Egg Production Rate Research Articles

Wolbachia strains wMel and wAlbB differentially affect Aedes aegypti traits related to fecundity.

Two Wolbachia strains, wMel and wAlbB, have been transinfected into Aedes aegypti mosquitoes for population replacement with the aim of reducing dengue transmission. Epidemiological data from various endemic sites suggest a pronounced decrease in dengue transmission after implementing this strategy. In this study, we investigated the impact of the Wolbachia strains wMel and wAlbB on Ae. aegypti fitness in a common genetic background. We found that Ae. aegypti females infected with the wMel strain exhibited several significant differences compared with those infected with the wAlbB strain. Specifically, wMel-infected females laid significantly fewer eggs, ingested a lower amount of blood, had a reduced egg production rate, and exhibited a decreased Wolbachia density at a later age compared with mosquitoes infected with the wAlbB strain. Conversely, the wAlbB strain showed only mild negative effects when compared with Wolbachia-uninfected specimens. These differential effects on Ae. aegypti fitness following infection with either wMel or wAlbB may have important implications for the success of population replacement strategies in invading native Ae. aegypti populations in endemic settings. Further research is needed to better understand the underlying mechanisms responsible for these differences in fitness effects and their potential impact on the long-term efficacy of Wolbachia-based dengue control programs.IMPORTANCEThe transmission of arboviruses such as dengue, Zika, and chikungunya is on the rise globally. Among the most promising strategies to reduce arbovirus burden is the release of one out of two strains of Wolbachia-infected Aedes aegypti: wMel and wAlbB. One critical aspect of whether this approach will succeed involves the fitness cost of either Wolbachia strains on mosquito life history traits. For instance, we found that wMel-infected Ae. aegypti females laid significantly fewer eggs, ingested a lower amount of blood, had a reduced egg production rate, and exhibited a decreased Wolbachia density at a later age compared with mosquitoes infected with the wAlbB strain. Conversely, the wAlbB strain showed only mild negative effects when compared with Wolbachia-uninfected specimens. These differential effects on mosquito fitness following infection with either wMel or wAlbB may have important implications for the success of population replacement strategies in invading native Ae. aegypti populations.

Effects of dietary supplementation of polysaccharide from Agaricus blazei Murr on productive performance, egg quality, blood metabolites, intestinal morphology and microbiota of Korean quail.

This study aimed to investigate the effects of dietary supplementation with Agaricus blazei polysaccharide (ABP) at varying concentrations on the performance, egg quality, blood biochemistry, intestinal morphology, and microflora of quail. The study involved a total of 2,700 Korean quails, which were randomly divided into three groups. The measured variables encompassed productive performance, egg parameters, carcass parameters, serum metabolites, immune response parameters, antioxidative properties, and gut microbiome. The addition of ABP did not have a significant effect on average daily feed intake. However, it was found to increase the average daily egg weight and egg production rate, reduce the feed-egg ratio. There were no significant impacts on egg quality measures such as egg shape index, egg yolk index and color, egg yolk and protein content. However, ABP supplementation significantly increased the Hough unit (p<0.01) and decreased the rate of unqualified eggs (p<0.01). Regarding serum parameters, the inclusion led to an increase in total protein concentration (p<0.05) and a reduction in low-density lipoprotein cholesterol (p<0.05). There were no significant effects observed on immune indicators such as immunoglobulin A (IgA) and IgM. ABP supplementation increased the levels of serum antioxidant indicators, including glutathione peroxidase, total superoxide dismutase (p<0.05), and total antioxidant capacity colorimeter (p<0.05). Furthermore, ABP supplementation significantly elevated the intramuscular fatty acid content in quail meat. Additionally, ABP supplementation demonstrated a significant improvement in the diversity of gut microbiota and induced alterations in the composition of the gut microbiota. The findings of this study indicate that dietary supplementation of ABP enhanced production performance and antioxidant capacity while increasing the levels of polyunsaturated fatty acids in quail muscle.

Effects of Clostridium butyricum on Production Performance and Bone Development of Laying Hens.

Probiotics are safe, inexpensive, and effective feed additives, and Clostridium butyricum (CB) has been reported to regulate bone health in addition to having conventional probiotic effects. The bone health of laying hens is closely related to their production performance. Here, we investigated the effects of CB supplementation on the bone health and performance of laying hens. We added CB to the feed of green-shell laying hens, Luhua laying hens, and Hy-line Brown laying hens and examined changes in body weight, feed intake, egg production performance, and egg quality to determine the impact of CB on production performance. The impact of CB on the bones of laying hens was determined by analyzing the bone index, bone bending strength, bone calcium and phosphorus content, and bone mineral density. The study found that CB had little effect on the body weight and feed intake of laying hens. Feed additions of 108 and 109 CFU/kg CB can significantly increase the tibia index and bone mineral density of four-week-old green-shell laying hens. Feed additions of 107 and 108 CFU/kg CB can significantly increase the average egg weight, eggshell weight, and tibia index of 26-week-old Luhua laying hens, but 107 CFU/kg CB will reduce the egg production rate. Adding 108 CFU/kg CB to feed can significantly increase the average egg weight, eggshell weight, and tibia bending strength of 40-week-old Hy-line Brown laying hens. In summary, adding 108 CFU/kg CB is beneficial to the bone and production health of laying hens.

Production Performance and Profitability of Small-scale Commercial Poultry Farms in Arsi and East-Showa Zones, Central Ethiopia

Poultry farming and the demand for chicken meat and eggs are growing due to their quality protein, essential nutrients, affordable price, and low investment cost. The current study was designed to investigate the productivity and profitability of small-scale commercial poultry enterprises. Data were collected from 221 poultry farms using a semi-structured questionnaire. The results were presented using descriptive statistics. Farm performances were measured by total-factor-productivity (TFP), benefit-cost-ratio (BCR), and net-profit-margin (NPM). The majority of the poultry farm owners were male (69.68%) and married (77.4%). Around 55.2% of poultry farmers aged 31-45 years. Group-owned farms had 4.59 ± 1.77 individual members. On average, a batch of layer chickens was kept for 17.0 ± 3.87 and 18.12 ± 4.25 months on individual and group-owned farms, respectively. Moreover, the mean selling ages of pullet and broiler chickens were 2.55 ± 0.71 and 2.18 ± 0.51 months, respectively. The flock size of layer chickens in sole-proprietor farms (562 ± 724) was significantly lower than in partnership farms (1165 ± 877). The average numbers of produced pullets by sole-proprietorship and partnership farms were 3177 ± 2360 and 3137 ± 1826, while the mean numbers of broilers produced were 2257 ± 1875 and 3269 ± 1669, respectively. The average egg and broiler weights in sole-proprietorship farms were significantly higher compared to group-owned farms. Annual egg production rates in individual and group-owned farms were 76.5% and 70.4%, respectively. The cost of feed, chicken, housing, labor, and medication were the top five production expenditures, while feed cost shares 60.4%. Egg producers had NPM, BCR, and TFP indices of 38.99%, 1.03, and 2.03, respectively, with notable differences by ownership types. The NPM, BCR, and TFP indices for broiler and pullet farms, respectively, were 42.78%, 0.93, and 1.93 for broilers and 35.21%, 0.92, and 1.67 for pullets. The results indicated that poultry firms performed optimally, regardless of ownership type. To further improve the efficiency and profitability of poultry enterprises, farmers need technical, finance, and management skills and input supply chains. Keywords: Broiler, Layer, Poultry, Production, Profitability, Pullet

Effect of Vitamin D3 Enrichment by Ultra Violet Blue (UVB) Radiation and Dietary Zinc Supplementation on Egg Production and Feed Consumption in Layer Birds

Nutritionists have recently been involved in enriching or altering the nutritional profile of poultry products, such as meat and eggs, in relation to increased consumer interest in the nutritional value of foods. Newer technologies like development of designer eggs were exploited beyond their traditional food value. Designer eggs are those that have modified contents from standard egg according to the consumers’ preference or according to current market demand. The present study to evaluate the influence of vitamin D3 enrichment by UVB radiation and dietary zinc supplementation on egg production and feed consumption in layer birds was conducted at Department of Veterinary Physiology, College of Veterinary and Animal Sciences, Mannuthy, for a period of 12 weeks from 01 February 2020 to 01 May 2020. A total of sixty-four laying hens, belonging to crossbred (White Leghorn N strain and Desi) housed in animal house attached to the department were used in the experiment. The treatments of this study included a control diet (according to BIS 2007) fed group (group I), a group with zinc supplementation alone (group II), a group with UVB exposure without zinc supplementation (group III) and a group with both UVB exposure and zinc supplementation (group IV). The four treatments were tested in 28-week-old crossbred hens in a completely randomised experimental design. Each of the experimental treatments had four replicates with four birds with all standard managemental conditions. The statistical analysis showed that egg production was not significantly affected by UVB light exposure and dietary zinc supplementation. However, the effect of UVB exposure and zinc supplementation via feed was highly significant (p≤0.01) for feed consumption. The highest overall mean feed intake (113.18±0.14 g/day) was recorded with those birds exposed to UVB and fed with inorganic zinc. While the lowest value (107.17±0.24 g/day) was recorded in group of birds fed with zinc supplementation in diet without UVB exposure. As a future prospective we can study the egg production rate and feed consumption rate in layer chicken that are intended for different types of designer egg production.

Long-term supplementation of genistein improves immune homeostasis in the aged gut and extends the laying cycle of aged laying hens

Aging is associated with alterations in gut function, including intestinal inflammation, leaky gut, and impaired epithelial regeneration. Rejuvenating the aged gut is imperative to extend the laying cycle of aged laying hens. Genistein is known to have beneficial effects on age-related diseases, but its precise role in homeostasis of the aged gut of laying hens remains to be elucidated. In this study, 160 45-wk-old Hyline Brown laying hens were continuously fed a basal diet or a diet supplemented with 40 mg/kg genistein until they reached 100 wk of age. The results revealed that long-term genistein supplementation led to an improvement in the egg production rate and feed conversion ratio, as well as an increase in egg quality. Moreover, the expression levels of senescence markers, such as β-galactosidase, P16, and P21, were decreased in the gut of genistein-treated aged laying hens. Furthermore, genistein ameliorated gut dysfunctions, such as intestinal inflammation, leaky gut, and impaired epithelial regeneration. Treg cell-derived IL-10 plays a crucial role in the genistein-induced regulation of age-related intestinal inflammation. This study demonstrates that long-term consumption of genistein improves homeostasis in the aged gut and extends the laying cycle of aged laying hens. Moreover, the link between genistein and Treg cells provides a rationale for dietary intervention against age-associated gut dysfunction.

Assessment of four different dietary amino acid profiles recommended for ISA Brown layer hens: A validation study

The current feeding study was designed to validate the two dietary essential amino acid profiles (EAAP) established based on linear broken-line (LBL) and quadratic broken-line (QBL) models, in a previous study, against Evonik (AMINOHen) and breeder recommendations for ISA Brown layers for peak production (PP, 20 to 44 weeks of age), and post peak production (post PP, 44 to 75 weeks of age). The EAAP based on LBL models on average had 19.5% and 26.0% lower digestible AA (Lys, Met + Cys, Thr, Trp, Ile and Val), than the EAAP based on QBL models for PP and post PP, respectively. The EAAP based on AMINOHen and breeder recommendation had lower digestible AA than QBL, and higher EAAP than LBL models for both production phases. At 20 weeks of age, 224 ISA Brown layer hens were weighed and randomly allocated to individual battery cages. Each of the four diets was replicated 8 times with 7 birds per replicate. Egg production was recorded daily, and egg weights were measured at the end of each week. Feed consumption was measured at the end of each period. The egg production rate was not significantly affected by the diets and remained at around 98.0% (PP) and 95.0% (post PP) (P > 0.05). Birds fed diets based on LBL recommendation consistently laid smaller eggs, resulting in a lower egg mass (59.8 vs. 62.0 g egg/hen per day during PP, and 60.3 vs. 63.0 g egg/hen per day during post PP; P < 0.05). Diets had no significant effect on feed intake and body weight (P > 0.05). The highest feed conversion ratio (FCR) during PP (P = 0.067) and post PP (P < 0.05) was recorded for the birds offered diets based on LBL recommendation. In conclusion, all four EAAP tested in this study support an above average egg production rate. However, the EAAP based on LBL models may potentially decrease the input feed cost per kilogram of eggs but are not set to optimise FCR and maximise egg mass.

Effect of egg production dynamics on the functional response of two parasitoids.

Functional response describes the number of hosts attacked by a parasitoid in relation to host densities and plays an important role by connecting behavioral-level processes with community-level processes. Most functional response studies were carried out using simple experimental designs where the insects were confined to a plain and small arena with different host densities during a fixed period of time. With these designs, other factors that might affect the functional response of parasitoids were not analyzed, such as fecundity, age, and experience. We proposed a series of latent-variables Markovian models that comprised an integrated approach of functional response and egg production models to estimate the realized lifetime reproductive success of parasitoids. As a case study, we used the parasitoids Anagyrus cachamai and A. lapachosus (Hymenoptera: Encyrtidae), two candidate agents for neoclassical biocontrol of the Puerto Rican cactus pest mealybug, Hypogeococcus sp. (Hemiptera: Pseudococcidae). The tested species were assessed according to their physiology and prior experience. We estimated the number of mature eggs after emergence, egg production on the first day, egg production rate, the proportion of eggs resorbed, egg resorption threshold, and egg storage capacity. Anagyrus cachamai and A. lapachosus both presented a type III functional response. However, the two parasitoids behaved differently; for A. cachamai, the number of parasitized hosts decreased with female age and depended on the number of mature eggs that were available for oviposition, whereas A. lapachosus host parasitism increased with female age and was modulated by its daily egg load and previous experience. The methodology presented may have large applicability in pest control, invasive species management, and conservation biology, as it has the potential to increase our understanding of the reproductive biology of a wide variety of species, ultimately leading to improved management strategies.

The effect of breeds and rearing system on laying performance and egg quality of local chickens

The study was to identify the reproductive performance of Vietnamese local chickens, named Noi chickens from 36 - 46 weeks of age. The study aimed to determine the effect of breeds and rearing system on laying performance and egg quality of local chickens. The study was a factorial design with 2x2 factors and involved with 120 layers. The first factor was 2 rearing systems (experimental free-range farming system in Tra Vinh province and local free-range farming system in Ben Tre province). The second factor was 2 breeds (egg and broiler purpose). The results showed that egg production rate, laying egg per week were significantly different between breeds and rearing systems (P&lt;0.05) while feed intake was not different. The highest egg production rate recorded at week 44 with 38.42%. For egg quality, yolk diameter, yolk color and yolk index were different breeds and rearing system. It can be recommended that rearing system in Ben Tre province and egg purpose breed was better for egg production and quality.

Laying Performance of Native Chicken (Gallus gallus L.) Fed with Natural Egg Enhancers

Native chickens, inherent to sustainable agriculture, play a crucial role in diverse ecosystems and local economies. Recognizing their significance, this study, conducted at Lagangilang, Abra aimed to evaluate the impact of annatto seed, turmeric, and red-hot pepper as additives on the egg performance of native chickens over four months laid out in a Completely Randomized Design (CRD). Focusing on laying performance in terms of average monthly egg laid, hen house egg production (HDEP), egg mass, egg weight, and mortality and morbidity rate. The research revealed no significant differences in various egg performance parameters, nevertheless, the T3 annatto seed had the highest mean among the treatments next with the commercial egg booster in terms of laid eggs, while unexpectedly contributing to a reduction in mortality and morbidity rates among native chickens. The study suggests that while these additives may not serve as direct egg promoters, they hold promise for improving specific aspects of native chicken eggs, warranting further investigation into their potential health benefits and optimization for market appeal. In terms of return above the feed, stock, and additive costs, utilizing annatto seed and turmeric as additives is 4-13%. Hence, a comprehensive understanding of these implications is vital for informed decision-making when considering additives and enhancers in native chicken production. Though all egg enhancers are acceptable, the prevailing price of the additives to be used should be considered.

Research Note: Effect of different photoperiodic programs from rearing period on the reproductive performance and hormone secretion of White King pigeons

The photoperiod is an important factor during rearing and laying period that affects age and body weight at sexual maturation and reproductive performance in poultry; however relevant research on this factor in pigeons is still lacking. Thus, this study investigated the effects of different photoperiodic programs on the reproductive performance and hormonal profile in White King pigeons. From 101 d of age, the pigeons in the control group were exposed to a natural photoperiod until 160 d, and then to a photoperiod of 16 h (16 light [L]: 8 dark [D]) and lasted for 200 d. Pigeons in the 3 experimental groups were exposed to a short photoperiod of 8L: 16D until 160 d, and then to 14L: 10D, 16L: 8D, and 18L: 6D, respectively. The results showed that light-restriction (8L: 16D) during the rearing period and then 14L: 10D or 16L: 8D photostimulation delayed the age at first egg laying in pigeons. However, 16L: 8D after an 8L: 16D photoperiod during the breeding period ensured maximum photosensitivity, and significantly improved the reproductive performance (egg production and fertility rates) in pigeons. Moreover, the highest reproductive performance in group under16L: 8D after 8L: 16D photoperiodic program was accompanied by improved follicle-stimulating hormone and estradiol levels and reduced prolactin hormone levels. The results indicated that photoperiodic programs from rearing to laying period are closely related to the reproductive performance of White King pigeons. The results provide information that 8L: 16D during rearing period and 16L: 8D during laying period can be used to enhance reproductive performance in the pigeon industry.

The effectiveness of Bio-plus2B®, Techno Mos® and their mixture on the rate of egg production, egg characteristics, retention of nutrients and blood metabolites through the early period of production

BackgroundThe trend of using probiotic, prebiotic and their mixture as alternative feed additives which works as growth promoters in poultry diets to increase the productive performance and the immunity of the flock still have an importance consideration. So that the aim of this study is to estimate the impact of Bio-plus2B® (probiotic), Techno Mos® (prebiotic) or their mixture (synbiotic) on egg production, egg and shell quality, some blood metabolites and retention of nutrients between 28 and 40 weeks of age. The hens (ISA brown laying) were allocated randomly in 40 cages; 10 cages/treatment with two hens each. The treatments were the control (T1), T2 (Probiotic: 1 g Bio-plus2B® (Bacillus licheniformis plus Bacillus subtilis)/kg feed), T3 (Prebiotic: 1 g Techno Mos® (Mannanoligosaccarides (MOS) and 1,3 B-glucan) /kg feed) and T4 (Synbiotic: 1 g Bio-plus2B® plus 1 g Techno Mos®/ kg feed).ResultsHen-day egg production% and mass were significantly increased (P < 0.05) with T2 and T4 treatments. The experimental treatments recorded an increase in albumen index, Haugh unit (P < 0.01), shell thickness (P < 0.05), the retention of crude protein (CP), crude fiber (CF) and ether extract (EE) (P < 0.05), plasma globulin, albumin and total protein (P < 0.001) versus to the untreated group, while egg weight was not affected. Synbiotic treatment showed a significant (P < 0.001) increase in shell calcium content. T3 and T4 treatments were significantly decreased plasma cholesterol (P < 0.001) and low density lipoprotein (LDL) (P < 0.05). Alanine transaminase (ALT) was significantly (P < 0.001) decreased and estradiol hormone was increased (P < 0.001) in the experimental groups versus to the control.ConclusionsIt concluded that adding probiotic and/or prebiotic in the early age laying hens diets had beneficial effects for productivity with improving the egg shell thickness.

Administration of ivermectin to cattle induced mortality, reduced fecundity and survivorship of Anopheles arabiensis in Ethiopia: an implication for expansion of vector control toolbox

BackgroundAlthough many countries have shown interest in eliminating malaria, approaches that complement existing vector control interventions are needed because existing methods have been scaled up but malaria still persists. Therefore, the effect of ivermectin administration to cattle was evaluated for its effect on mortality, survivorship and mortality of laboratory reared Anopheles arabiensis.MethodsThree calves were randomly selected and injected with ivermectin at a therapeutic dose of 0.2 mg/kg, while the other two calves received no treatment and served as controls. Five tents were constructed for the trial. Calves were housed in tents (one per tent) and then 30 starved female An. arabiensis were introduced into each tent. Only fully engorged females were collected from each tent and placed in different mosquito cages to monitor their mortality, survival and fecundity. Data analysis was done using SPSS version 16.ResultsDuring the follow-up period (until day 21), ivermectin induced significantly higher mortality when compared to controls. It resulted in an average 24-h mortality rate of 81.6% against An. arabiensis on the first day following treatment. 100% An. arabiensis that fed on ivermectin-treated calves on the first day after treatment died within four days. Egg production rate of An. arabiensis that fed on ivermectin-treated calves was significantly lower compared to controls (F = 768.7, P < 0.001).ConclusionIn conclusion, ivermectin induced mortality, reduced fecundity and survivorship of laboratory maintained An. arabiensis. Further study is recommended using a wild mosquito population. Moreover, mass ivermectin administration to domestic animals could be recommended to supplement the existing indoor based interventions.

Mycoplasma gallisepticum and Mycoplasma synoviae in Turkeys in Poland.

The pathogenic mycoplasmas are among the bacteria causing significant losses in the poultry industry worldwide. Mycoplasma gallisepticum (MG) and M. synoviae (MS) are economically important pathogens causing chronic respiratory disease, decreased growth, egg production and hatchability rates, and significant downgrading of carcasses. Effective diagnosis of infection with these species in poultry is highly requisite considering their two routes of spreading-horizontal and vertical. Their prevalence and molecular epidemiology were investigated in 184 turkey flocks in Poland. Tracheal samples were selected from 144 broiler flocks and 40 turkey breeder flocks collected in 2015-2023. The prevalence of MG was determined by real-time PCR targeting the 16S rRNA gene and PCR targeting the mgc2 gene, and MS was determined by a 16-23S rRNA real-time PCR and a vlhA gene PCR. Further identification and molecular characterization were carried out using PCR and sequencing. M. gallisepticum and M. synoviae were found in 8.33% and 9.72% of turkey broiler flocks respectively. The phylogenetic analysis of MG isolates in most cases showed high similarity to the ts-11-like strains. MS isolates showed high similarity to strains isolated from flocks of laying hens causing EAA. Additional tests detected Ornithobacterium rhinotracheale, Gallibacterium anatis, Enterococcus faecalis and Enterococcus faecium, Staphylococcus aureus and Riemerella anatipestifer. These secondary pathogens could have significantly heightened the pathogenicity of the mycoplasma infections studied.

Long‐term shifts in phenology, thermal niche, population size, and their interactions in marine pelagic copepods

AbstractUnder climatic warming many species shift their seasonal timing of life cycle events (phenology) and seasonal abundance distribution, but whether they maintain the same thermal niche is still poorly understood. Here, we studied multidecadal trends in abundance and phenology of seven major copepod species across three stations (Stonehaven (SH), Helgoland Roads (HR), and Plymouth L4) on the North–West European shelf, spanning ~ 6.5° of latitude. All seven species consistently occupied colder temperatures at the northern station compared to the southerly station, but they maintained the same realized thermal niche over years. Expected phenological shifts (i.e., earlier when warmer) in some stations were obscured possibly by the long‐term drop of copepod density in spring–summer, which may be due to a variation in the food/predators abundance. The ongoing spring–summer declines in abundance (~ 50%) of many North Atlantic pelagic species over the last five decades, as found in recent studies, may have also influenced the metrics of seasonal timing. To separate the seasonal timing of life events from that of seasonal abundance distribution, we used a time series of egg production rate (EPR) of Calanus helgolandicus at L4, and found that this shifted later into the summer–autumn over the last 30 yr of warming, coincident with declining spring–summer food and increasing predator abundance. Overall, direct temperature effects do appear to influence the seasonal timing of the copepods, but to explain impacts at individual stations or long‐term trends in population size or phenology, understanding the changing balance of food and predators appears to be critical.

Seasonal variation in the population structure and production of the copepod Calanus sinicus in the Yellow Sea

Abstract We estimated the total production of Calanus sinicus over four seasons by measuring somatic and egg production rates in the Yellow Sea. In the process of measuring somatic production, the length–weight relationship and growth rates of C. sinicus in this region were also derived. The population abundance and biomass of C. sinicus were especially high in spring. All copepodite stages had similar proportions in spring, whereas the late stages and adults were most common in summer. The mean total production of the C. sinicus population was 107.6–259.7 μg C m−3 day−1, ranging from higher values in spring to lower values in summer. The annual total production of C. sinicus in the Yellow Sea was 64.3 mg C m−3 year−1 (4032 mg C m−2 year−1). The production of C. sinicus was positively correlated with chlorophyll a concentration, rather than water temperature or salinity. This study is the first to quantify the secondary production of C. sinicus in the Yellow Sea. These findings will broaden our understanding of the ecology of C. sinicus and its contribution to the Yellow Sea food web.

Effects of Different Levels of Soybean Bioactive Peptides and Vitamin E on Performance, Egg Quality, and Serum Metabolites of Laying Hens

An experiment was carried out to find out how laying hen performance, egg quality, and serum metabolites were affected by adding soybean bioactive peptide (SBP) and vitamin E to their diet. Ninety Lohmann Extra hens that were 45 weeks old were divided into five groups at random. Each group consisted of three replicates, each with six birds. The dietary treatments included 250 mg/kg of vitamin E added to the baseline diet, 2.5, 5, and 7.5 g/kg of diet for the SBP groups, and the basal diet as the control. The findings demonstrated that egg production rate and egg weight significantly increased with SBP supplementation (P≤0.05). While there were no appreciable changes between the vitamin E-treated groups and the control group, there was a noticeable difference in feed efficiency between the SBP groups and the control group. Peptides-supplemented groups showed a definite advantage in terms of egg quality attributes, as evidenced by the weights of egg components, yolk index, and albumin index. The SBP supplement also resulted in an increase in glutathione peroxides (GSH-PX) and superoxide dismutase (SOD). Additionally, compared to the positive control treatment (adding vitamin E), there was a substantial (P≥0.05) drop in the cholesterol levels in the yolk among the groups supplemented with peptides. The group that got an excessive amount of soybean peptide (5 g/kg) had the highest serum total antioxidant activity. The findings concluded that adding SBP to the diets can enhance egg quality and production while also influencing the hens' serum's total antioxidant activity during the laying phase.

Dynamic Expression Profile of Follicles at Different Stages in High- and Low-Production Laying Hens.

Improving the efficiency of hens and extending the egg-laying cycle require maintaining high egg production in the later stages. The ovarian follicles, as the primary functional units for ovarian development and oocyte maturation, play a crucial role in regulating the continuous ovulation of hens. The egg production rate of laying hens is mostly affected by proper follicle growth and ovulation in the ovaries. The objective of this study was to identify the key genes and signaling pathways involved in the development of ovarian follicles in Taihang hens through transcriptome screening. In this study, RNA sequencing was used to compare and analyze the transcriptomes of ovarian follicles at four developmental stages: small white follicles (SWF), small yellow follicles (SYF), F5 follicles, and F2 follicles, from two groups: the high continual production group (H-Group) and the low continual production group (L-Group). A total of 24 cDNA libraries were constructed, and significant differential expression of 96, 199, 591, and 314 mRNAs was detected in the SWF, SYF, F5, and F2 follicles of the H and L groups, respectively. Based on the results of GO and KEGG enrichment analyses, each stage of follicle growth possesses distinct molecular genetic features, which have important effects on follicle development and significantly promote the formation of continuous production traits through the biosynthesis of steroid hormones, cytokine-cytokine receptor interaction, and neuroactive ligand-receptor interaction. Additionally, through STEM analysis, we identified 59 DEGs, including ZP4, KCNH1, IGFs, HMGA2, and CDH1, potentially associated with follicular development within four significant modules. This study represents the first transcriptome investigation of follicles in hens with high and low egg-producing characteristics at four crucial developmental stages. These findings provide important molecular evidence for understanding the regulation of follicular development and its variations.

Transcriptome analysis of hypothalamus and pituitary tissues reveals genetic mechanisms associated with high egg production rates in Changshun green-shell laying hens

BackgroundChangshun green-shell laying hens are unique to the Guizhou Province, China, and have high egg quality but relatively low yield. Egg production traits are regulated by the hypothalamus-pituitary-ovary axis. However, the underlying mechanism remains unclear. Thus, we conducted RNA sequencing of hypothalamic and pituitary tissues from low- and high-yielding Changshun green-shell laying hens to identify critical pathways and candidate genes involved in controlling the egg production rate.ResultsMore than 39 million clean reads per sample were obtained, and more than 82% were mapped to the Gallus gallus genome. Further analysis identified 1,817 and 1,171 differentially expressed genes (DEGs) in the hypothalamus and pituitary, respectively. Nineteen DEGs were upregulated in both the hypothalamus and pituitary of high-yielding chickens. The functions of these DEGs were mainly associated with ion transport or signal transduction. Gene set enrichment analysis revealed that the pathways enriched in the hypothalamus were mainly associated with gonadotropin-releasing hormone (GnRH) secretion, neurotransmitter release, and circadian rhythms. The pathways enriched in the pituitary were mainly associated with GnRH secretion, energy metabolism, and signal transduction. Five and four DEGs in the hypothalamus and pituitary, respectively, were selected randomly for qRT-PCR analysis. The expression trends determined via qRT-PCR were consistent with the RNA-seq results.ConclusionsThe current study identified 19 DEGs upregulated in both the hypothalamus and pituitary gland, which could provide an important reference for further studies on the molecular mechanisms underlying egg production in Changshun green-shell laying hens. In addition, enrichment analysis showed that GnRH secretion and signal transduction, especially neurotransmitter release, play crucial roles in the regulation of egg production.

Effects of various selenium-enriched yeasts, selenomethionine, and nanoselenium on production performance, quality, and antioxidant capacity in laying hens

This study aimed to compare the effects of various selenium (Se) sources (2 mg/kg) on the performance, quality, and antioxidant capacity of laying hens as well as the Se content in their eggs and blood. We selected 720 34-wk-old Lohmann pink-shell laying hens were randomly assigned into 6 groups and fed a basal diet (control) or a basal diet supplemented with various Se sources (Se-enriched yeast, SY-A, SY-C, SY-N; selenomethionine SM, nano-Se SN) for 16 wk. There were 10 replicates of 120 hens per group. Dietary Se supplementation increased the egg production rate of all laying hens. Egg and serum Se deposition was highest in the SM group. Yolk color scores of SY-A and SY-N groups were significantly lower than those of other groups (P < 0.01). The protein height and Haugh unit were significantly lower in the SN group than in the other groups (P < 0.05). The yolk height was significantly higher in the SN and SY-N groups than in the SY-A group (P < 0.05). Dietary supplementation of selenium can improve the antioxidant capacity of laying hens. The SOD content of SM group was significantly lower than that of SY-A and SN group (P < 0.05). The malondialdehyde (MDA) content was significantly higher in the SM group than in the SY-A group (P < 0.05). The present work empirically demonstrated that the production performance of laying hens supplemented with 2 mg/kg Se was superior to that of the hens receiving only a basal diet. The SY-C group exhibited the best production performance, the SY-A group had the highest antioxidant capacity, and the SM group produced eggs with the highest level of Se enrichment.