed blood THg differences. As one of the few pelagic seabird species breeding in Atlantic Canada, with limited overlap in core foraging areas among colonies, Leach's storm-petrels can be used as biomonitors for less sampled offshore pelagic regions. The global trend in Hg emissions combined with legacy levels warrant continued monitoring for toxicity effects in seabirds.

Urbanization and maternal hormone transfer: Endocrine and morphological phenotypes across ontogenetic stages

The phenotypes observed in urban and rural environments are often distinct; however, it remains unclear how these novel urban phenotypes arise. Hormone-mediated maternal effects likely play a key role in shaping developmental trajectories of offspring in different environments. Thus, we measured corticosterone (Cort) and testosterone (T) concentrations in eggs across the laying sequence in addition to Cort concentrations in nestling and adult female house wrens (Troglodytes aedon) at one urban and one rural site. We found that egg T concentrations were not different between birds from urban and rural sites. However, across all life stages (egg, nestling, and adult female), Cort concentrations were higher at the urban site. Additionally, urban nestling Cort concentrations, but not rural, correlated with fine-scale urban density scores. Furthermore, rural egg volume increased over the laying sequence, but urban egg volume leveled off mid-sequence, suggesting either that urban mothers are resource limited or that they are employing a different brood development strategy than rural mothers. Our study is one of the first to show that egg hormone concentrations differ in an urban environment with differences persisting in chick development and adult life stages. We suggest that maternal endocrine programing may shape offspring phenotypes in urban environments and are an overlooked yet important aspect underlying mechanisms of urban evolution.

Trace element composition of Gallus gallus domesticus eggs and health risks associated with their consumption in Port Harcourt, Nigeria

Using a multivariate approach, this study investigated the trace element composition and concentration in Gallus gallus domesticus eggs. A total of 51 freshly laid Gallus gallus domesticus egg samples were randomly obtained and analyzed for trace elements using a flame atomic absorption spectrophotometer. The results showed that the levels of zinc, lead, nickel, cobalt, manganese, iron and copper were in the range of 2.16 ± 0.03 – 7.43 ± 0.98 mg/L, <0.001 ± 0.00 – 9.86 ± 1.01 mg/L, <0.001 ± 0.00 – 1.44 ± 0.30 mg/L, <0.001 ± 0.00 – 0.35 ± 0.01 mg/L, <0.001 ± 0.00 – 0.76 ± 0.04 mg/L, 2.93 ± 1.01 – 11.52 ± 1.54 mg/L and 0.03 ± 0.05 – 0.967 ± 0.06 mg/L, respectively. However, mercury, chromium, and cadmium were not detected in all the samples. This suggests the absence of toxicity risk due to these non-essential elements in the eggs, especially when they are consumed. Moreover, the target hazard quotient and total target hazard quotient of the eggs were less than 1, thereby suggesting no probable harm, as well as non-carcinogenic hazards respectively.

Determination of the relative potencies of brominated dioxins for risk assessment in aquatic environments using the early-life stage of Japanese medaka

World Health Organization toxic equivalency factors (WHO-TEFs) are recommended for risk management of brominated dioxins in aquatic environments because limited information is available on their toxicity to fish. To validate this approach, we obtained the relative potencies of polybrominated dibenzo-p-dioxins and polybrominated dibenzofurans and mixed-halogenated furans (PXDF, X = Cl/Br) against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) based on their toxicity to the early-life stage of Japanese medaka (Oryzias latipes). 2,3,7,8-substituted brominated dibenzofurans caused typical dioxin exposure effects, such as blue-sac disease. The TCDD-relative potency factors (REPs) of test substances were calculated based on the concentrations in water and eggs that caused 20% lethality on day 28 post-fertilization, and were in the order of: 2-chloro-3,7,8-tribromodibenzofuran (REPwater 3.3, REPegg 4.6) > 2,3,7,8-tetrabromodibenzofuran (0.85, 0.92) > 2,3,4,7,8-pentabromodibenzofuran (0.053, 0.55) > 1,2,3,7,8-pentabromodibenzofuran (0.0091, 0.19). The transfer rate from water to eggs was lower for pentabrominated furans than tetrabrominated congeners, and was expected to decrease with the log Kow of the test substance. Although the REPegg value can be used to compare the toxicity potential of brominated dioxins, REPwater may be more suitable for environmental risk assessment because the uptake potential of these compounds from water should be considered. This study is the first to report higher toxicity of a PXDF congener compared with TCDD in vivo, further investigations of the toxicity of mixed-halogenated dioxins and environmental behavior are necessary for environmental risk assessment.

The Efficacy of Methyl Alcohol Extracts of Albizzia lebbeck (L.) Benth Seeds , Melia azedarach L. Fruits and their mixture in Comparisom with Actellic Insecticide on Eggs and adult emergence of cowpea weevil Callosobruchus maculatus (Fab.)(Coleoptera:Bruc

This study has carried out in laboratory to reveal the efficacy of methyl alcohol extract of Albizzia lebbeck (L.) Benth seeds and Melia azedarach L. fruits , in addition to their mixtures ( 1:1) , which is compared with the insecticide Actellic 50% EC., on Eggs and adult emergence of cowpea weevil , Callosobruchus maculatus (Fab.) under laboratory conditions of 30+ 2 C. and 60+5% relative humidity.Results have shown that there is significant differences in percentages of egg hatching of 1 , 2 and 3 days old which is treated with concentrations of 2,4,6,8,10% of methyl alcohol extract of Albizzia lebbeck seeds and Melia azedarach fruits ; the concentrations of 1,2 and 3% of the mixture of both and the concentrations of 0.05 , 0.075 % of the insecticide. There is a converse relationship between egg hatching and concentrations . Eggs of 1 day old are more resistant than other ages , since the highest egg hatching , 87.5% and 72.2% for Albizzia lebbeck seeds and Melia azedarach fruits respectively occur with 2% concentration compared with control which is 98.00 and 96.00% for both of them respectively. While Adult emergence has reached 80.36 and 75.6 % compared with control which is 94.00 and 100.00% for both of them respectively for the same age and concentration. The lowest hatching and emergence percentages are 52.5 and 69.79% of Albizzia lebbeck seeds extract at 6% concentration and 17.5 , 72.22 % of Melia azedarach fruits extracts at 8% concentration . No egg hatching occurs at 8% concentration of Albizzia lebbeck and 10% of Melia azedarach extracts for all ages .The highest egg hatching of 1day eggs old and adult emergence is 45.49 and 87.50 % at 1% concentration for mixed extraction compared with control which is 100.0 and 96.67 % . The lowest egg hatching is 5.00 % at 3% concentration and the lowest adult emergence 25.0% at 2% concentration compared with control which is 100.0 and 93.33% for eggs of 3 days old ; and there is no adult emerged at 3% for all ages . The highest egg hatching of 55% occurs at 0.05 concentration of actellic for 1 day old compared with control treatment which is 100.0% , and there is no hatching for the other ages and concentrations.

Bioaccumulation of PCDD/Fs and PCBs in free-range hens: Congener fingerprints and biotransfer factors

The bioaccumulation of lipophilic environmental contaminants in farm animals is an important issue to control and prevent human exposure to toxic pollutants. Free-range hens were used as a model to assess the transfer and the bioaccumulation of PCDD/Fs, DL-PCBs and NDL-PCBs from the soil to eggs in an area in the Campania region particularly affected by pollution, the “Land of Fires”. We determined the following ranges of concentrations in eggs: 0.90–5.51 pg WHO-TEQ g−1 fat for PCDD/Fs; 1.63–4.24 pg WHO-TEQ g−1 fat for DL-PCBs; 2.77–9.75 pg WHO-TEQ g−1 fat for the sum of PCDD/Fs and DL-PCBs and 12.53–30.94 ng g−1 fat for NDL-PCBs. Higher contamination levels were observed in the eggs from free-range hens, compared to those of the control group, that is hens raised indoors; this indicates that soil remains a major source of contamination. Livers showed low levels of contamination for both outdoor and indoor reared hens. Biotransfer factors (BTFs) were calculated for each of the 35 PCDD/F and PCB congeners analysed. The BTFs highlighted that the transfer and bioaccumulation depend on chlorination degree and substitution pattern, in particular they increase with increasing chlorination degree up to the hexa-chlorinated congeners and then decrease. An exception to these finding was observed for 2,3,7,8 TCDD and 2,3,7,8 TCDF, which showed very high BTFs. These results demonstrate the importance of promoting studies on the environmental contaminants bioaccumulation as they provide an effective support for the risk assessment and management of exposure to toxic chemicals.

A new method for determining PFASs by UHPLC-HRMS (Q-Orbitrap): Application to PFAS analysis of organic and conventional eggs sold in Italy

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous environmental pollutants with the ability to uptake to food and feed. Among food, fish, fruits and eggs are considered as major contributors to human dietary exposure. A new method was developed and validated for the simultaneous determination of 18 PFASs in eggs using isotope dilution followed by ultrahigh performance liquid chromatography coupled to high resolution mass spectrometry. The analysis of 132 samples (organic, barn and caged eggs) was performed. Levels were always close to the detection limits and no significant difference emerged among the 3 groups. The highest PFAS concentration in eggs was used to estimate the dietary exposure of different Italian population groups. As expected, children were more highly exposed than adults due to lower body weight. This data suggests that the recent tolerable weekly intake of 4.4 ng kg-1b.w. could be exceeded when the cumulative intake arising from other food products is considered.

Home-produced eggs: An important human exposure pathway of perfluoroalkylated substances (PFAS)

Humans are generally exposed to per- and polyfluoroalkyl substances (PFAS) through their diet. Whilst plenty of data are available on commercial food products, little information exists on the contribution of self-cultivated food, such as home-produced eggs (HPE), to the dietary PFAS intake in humans. The prevalence of 17 legacy and emerging PFAS in HPE (N = 70) from free-ranging laying hens was examined at 35 private gardens, situated within a 10 km radius from a fluorochemical plant in Antwerp (Belgium). Potential influences from housing conditions (feed type and number of individuals) and age of the chickens on the egg concentrations was examined, and possible human health risks were evaluated. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were detected in all samples. PFOS was the dominant compound and concentrations (range: 0.13–241 ng/g wet weight) steeply decreased with distance from the fluorochemical plant, while there was no clear distance trend for other PFAS. Laying hens receiving an obligate diet of kitchen leftovers, exhibited higher PFOS and PFOA concentrations in their eggs than hens feeding only on commercial food, suggesting that garden produce may be a relevant exposure pathway to both chickens and humans. The age of laying hens affected egg PFAS concentrations, with younger hens exhibiting significantly higher egg PFOA concentrations. Based on a modest human consumption scenario of two eggs per week, the European health guideline was exceeded in ≥67% of the locations for all age classes, both nearby and further away (till 10 km) from the plant site. These results indicate that PFAS exposure via HPE causes potential human health risks. Extensive analysis in other self-cultivated food items on a larger spatial scale is highly recommended, taking into account potential factors that may affect PFAS bioavailability to garden produce.

Nutritional compositions, pathogenic microorganisms and heavy metal concentration in green turtle eggs (Chelonia mydas) from Terengganu and Sabah, Malaysia

A total of 60 green turtle eggs were obtained from sampling sites in Terengganu and Sabah, Malaysia. Isolation and identification of bacteria from these eggs resulted in 12 genera of Gram-negative bacteria with 12 different species. The most frequently isolated bacteria wereSalmonella(30.9%) andProteus(23.7%). The rest of the microorganisms wereAeromonas, Escherichia, Citrobacter, Enterobacter, Klebsiella, Morganella, Pseudomonas, Shigella, SerratiaandPhotobacterium.A slight difference in total crude protein content was recorded in the samples from Terengganu and Sabah, at 16.3% Dry matter (DM) and 15.8% DM, respectively. Meanwhile, the crude fat content found in the samples from Terengganu was 9.88% DM and 7.79% DM from Sabah. In this study, α-linolenic acid, C18:3 n-3 (Terengganu: 16.87% DM) and linoleic acid, C18:2 n-6 (Sabah: 15.19% DM) were the most prevalent fatty acids in both samples. The green turtle egg samples from Terengganu showed higher value of total saturated fatty acid, total C18:3 n-3 and C18:2 n-6 and total polyunsaturated fatty acids as compared to green turtle eggs from Sabah. The results also revealed that majority of the essential amino acids (EAA) recorded in samples from both sampling sites was lysine (9.67% DM), with higher value recorded in green turtle egg from Terengganu. However, there were no significant differences (p>0.05) in the nutritional compositions, fatty acid contents and amino acid compositions of the samples between the two sampling sites. Meanwhile, statistical analysis showed significant differences in heavy metal concentrations between the two sampling sites for all the six heavy metals detected in this study (Hg, Cd, Pb, Mn, Zn and Cu). The ranking of heavy metals concentration in turtle eggs from both sampling sites, in decreasing order is as follows: Zn > Cu > Mn > Pb > Cd > Hg. Overall, these results reveal the contents and contaminations of a green turtle egg, which may raise concern on public health risks. Findings from this study will also be beneficial for the future conservation of green turtle population when the consumption of their eggs should be stopped.

Pilot study on the effect of secondary copper smelters on polychlorinated naphthalene contamination in surrounding agricultural areas

Polychlorinated naphthalenes (PCNs) are dioxin-like persistent organic pollutants that are primarily produced unintentionally during industrial thermal processes. These compounds are harmful to the environment and human health. This study investigated the occurrences of all 75 PCN congeners in agricultural areas near secondary copper smelters in China. The PCN concentrations in aquatic foods, eggs, crops, sediments and soils within 10 km of these smelters were higher than those in samples collected 20–30 km away from such facilities. In contrast, the PCN concentrations in compound animal feed samples collected at different distances from the secondary copper smelters were comparable to one another. Similar PCN homologue patterns were found in crop, egg, feed and soil samples collected at different distances from the smelters but the homologue profiles of PCNs in aquatic food and sediment samples collected from different distances varied. Lower chlorinated naphthalenes were the predominant homologues in most samples. The contamination of farm animals and crops with PCNs might result from the emission of these compounds from such sources into the surrounding environment. However, the health risks associated with human exposure to PCNs through food consumption are low for both distances (<10 km and 20–30 km) from secondary copper smelters.

Egg Hatchability and Egg Thiamine Concentrations in Lake Trout from the Northern Refuge of Lake Michigan

AbstractThe Northern Refuge of Lake Michigan was established in 1985 under the auspices of the Great Lakes Fishery Commission as part of an intensely managed effort to restore a self‐sustaining Lake Trout Salvelinus namaycush population to the lake. Despite the stocking of millions of Lake Trout into the refuge and survival of these stocked fish to adulthood, signs of natural recruitment by Lake Trout in the refuge have been very sparse. To ascertain whether low egg viability or poor fry survival could be limiting natural recruitment by Lake Trout in the refuge, hatching rates of eggs taken from Lake Trout caught in the Northern Refuge during October 2019 were determined in the laboratory. Moreover, survival rates of the hatched‐out fry were determined along with the thiamine concentrations in the fry. In addition, thiamine concentrations in eggs of ovulating Lake Trout caught in the Northern Refuge during 2019–2021 were determined. Egg hatching rate in the laboratory averaged 93%. Survival rate of Lake Trout fry up to 5 weeks after hatching averaged 97%. Mean (SE) thiamine concentrations in eggs of Lake Trout caught in 2019, 2020, and 2021 were 19.1 (3.6), 5.9 (1.3), and 6.2 (0.4) nmol/g, respectively; these levels are well above the threshold concentration of 2.3 nmol/g, above which the likelihood of experiencing mortality due to thiamine deficiency complex (TDC) is low. Thiamine concentrations in the Lake Trout fry at the end of the laboratory experiment averaged 11.2 nmol/g, and abnormal behavior in the fry was not observed. We conclude that TDC does not appear to represent a major impediment to Lake Trout rehabilitation in the Northern Refuge at present, although TDC may have contributed to the lack of detectable natural recruitment in the past.

The impact of climate sensitive factors on the exposure to organohalogenated contaminants in an aquatic bird exploiting both marine and freshwater habitats

To assess how climate-sensitive factors may affect the exposure to organochlorines (OCs) and perfluoroalkyl substances (PFASs), we monitored concentrations in eggs of the common goldeneye (Bucephala clangula) over two decades (1999–2019) in central Norway. The goldeneye alternates between marine and freshwater habitats and is sensitive to climate variation, especially due to alterations in ice conditions which may affect feeding conditions. We assessed how biological factors such as diet (stable isotopes δ13C and δ15N), the onset of egg laying, and physical characteristics such as winter climate (North Atlantic Oscillation: NAOw) influenced exposure. We predicted compounds to show different temporal trends depending on whether they were still in production (i.e. some PFASs) or have been banned (i.e. legacy OCs and some PFASs). Therefore, we controlled for potential temporal trends in all analyses. There were declining trends for α- and γ-hexachlorocyclohexane (HCH), oxychlordane, cis-chlordane, cis-nonachlor, p,p′-dichlorodiphenyltrichloroethane (p.p′-DDT) and less persistent polychlorinated biphenyl (PCB) congeners (e.g. PCB101). In contrast, the dominant compounds, such as p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and persistent PCB congeners, were stable, whereas hexachlorobenzene (HCB) increased over time. Most OCs were positively related to δ15N, suggesting higher exposure in birds feeding at upper trophic levels. Chlordanes and HCB were positively associated with δ13C, indicating traces of marine input for these compounds, whereas the relationships to most PCBs were negative. Among PFASs, perfluorooctanesulfonamide (PFOSA) and perfluorohexane sulfonic acid (PFHxS) declined. Most PFASs were positively associated with δ13C, whereas there were no associations with δ15N. Egg laying date was positively associated to perfluoroheptanesulfonic acid (PFHpS), perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), suggesting that some of the PFAS load originated from the wintering locations. Although NAOw had little impact on the exposure to organohalogenated contaminants, factors sensitive to climate change, especially diet, were associated with the exposure to OHCs in goldeneyes.

Lead poisoning of backyard chickens: Implications for urban gardening and food production

Increased interest in backyard food production has drawn attention to the risks associated with urban trace element contamination, in particular lead (Pb) that was used in abundance in Pb-based paints and gasoline. Here we examine the sources, pathways and risks associated with environmental Pb in urban gardens, domestic chickens and their eggs. A suite of other trace element concentrations (including As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn) are reported from the sampled matrices. Sixty-nine domestic chickens from 55 Sydney urban gardens were sampled along with potential sources (feed, soil, water), blood Pb concentrations and corresponding concentrations in eggs. Age of the sampled chickens and house age was also collected. Commercial eggs (n = 9) from free range farms were analysed for comparative purposes. Study outcomes were modelled using the large Australian VegeSafe garden soil database (>20,000 samples) to predict which areas of inner-city Sydney, Melbourne and Brisbane are likely to have soil Pb concentrations unsuitable for keeping backyard chickens. Soil Pb concentrations was a strong predictor of chicken blood and egg Pb (p=<0.00001). Almost 1 in 2 (n = 31/69) chickens had blood Pb levels >20 μg/dL, the level at which adverse effects may be observed. Older homes were correlated with higher chicken blood Pb (p = 0.00002) and egg Pb (p = 0.005), and younger chickens (<12 months old) had greater Pb concentrations, likely due to increased Pb uptake during early life development. Two key findings arose from the study data: (i) in order to retain chicken blood Pb below 20 μg/dL, soil Pb needs to be < 166 mg/kg; (ii) to retain egg Pb < 100 μg/kg (i.e. a food safety benchmark value), soil Pb needs to be < 117 mg/kg. These concentrations are significantly lower than the soil Pb guideline of 300 mg/kg for residential gardens. This research supports the conclusion that a large number of inner-city homes may not be suitable for keeping chickens and that further work regarding production and consumption of domestic food is warranted.

Transfer of Non-Dioxin-Like Polychlorinated Biphenyls (ndl-PCBs) from Feed and Soil into Hen Eggs.

Understanding the transfer of non-dioxin-like polychlorinated biphenyls (ndl-PCBs) into foods of animal origin is crucial for human health risk assessment. In two experiments, we investigated the transfer of ndl-PCBs from contaminated feed and soil into eggs and meat of laying hens. The transfer from the feed was investigated with 30 laying hens. The treated hens were divided into two groups fed a contaminated diet (12.8 μg/kg sum of indicator ndl-PCBs; 88% dry matter (DM)) for 28 and 63 days, respectively, and then experienced a depuration period of 100 days with control feed. The transfer from soil was investigated with 72 laying hens kept in three separate outdoor pens (with three levels of ndl-PCB soil contamination) for 168 days. In both experiments, eggs were collected and analyzed for ndl-PCBs. In the second experiment, animals (n = 3 at the beginning, n = 6 per group after 42, 84, and 168 days) were slaughtered to determine ndl-PCBs in meat (breast muscle tissue) fat. The transfer of ndl-PCB from both feed and soil was clearly measurable and concentrations in eggs quickly exceeded maximum levels. Clear differences between individual congeners were observed. In particular, the low-chlorinated ndl-PCBs 52 and 101 are hardly found in eggs, despite their relatively high concentration in feed and soil. PCBs 138, 153, and 180, on the other hand, were found in large proportions in eggs and meat.

Impact of spawn concentrations on Atlantic herring (Clupea harengus) egg survival in Baltic Sea inshore spawning areas

Fish species classified as demersal substrate spawners attach their eggs on macrophytes or hard substratum. As a result of consecutive events of egg deposition and successive waves of spawning adults, the formation of multiple egg layers on spawning substrate was already observed for demersal spawning fish species, such as the Atlantic herring (Clupea harengus, Linnaeus 1758). However, empirical information on the effects of egg concentration on herring egg survival are scarce. Hypothesizing that high egg concentration has a negative effect on herring egg survival, we experimentally investigated egg mortalities in artificially spawned egg clusters of 1–10 vertical layers. Moreover, potential effects of egg packing density (loose and dense) in one single layer set-up were investigated. We found decreasing herring egg survival in clusters of increasing egg layers. Although egg mortality was lowest in surface layers, a layerwise analysis did not reveal a stepwise increase of egg mortality from outermost to innermost eggs. Furthermore, egg mortality in surface layers significantly increased with increasing egg layer number underneath, indicating that the extent of layering is affecting egg mortality also in surface layers. This implies a reproductive disadvantage not only for eggs being spawned in the beginning of consecutive spawning events but also for latest spawned eggs. However, different egg packing densities in single layer spawn did neither influence the fertilization success nor mortality of herring eggs. Increased thickness of egg layers may result from the ongoing reduction and fragmentation of coastal vegetation due to eutrophication and coastal modifications. Our results indicate that such multiple egg layer deposition has the potential to negatively impact hatching success in demersal spawning fish species, such as the herring.

Immune Response (Serum Globulin) in BALB/c Mice after Hookworm Egg Protein Immunization as the Initial Stage of Developing Laboratory Diagnostics: An In Vivo Approach

BACKGROUND: Hookworm infestation is still high and requires practical laboratory diagnosis with high sensitivity and specificity. Meanwhile, there are several limitations associated with the existing method; hence, a new method is essentially needed. Furthermore, the principle of immunological reactions needs to be developed by identifying the extent of hookworm eggs suspension immune responses. The BALB/c mouse is among the most widely used inbred models used in biomedical research and is particularly utilized in immunology and infectious disease research. AIM: This study aims to determine whether the protein concentration of hookworm eggs stimulates antibodies formation (proteins) in the serum of BALB/c mice. METHODS: This is an experimental study with a post-test only control design approach. Egg protein was isolated by removing the contents using a mini drill to immunize BALB/c mice, while the antibody response was observed by spectrophotometer and agglutination methods. RESULTS: The Chi-square and Post hoc statistical tests showed a significance p ≤ 0.001 indicating a relationship between hookworm egg protein and agglutination results. The higher the antibody level, the more visible the agglutination and vice versa. CONCLUSION: These results are expected to form a basis for developing more practical and efficient diagnostic methods based on antigen-antibody reactions.

Egg fatty acid profiles and potential health risk from defatted insect meal in laying hens’ diets

Insects, a staple feed for wild birds and free ranging poultry, have a relatively high protein quality and are a promising feed for commercial poultry. Replacing soybean meal with insect derived feeds potentially reduces dependency on feed imports, increasing the sustainability of egg production – but only if maintaining or enhancing their nutritional quality. This study investigated egg fatty acid (FA) profiles from replacing soyabean meal with Hermetia illucens (black soldier fly) meal (HIM) for laying hens. A three-week trial with 30 organic Lohman Selected Leghorn hens between 64-74 weeks old was repeated with four flocks at the end of their first laying cycle. In all replicate trials, ten birds were randomly allocated to each of three diets: (1) control with 360 g soybean/kg and no HIM; (2) H12 with 120 g HIM and 156 g soybean/kg; and (3) H24 with 240 g HIM/kg and no soybean. Complete replacement of soya (H24) increased saturated fatty acid (SFA) and monounsaturated fatty acids (MUFA) and decreased total polyunsaturated fatty acids (PUFA), omega-6 (n-6) and omega-3 (n-3) PUFA concentrations in eggs. The intermediate H12 diet (replacing 33% soya) gave similar n-3 and MUFA concentrations to control eggs but significantly increased SFA and reduced total PUFA. However, birds moderated the transfer of high intakes of potentially damaging C12:0 and C14:0 into eggs and although differences in eggs were highly significant and great (relative to very low levels in control eggs) concentrations were substantially lower than in insect meal itself and some commonly consumed foods.