Layer Rate Research Articles

Effects of different rapeseed varieties on egg production performance, egg quality, hormone levels, follicle development, and thyroid function in hens

This study was to evaluate the effects of rapeseed (Brassica napus L.) from China with different content of glucosinolate (Gls) and erucic acid (EA) on laying hens. A total of 600 laying hens at 33 wk of age were randomly divided into 5 treatments containing a control diet and 4 diets with 11.5% rapeseed. The 11.5% rapeseed diets varied in Gls and EA levels: 1) Deyou no. 6 (DY6) with Gls at 22.67 μmol/g and EA at 0.7%, 2) Mianbangyou no. 1 (MB1) with Gls at 43.23 μmol/g and EA at 3.5%, 3) Deyou no. 5 (DY5) with Gls at 74.66 μmol/g and EA at 16.20%, 4) Xiheyou no. 3 (XH3) with Gls at 132.83 μmol/g and EA at 44.60%. Each group had eight replicates and each replicate had 15 hens. The trial lasted for 12 wk with 4 wk withdrawal. From 1 to 8 wk of the trial, 11.5% rapeseed reduced average daily feed intake (ADFI) compared to the control group (P = 0.002), and egg-laying rate of XH3 rapeseed was lower than that of DY6 rapeseed (P = 0.006), and egg weight of MB1, DY5, and XH3 rapeseed were lower than that of the control group (P < 0.01). Egg mass was reduced by 11.5% rapeseed (P = 0.004) and egg mass of XH3 and DY5 rapeseed were lower than that of DY6 rapeseed (P < 0.01). Feed conversion ratio (FCR) of 11.5% rapeseed was higher than that the control group and FCR is higher in XH3 rapeseed than in DY6 rapeseed from 1 to 8 wk (P < 0.01). At wk 8, the lightness value of eggshell color of XH3 rapeseed was significantly lower than that of the control and DY5 rapeseed (P = 0.012). Xiheyou no. 3 rapeseed had a higher redness value of eggshell color than the control and MB1 and DY5 rapeseed (P = 0.008). Albumen height of DY5 rapeseed was lower than that of the control group at wk 8 (P = 0.012). Mianbangyou no. 1 and DY5 rapeseed decreased Haugh unit at wk 4 and 8, respectively (P = 0.011, P = 0.024). Serum E2 content was decreased by 11.5% rapeseed (P = 0.003). Thyroid index increased as the Gls and EA content increased (P = 0.008). The smallest hierarchical follicle numbers of XH3 and MB1 rapeseed were lower than that of the control group (P = 0.009). After 4 wk withdrawal, the egg weight, egg mass, and FCR did not recover (P = 0.011, P = 0.033, P = 0.024, respectively). In conclusion, 11.5% rapeseed decreased egg production performance which might be caused by decreasing hormone levels, and high Gls and EA rapeseed had a lower performance than low Gls and EA rapeseed.

Supplementing pigeon grit with acidifier improves metabolism and the reproductive performance of breeding pigeons as well as the development of growth performance of squabs

ABSTRACT 1. This study evaluated the effectiveness of different types of acidifiers on reproductive performance, body weight loss and plasma biochemical indices of breeding pigeons as well as on growth performance, carcass characteristics, meat quality and plasma biochemical indices of squabs. 2. In a 45 d trial, 144 pairs of European white Mimas pigeons were selected and randomly divided into three experimental groups. Three groups of pigeons were fed plain pigeon grit (NC), pigeon grit supplemented with 5% single acidifier (SAG) and pigeon grit supplemented with 5% combined acidifiers (CAG). 3. Supplementing with SAG and CAG significantly increased the weight gain in male pigeons from 1-12 d of incubation. However, SAG and CAG had no significant effect on the feed intake of breeding pigeons during incubation, but significantly increased total feed intake of breeding pigeons during the lactation period. Breeder pigeons fed SAG and CAG had significantly higher egg-laying rate at 40 d. In addition, feeding SAG and CAG significantly increased growth rate and slaughter weight of squabs, but SAG reduced the diameter of pectoral muscle fibres. Biochemical indices showed that feeding SAG and CAG improved metabolism and increased the liver function of breeder pigeons and squabs. 4. In conclusion, supplementing pigeon grit with acidifiers increased feed intake of breeding pigeons during lactation, protected liver function, enhanced reproductive performance and promoted the growth and development of squabs.

Effects of Different Photoperiods on the Transcriptome of the Ovary and Small White Follicles in Zhedong White Geese.

Photoperiod can regulate the broodiness of geese and thus increase their egg-laying rate. The laying performance of geese is mainly determined by ovary and follicle development. To understand the effect of photoperiod on the ovary and small white follicles, sixteen 220-day-old healthy female Zhedong white geese were randomly divided into two groups for long photoperiods (15L:9D) and short photoperiods (9L:15D). The geese were euthanized after two months of feeding, and their ovaries and follicles were collected for transcriptome sequencing. RNA-seq analysis identified 187 and 448 differentially expressed genes in ovaries and small white follicles of different photoperiod groups, respectively. A long photoperiod promotes high expression of SPP1, C6, MZB1, GP1BA, and FCGBP genes in the ovaries, and increases the expression of SPP1, ANGPTL5, ALPL, ZP1, and CHRNA4 genes in small white follicles. Functional enrichment analysis showed that photoperiod could affect respiratory system development, smooth muscle cell proliferation in ovaries, and extracellular matrix-related function in small white follicles. WGCNA revealed 31 gene modules, of which 2 were significantly associated with ovarian weight and 17 with the number of small white follicles. Our results provide a better understanding of the molecular regulation in the photoperiod affecting goose reproduction.

PSXIII-13 Evaluation of physiological functions and performance in laying hens in different housing systems

Abstract Egg production faces many challenges of economics, disease control and animal welfare concerns. Therefore, investigation of physiological characteristics in laying hens should be required for further discussion on such issues from a scientific point of view. In this study, we evaluated physiological functions and production parameters of hens raised in three different housing systems, conventional battery cage (CC), enriched cage (EC) and aviary system (AV). Lohmann Selected Leghorn Lite laying hens (n = 251) were used. At first, all the pullets were housed in CC. Then, a telemetric transmitter was implanted to randomly selected 18 hens on d 171 after birth to record electrocardiograms (ECGs), heart rate (HR), body temperature (BT) and locomotor activity (LA). Heart rate variability (HRV), which was analyzed using ECG, has been established as a suitable method for investigating autonomic nervous functions, and to assess stress and well-being of housing systems. On d 200 after birth, some of the hens were randomly selected and transferred to EC or AV (CC; n = 88, EC; n = 72, AV; n = 91), including hens implanted a transmitter (6 hens in each group). All parameters at 10 d before and 1 wk after the group division were compared. Egg laying rate (ELR), feed conversion ratio (FCR) and shell deformation were evaluated for egg production parameters. Hens were basically housed under the same management condition, and a constant light-dark cycle (light-on from 0300 to 1930 h). Feeding was conducted during light-phase, and water was supplied ad libitum. Statistical significance was defined as P &amp;lt; 0.05. Comparing the physiological parameter, HR during dark-phase and LA during light-phase after transferred to EC or AV were greater than those in CC. However, there was no significant difference in HR during light-phase or LA during dark-phase between CC and the other two groups. The high frequency (HF) power of HRV, which reflects parasympathetic nervous function, was high during the dark-phase (7.59 ± 1.56) and low during the light-phase (6.04 ± 0.78) in CC. This diurnal variation disappeared in EC or AV because the HF power during the dark-phase decreased. As for production, ELR, FCR and shell deformation were decreased after moved to AV, which were not found in other two groups after the group division. This study was conducted to clarify the effects of housing systems on the physiological functions and productivity of laying hens, and these results suggest that CC might provide hens with parasympathetic dominance with greater quality of rest in dark-phase, and AV causes the reduction of egg production. However, we cannot completely rule out the possibility that these results are influenced by movement to a different housing system. Therefore, further analysis should be performed to assess the relations between physiological functions, management and egg production.

Results and Discussion of Dengue Model with Temperature Effects in Interval Environment

We have investigated a dengue model with temperature effects under interval uncertainty in this work. This study observed the Aedes aegypti temperature-dependent entomological parameters that affect dengue illness transmission dynamics in Taiwan's subtropical zone. A vector-host transmission model was used to examine how temperature fluctuations influence the development of pre-adult mosquitoes, their egg-laying rates, adult mortality, and the incubation rate of viruses within them. This study showed that although estimations of entomological parameters were positively correlated with slow temperature rises, no such correlation was detected with mosquito mortality or maturation rates, underscoring the slow rate of maturation of pre-adult mosquitoes. The findings suggest that the dynamic modeling of vector-host interactions is significantly influenced by temperature. Additionally, our modeling indicates that a temperature range of about 32°C is ideal for dengue transmission. In the future, control measure modeling and cost-effectiveness assessments may benefit from these insights.

Wolbachia-infected pharaoh ant colonies have higher egg production, metabolic rate and worker survival.

Wolbachia is a widespread maternally transmitted endosymbiotic bacteria with diverse phenotypic effects on its insect hosts, ranging from parasitic to mutualistic. Wolbachia commonly infects social insects, where it faces unique challenges associated with its host's caste-based reproductive division of labor and colony living. Here, we dissect the benefits and costs of Wolbachia infection on life-history traits of the invasive pharaoh ant, Monomorium pharaonis, which are relatively short lived and show natural variation in Wolbachia infection status between colonies. We quantified the effects of Wolbachia infection on the lifespan of queen and worker castes, the egg-laying rate of queens across queen lifespan, and the metabolic rates of whole colonies and colony members. Infected queens laid more eggs than uninfected queens but had similar metabolic rates and lifespans. Interestingly, infected workers outlived uninfected workers. At the colony level, infected colonies were more productive as a consequence of increased queen egg-laying rates and worker longevity, and infected colonies had higher metabolic rates during peak colony productivity. While some effects of infection, such as elevated colony-level metabolic rates, may be detrimental in more stressful natural conditions, we did not find any costs of infection under relatively benign laboratory conditions. Overall, our study emphasizes that Wolbachia infection can have beneficial effects on ant colony growth and worker survival in at least some environments.

Complex dynamical behaviors of a honeybee-mite model in parameter plane

The honeybee has a significant impact on ecosystem stability, biodiversity conservation, and pollinating crops. However, during the past few years, there has been a sharp reduction in both the honeybee population and their colonies. It has been found that the parasitic mite Varroa destructor is responsible for the decline in honeybee colonies around the world, which in turn immensely affects the economic growth of a country. To investigate how the dynamics of a system is influenced by the growth of honeybees and the parasitism of mites, we study a nonlinear honeybee-mite population model in a discrete-time setup. We observe that an increase in the value of the queen’s egg-laying rate drives the system towards chaos. However, chaos can be controlled as well if the parasite attachment effect is increased. The intrinsic dynamical properties of the proposed system are investigated with the simultaneous variation of the queen’s egg-laying rate and the mite’s parasite attachment effect by constructing several largest Lyapunov exponent and isoperiodic diagrams. The investigation reveals the existence of several periodic structures in the quasiperiodic and chaotic regimes of the parameter plane, including Arnold tongues, saddle area, spring area, connected shrimp-shaped structure, and connected saddle area. We also find the appearance of a novel ‘jellyfish’-shaped periodic structure. One of the most fascinating findings of this study is the appearance of Arnold tongues along the inner boundary region of another Arnold tongue. In addition, this work also reveals different types of multistability, e.g., the coexistence of two, three, and even four attractors. What is more interesting is that the current analysis unveils the coexistence of five attractors as well, more specifically, four different periodic attractors coexist with the trivial fixed point attractor, which is quite rare in ecological systems. The structures of the basins of these coexisting attractors are either smooth or very complex in nature. Furthermore, the present study also discloses the fact that variation in the initial condition of the system can significantly change the appearance of the periodic structures in the parameter plane.

Comparison of genomic prediction accuracy using different models for egg production traits in Taiwan country chicken

In local chickens targeted for niche markets, genotyping costs are relatively high due to the small population size and diverse breeding goals. The single-step genomic best linear unbiased prediction (ssGBLUP) model, which combines pedigree and genomic information, has been introduced to increase the accuracy of genomic estimated breeding value (GEBV). Therefore, this model may be more beneficial than the genomic BLUP (GBLUP) model for genomic selection in local chickens. Additionally, the single-step genome-wide association study (ssGWAS) can be used to extend the ssGBLUP model results to animals with available phenotypic information but without genotypic data. In this study, we compared the accuracy of (G)EBVs using the pedigree-based BLUP (PBLUP), GBLUP, and ssGBLUP models. Moreover, we conducted single-SNP GWAS (SNP-GWAS), GBLUP-GWAS, and ssGWAS methods to identify genes associated with egg production traits in the NCHU-G101 chicken to understand the feasibility of using genomic selection in a small population. The average prediction accuracy of (G)EBV for egg production traits using the PBLUP, GBLUP, and ssGBLUP models is 0.536, 0.531, and 0.555, respectively. In total, 22 suggestive- and 5% Bonferroni genome-wide significant-level SNPs for total egg number (EN), average laying rate (LR), average clutch length, and total clutch number are detected using 3 GWAS methods. These SNPs are mapped onto Gallus gallus chromosomes (GGA) 4, 6, 10, 18, and 25 in NCHU-G101 chicken. Furthermore, through SNP-GWAS and ssGWAS methods, we identify 2 genes on GGA4 associated with EN and LR: ENSGALG00000023172 and PPARGC1A. In conclusion, the ssGBLUP model demonstrates superior prediction accuracy, performing on average 3.41% than the PBLUP model. The implications of our gene results may guide future selection strategies for Taiwan Country chickens. Our results highlight the applicability of the ssGBLUP model for egg production traits selection in a small population, specifically NCHU-G101 chicken in Taiwan.

Genome-Wide Association Analysis and Genetic Parameters for Egg Production Traits in Peking Ducks.

Egg production traits are crucial in the poultry industry, including age at first egg (AFE), egg number (EN) at different stages, and laying rate (LR). Ducks exhibit higher egg production capacity than other poultry species, but the genetic mechanisms are still poorly understood. In this study, we collected egg-laying data of 618 Peking ducks from 22 to 66 weeks of age and genotyped them by whole-genome resequencing. Genetic parameters were calculated based on SNPs, and a genome-wide association study (GWAS) was performed for these traits. The SNP-based heritability of egg production traits ranged from 0.09 to 0.54. The GWAS identified nine significant SNP loci associated with AFE and egg number from 22 to 66 weeks. These loci showed that the corresponding alleles were positively correlated with a decrease in the traits. Moreover, three potential candidate genes (ENSAPLG00020011445, ENSAPLG00020012564, TMEM260) were identified. Functional enrichment analyses suggest that specific immune responses may have a critical impact on egg production capacity by influencing ovarian function and oocyte maturation processes. In conclusion, this study deepens the understanding of egg-laying genetics in Peking duck and provides a sound theoretical basis for future genetic improvement and genomic selection strategies in poultry.

Mathematical analysis of transmission dynamics of Acute Bee Paralysis Virus within a hive

In this paper, a mechanistic model of Acute Bee Paralysis Virus (ABPV) transmission is designed and analyzed. The qualitative behavior of honeybee-pathogen and honeybee-pathogen-mite interactions sub-models revealed the existence of backward bifurcation. It is shown that whenever the survivability of a newly hatched egg is guaranteed, both the disease-free and endemic equilibria of the sub-models are globally asymptotically stable. Sensitivity and uncertainty analyses have shown that egg-laying, viral ingestion and deposition rates are the most influential parameters that drive ABPV infection. Suggesting that intervention strategies that focus on how to manage these rates are required for effective control. The combination of disinfection and fumigation of hives, using optimal control analysis, is shown to be the most effective strategy for controlling the spread of ABPV infection. In addition, disinfection alone is found to be the most cost-effective strategy. Finally, an extended model that incorporates mite migration and parasitism is formulated and simulated. The results have shown that mite migration weakens the colony and spacing hives to the farthest distance a forager can reach strengthen the colony. It is also shown that parasitism contributes towards colony collapse, however, fumigation strategy reduces honeybee mortality due to parasitism.

Honey bee colony behavior and ontogeny are adversely affected when exposed to a pesticide-contaminated environment.

Honey bees exhibit age polyethism and thus have a predictable sequence of behaviors they express through developmental time. Numerous laboratory studies show exposure to pesticides may impair critical honey bee behaviors (brood care, foraging, egg-laying, etc.) that adversely affect colony productivity and survival. There are fewer studies that examine the impacts of pesticides in natural field settings, especially given the challenges of implementing treatment groups and controlling variables. This study helps address the need for impact studies on pollinators under field conditions to assess the consequences of chemical overuse and dependency in agricultural and urban landscapes. To assess the impact of systemic pesticides in a natural field setting on worker bee behavioral development, observation hives were established to monitor changes in behaviors of similarly aged workers and sister queens within 2 experimental groups: (i) colonies located near point-source systemic pesticide pollution (pesticide contaminated treatment), and (ii) colonies embedded within a typical Midwestern US agricultural environment (control). In this study, worker bees in the contaminated environment exhibited important and biologically significant behavioral differences and accelerated onset of hive tasks (i.e., precocious behavioral development) compared to similarly aged bees at the control site. Queen locomotion was largely unaffected; however, the egg-laying rate was reduced in queens at the contaminated (treated) site. These results show that environmental pesticide exposure can disrupt colony function and adversely affect worker bee behavioral maturation, leading to reduced worker longevity and decreased colony efficiency.

Hypergravity Impact on Fertility of Apis mellifera carnica Queens – Case Study

The launch is considered the most stressful rocket flight stage due to the hypergravity occurrences. The possibility of using honey bees (Apis mellifera) as the extraterrestrial pollinator depends on their ability to reproduce correctly after experiencing hypergravity. The described study aims to verify the impact of a launching rocket’s acceleration on honey bee queen’s egg-laying behavior. Four artificially inseminated A. mellifera carnica queens were placed in the Human Training Centrifuge and given to the acceleration pattern of the launching Soyuz rocket. Next, the data on the number of food stores, eggs, larvae, and worker and drone pupae were collected from the test and control hives using the modified Liebefeld method. The pilot study results imply that accelerated queen’s egg-laying behavior may change twofold: limiting or maximizing the number of laid eggs, with the control queen egg-laying rate remaining stable for all samples. The number of drone pupae is greater for the test sample colonies, with its earlier appearance in the hive. No impact on overwintering success was observed. Authors indicate limitations of the results and a need to continue the study to verify the occurrence of anomalies potentially related to the examined factor.

Effects of Moringa oleifera Leaf Meal on Local Guinea Fowl Breeder Hens Performance, Egg Quality, and Blood Parameters

Breeding local guinea fowl has the potential to address protein malnutrition and alleviate poverty in West African countries. The current study aimed to examine the effects of incorporating Moringa oleifera leaf meal into the diet on hematology and biochemical parameters as well as the productive performance of local guinea fowl breeders in Togo. Thus, 512 local guinea fowls (22 weeks of age with an average weight of 1176.7 ± 2.9 g), comprising 384 females and 128 males, were examined for 31 weeks. The fowls were randomly assigned to four dietary groups, namely M0, M1, M2, and M3 containing 0%, 0.5%, 1%, and 1.5% of Moringa oleifera leaf meal in diets, respectively. Each group had 4 replicates of 32 fowls. During the study, feed intake, body weight, egg-laying rate, and feed conversion ratio were weekly recorded. Blood samples for hematology and biochemical analysis were taken from 12 females (3/replicate) at 34 and 50 weeks of age. Eggs were collected for the quality evaluation. Results showed that feed intake was comparable across all groups during the rearing period (23 to 33 weeks of age). However, it significantly decreased in fowls of the M2 and M3 during the laying period (34 to 50 weeks of age). The live weight of fowls in M3 was significantly higher than other groups before the laying period. The egg production, yolk ratio, and shell ratio of the birds in the M1 were like that of M0 and higher than that of M2 and M3. The feed conversion ratio was not significantly different between groups during the laying period. However, the albumen ratio and haugh unit were improved by feeding Moringa leaves especially at level 1.5%. The level of white blood cells and lymphocytes decreased by feeding the Moringa leaves at 1%. Neutrophils and platelet levels were comparable across groups. Total proteins, albumin, and transaminases increased in Moringa groups (M1, M2, M3), especially in M3. It was concluded that the use of Moringa oleifera leaves at 0.5% improved egg-laying performance in local guinea fowl. Moreover, 1% and 1.5% of incorporation improved the quality of eggs. Keywords: Blood parameter, Breeder, Guinea fowl, Egg quality, Moringa oleifera

Two-stage LEDs illuminated plastic bag photobioreactor for production of astaxanthin from Haematococcus pluvialis and manipulated egg yolk pigment by astaxanthin

Astaxanthin is one of the most significant secondary metabolites with high price because of its high antioxidant activity. It can be used in commercial applications, including the nutraceutical, pharmaceutical, and aquaculture Haematococcus pluvialis contains the richest natural source for astaxanthin, so it has gained a lot of attention for commercial astaxanthin production. It is suggested that H. pluvialis can produce astaxanthin through a two-stage process that involves growing biomass under optimal conditions and then subjecting this biomass to stress conditions to cause astaxanthin accumulation. In this study, we used a two-stage LED-illuminated technique to produce high level of astaxanthin in a plastic bag photobioreactor. Plastic bag PBRs have received increased attention in recent years due to low cost and simplicity of controlling the culture. The results demonstrated that the two-stage procedure on plastic bags using shifting red-blue LED had the ability to produce high quality astaxanthin at a low production cost. The highest dry biomass and astaxanthin content were 2.53 g L-1 and 5.09%, respectively. The yolk color and egg-laying rate of hens improved when their diets were supplemented with H. pluvialis biomass. Hens fed with 0.2%, 0.5%, and 1% biomass rose by 8% (63.81%), 16% (68.57%), and 17% (69.52%), respectively, as compared to controls (59.05%). ® 2023 Journal of Science and Technology - NTTU

Colony size of amazonian stingless bees and its assessment through intrinsic parameters

Stingless bees live in populous colonies that vary in size from a few hundred individuals to tens of thousands, although information on actual colony size is limited. The objectives of this study were to determine the colony size of five Amazonian stingless bee species (Melipona flavolineata, Melipona fasciculata, Scaptotrigona aff. postica, Frieseomelitta longipes, and Plebeia minima), and to identify biological parameters that covary with colony size. The number of brood cells, adult bees, and food stocks were counted under laboratory conditions, alongside field assessments of egg-laying rate and external activity of adult workers. To identify covariates of colony size, the number of adult bees was regressed against the number of brood cells, egg-laying rate, external activity of adult workers, and food stocks, and the best candidate models were ranked using the Akaike Information Criterion. Mean (±s.d.) adult populations were: in M. flavolineata, 1046 ± 185; in M. fasciculata, 593 ± 300; in S. aff. postica, 7404 ± 1391; in F. longipes, 2425 ± 1000 and in P. minima, 405 ± 254. Thus, we showed that the external activity is the biological parameter, after the number of brood cells, that presents the best relationship with the number of adult bees, which can be easily evaluated in the field. Determining colony sizes using easily measurable biological parameters are important steps to understanding stingless bee’s life histories, ecology, and evolution, and to ease their keeping and utilization for pollination.

Functional characteristics of Dicer genes in Plutella xylostella.

Dicer is an endonuclease that belongs to the RNase III family and can specifically recognize and cleave double-stranded RNA (dsRNA). In most insects, there are two Dicer genes, Dicer-1 (Dcr-1) and Dicer-2 (Dcr-2), which are involved in the micro-RNA and small-interfering RNA pathways in many species, respectively. The function of Dicer in Plutella xylostella remains unknown. The full-length open reading frames of P. xylostella Dicer-1 (PxDcr-1) and Dicer-2 (PxDcr-2) were cloned and sequenced. Dcr-1andDcr-2 proteins shared similar structural domains with the Dicer-Partner Binding Domain (Dicer-PBD) and the double-strand RNA binding domain (dsRBD) present only in Dcr-1. The phylogenetic trees showed that lepidopteran Dcr-1s or Dcr-2s clustered in one branch, with PxDcr-1 in the basal position and PxDcr-2 closest to Plodia interpunctella Dicer. Two homozygous knockout lines, ΔPxDcr-1 and ΔPxDcr-2, were obtained by using the CRISPR-Cas9 technique. The ΔPxDcr-1 strain exhibited a high mortality rate, a low eclosion rate, a low egg-laying rate, a low hatching rate, and a shriveled ovariole without mature eggs. The ΔPxDcr-2 strain showed no significant difference from the wild-type in terms of survival, development and reproduction, but the RNA interference (RNAi) efficiency caused by dsRNA was significantly reduced. These findings demonstrate the involvement of PxDcr-1 in the development and reproduction of P. xylostella, specifically in the formation of ovarioles and eggs, and PxDcr-2 is indispensable for RNAi. These findings shed light on the function of Dcr-1 and Dcr-2 in Lepidoptera. © 2023 Society of Chemical Industry.

Transgenerational Effects of Maternal Zinc Deficiency on Zinc Transporters in Drosophila melanogaster.

Maternal nutrition, including the availability of micronutrients such as zinc, influences the health of the offspring. Using Drosophila melanogaster, we studied the impact of zinc deficiency on development and reproduction, as well as the effects of maternal zinc status on the offspring's expression of zinc transporters across F1 to F3 generations. Zinc deficiency was induced by adding N,N,N',N'-Tetrakis (2-pyridylmethyl)-ethylenediamine (TPEN) to the diet on which the eggs representing the F0 generation flies were laid. Then, virgin F0 females were mated with control males to produce F1, and subsequently thereafter to generate F2 and F3. Offspring from F1 to F3 were analyzed for body zinc status and zinc transporter mRNA levels. We found that zinc deficiency significantly (p < 0.05) impaired the development of flies, as evidenced by a reduced eclosion rate of zinc-deficient flies. Similarly, zinc deficiency significantly (p < 0.05) reduced the egg-laying rate in F0 flies, highlighting its impact on reproductive functions. Also, zinc levels were consistently lower in the F0 and persisted in subsequent generations for both male and female offspring, indicating transgenerational alterations in zinc status. Furthermore, gene expression analysis revealed significant (p < 0.05) variations in the mRNA levels of dZip42C.1, dZnT63C, dZip71B, and dZnT35C genes across different generations and between male and female offspring. These findings indicate gender-specific dynamics of gene expression in response to zinc deficiency, suggesting potential regulatory mechanisms involved in maintaining zinc homeostasis. Our study emphasizes the detrimental effects of zinc deficiency on development and reproduction in Drosophila and highlights potential implications for offspring and human health.

Two-stage LEDs illuminated plastic bag photobioreactor for production of astaxanthin from Haematococcus pluvialis and manipulated egg yolk pigment by astaxanthin

Astaxanthin is one of the most significant secondary metabolites with high price because of its high antioxidant activity. It can be used in commercial applications, including the nutraceutical, pharmaceutical, and aquaculture Haematococcus pluvialis contains the richest natural source for astaxanthin, so it has gained a lot of attention for commercial astaxanthin production. It is suggested that H. pluvialis can produce astaxanthin through a two-stage process that involves growing biomass under optimal conditions and then subjecting this biomass to stress conditions to cause astaxanthin accumulation. In this study, we used a two-stage LED-illuminated technique to produce high level of astaxanthin in a plastic bag photobioreactor. Plastic bag PBRs have received increased attention in recent years due to low cost and simplicity of controlling the culture. The results demonstrated that the two-stage procedure on plastic bags using shifting red-blue LED had the ability to produce high quality astaxanthin at a low production cost. The highest dry biomass and astaxanthin content were 2.53 g L-1 and 5.09%, respectively. The yolk color and egg-laying rate of hens improved when their diets were supplemented with H. pluvialis biomass. Hens fed with 0.2%, 0.5%, and 1% biomass rose by 8% (63.81%), 16% (68.57%), and 17% (69.52%), respectively, as compared to controls (59.05%).&#x0D; ® 2023 Journal of Science and Technology - NTTU

Nest Construction Costs Bald Eagles Time But not Breeding Success or Productivity

ABSTRACT Constructing nests costs birds time and energy and may influence breeding success and productivity. The precise nature and extent of these costs is understudied, particularly among raptor species. We used linear and generalized linear mixed models to examine the time and reproductive costs of nest construction to Bald Eagles (Haliaeetus leucocephalus) in New Jersey, USA, from 2009 to 2021. To differentiate nest construction costs from the influence of experience, we separately analyzed the breeding performance and phenology of new pairs constructing nests, established pairs constructing nests, and established pairs reusing nests. We also considered the influence of weather, year, and ecoregion. New territorial pairs building nests were generally less successful and productive than established pairs building or reusing nests. However, these trends were largely attributable to a greater egg-laying rate among established pairs. Nest building pairs, new and established, were generally delayed in egg laying, hatching, and nestling fledging compared to established pairs reusing nests; new pairs were notably more delayed than established pairs building nests. Territorial pairs in the Atlantic Coastal Pine Barrens were less successful and productive than pairs in other ecoregions. Higher precipitation around the egg laying period was predictive of lower nest success and productivity rates but did not appear to affect phenology. Higher temperatures around this period also lowered these rates, with the further effect of advancing phenology. In New Jersey, climate change appears to be advancing breeding phenology and could constrain productivity by century’s end, though we anticipate that density dependence will regulate and lower Bald Eagle breeding performance prior to this period. Breeding success and productivity rates, as well as the effects of year in our models, indicate that New Jersey’s breeding Bald Eagle population is still healthy and growing. Overall, our results indicate that nest construction imposes minor temporal costs on Bald Eagles but does not meaningfully affect their breeding success or productivity, which may help inform management of Bald Eagle nests and populations.

Orychophragmus violaceus and/or chicory forage affects performance, egg quality, sensory evaluation and antioxidative properties in native laying hens

Orychophragmus violaceus (OV) and chicory (Cichorium intybus L., CC) can be used as fresh or dry forage for animals. To determine whether OV and/or CC have beneficial effects on performance and egg quality, a total of 1212 28-wk-old Beijing You Chicken (BYC) laying hens with similar performance were randomly allocated to 4 groups with 3 replicate pens per group, and 101 birds per pen. The birds were fed a basal diet (control), the basal diet + OV (3.507 kg/d/pen), the basal diet + CC (2.525 kg/d/pen), and the basal diet + OV + CC (OVC, 1.7535 kg/d/pen OV + 1.2625 kg/d/pen CC) for 3 wks after one wk of adaptation. The results showed that egg-laying rate was not affected by OV, CC and OVC (p > 0.05), but weekly average egg mass was significantly increased by OV and CC (p < 0.05). The feed egg ratio in the CC group (2.82) was significantly lower than that in the other three groups (p < 0.05). The eggshell thickness (EST), albumen height (AH) and Haugh unit (HU) were decreased by OV and CC (p < 0.05); while yolk color (YC) was increased in the CC and OVC groups (p < 0.05). Egg grade was decreased by OV (p < 0.05). Sensory evaluation showed that there was a trend for increased YC in OV, CC and OVC (p = 0.089). Serum total protein was significantly lower in OV group than those in the control and CC group (p < 0.05); serum albumin content was significantly decreased in OV, CC and OVC groups (p = 0.006). Serum glutathione peroxidase activity in CC and OVC groups was significantly higher than that in the control group (p < 0.05). In conclusion, the present study suggests that CC had a better effect on the performance of the native laying hens than OV. The OV and CC affected egg quality, while YC was increased in CC and OVC groups. The OVC improved YC and serum antioxidative properties of native laying hens without affecting the performance.