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Information on prolonging the storage duration of cold semen with acceptable fertility in roosters is limited. This study aimed to determine the efficiency of solid storage with the addition of various concentrations of serine to the Thai native rooster (Pradu Hang Dum) semen extender on semen quality and fertility potential during storage at 5°C for up to 120 h. Pooled semen was diluted with a base extender and a gelatin extender containing 0, 2, 4, and 6 mM serine, then stored at 5°C for 120 h. In Experiment 1, the semen quality and malondialdehyde (MDA) concentrations were assessed at 0, 24, 72, and 120 h after storage. In Experiment 2, fertility potential in terms of fertility and hatchability rates was determined using the most effective solid-storage semen from Experiment 1. Sperm quality decreased with increasing storage time (P < 0.05). The lowest semen quality was observed in the control group since T24 of storage compared with the other groups (P < 0.05). Progressive motility, viability, and mitochondrial function were higher (P < 0.05) in the extender supplemented with gelatin and serine groups than those in the gelatin alone group at T72 and T120. In the extender supplemented with gelatin and serine groups, the highest semen quality was observed in the gelatin with 4 mM serine groups. The differences among extenders supplemented with serine were insignificant (P > 0.05), and the lowest MDA was observed in the gelatin with 4 mM serine groups. The fertility and hatchability rates in gelatin with 4 mM serine at T24 were comparable to those in fresh semen (83.87 and 86.12% vs. 86.66 and 88.3%; P > 0.05). Those of T72 were significantly better than those of the control at the same hour of storage (64.08 and 71.61% vs. 52.38 and 64.48%), while those of T120 were not different among groups. In summary, a semen extender as a solid medium supplemented with 4 mM serine successfully preserved the rooster semen for a long duration up to 72 h of storage time.

The response of basilar arteries to noradrenaline varies among many animal species, but remains little studied in poultry. Accordingly, we aimed to characterize the adrenergic receptor (AR) subtypes that modulate vascular response in basilar arteries in the chicken, with isometric recording of arterial ring tension using an organ bath. We demonstrated the presence of both alpha and beta (α and β) receptor subtypes through evaluating the response to noradrenaline, with and without a range of β-AR and α-AR antagonists. The concentration-dependent relaxations then induced by a range of β-AR agonists indicated a potency ranking of isoproterenol > noradrenaline > adrenaline > procaterol. We then investigated the effects of β-AR antagonists that attenuate the effect of isoproterenol (propranolol for β(1,2,3)-ARs, atenolol for β(1)-ARs, butoxamine for β(2)-ARs, and SR 59230A for β(3)-ARs), with Schild regression analysis, ascertaining multiple β-AR subtypes, with neither the β(1)-AR nor the β(2)-AR as the dominant subtype. SR 59230A was the only antagonist to yield a pA(2) value (7.52) close to the reported equivalent for the relevant receptor subtype. Furthermore, treatment with SR 58611 (a β(3)-AR agonist) induced relaxation, which was inhibited (P < 0.01) by L-NNA and SR 59230A. Additionally, treating basilar arterial strips (containing endothelium) with SR 58611 induced nitric oxide (NO) production, which was inhibited (P < 0.01) by L-NNA and SR 59230A. Based on this first characterization of AR subtypes in chicken basilar arteries (to our knowledge), we suggest that α- and β-ARs are involved in contraction and relaxation, and that β(3)-ARs, especially those on the endothelium, may play an important role in vasodilation via NO release.

The current shift from conventional cage (CC) hen housing facilities towards cage-free (CF) hen housing in the egg industry has left many questions regarding how level of fecal exposure and exposure to other hens may influence the hen intestinal microbiota. In a previous publication we reported differences in the bacterial ileal communities and ileal morphology between hens in CC and CF production environments at a single commercial site. Here, we present the first 18S rRNA gene amplicon sequencing-based characterization of the eukaryotic ileal microbiota of adult layer hens, and their associations with intestinal health parameters and the bacterial microbiota. DNA was extracted from the ileal digesta of hens (n = 32 CC, n = 48 CF) using the Qiagen Powerlyzer Powersoil kit, followed by amplification of the V9 region of the 18S rRNA gene. Paired end sequencing was performed with the Illumina MiSeq platform, and the resulting reads were processed according to the Mothur MiSeq protocol in Mothur v1.43.0. De novo operational taxonomic unit (OTU) clustering was performed in mothur with a 99% similarity threshold, and OTUs were taxonomically classified with the SILVA SSU v138 reference database. OTUs classified as vertebrate, plant, or arthropod were removed, resulting in 3,136,400 high quality reads and 1,370 OTUs. Associations between OTUs and intestinal parameters were calculated using PROC GLIMMIX. PERMANOVA over Bray-Curtis distances revealed differences between CC and CF eukaryotic ileal microbiota at the whole community level, but no OTUs were differentially abundant after correcting for false discovery (P > 0.05; q > 0.1). Kazachstania and Saccharomyces, closely related genera of yeast, represented 77.1% and 9.7% of sequences respectively. Two Kazachstania OTUs and 1 Saccharomycetaceae OTU were positively correlated with intestinal permeability (r(2) ≥ 0.35). Eimeria accounted for 7.6% of sequences across all samples. Intriguingly, 15 OTUs classified as Eimeria were inversely associated with intestinal permeability (r(2) ≤ -0.35), suggesting Eimeria may play a more complex role in the microbiota of healthy birds than has been observed in disease challenges.

The low reproductive efficiency (RE) of geese limits their production in the poultry industry. To select ganders with high breeding potential, the effect of 3 sperm mobility ranks (SMRs; high-, medium-, and low-SMR) on the RE of naturally mating geese was determined. To exclude the confounding effect of social rank (SR) on RE in naturally mating flocks, a 2-factor nested experimental design was used to differentiate the effects of SMR and SR on RE. Twenty-seven ganders and 135 geese (Zi geese, Anser cygnoides L.) at approximately 1 yr of age were divided into 3 flocks, each of which included the 3 SMR groups. Each SMR group included 3 ganders and 15 female geese. Relative genetic contribution (RGC) is defined as the number of offspring sired by 1 male as a percentage of the entire goslings in each flock, and it was used to compare the differences in RE among ganders. The frequency of agonistic behavioral interactions (ABIs) among the ganders was video recorded in each SMR group, and the SR of each gander was determined. In total, 1,026 eggs were incubated, and 609 goslings hatched. Parent-offspring relationships among 771 individuals from the 2 generations were identified using 20 microsatellite markers, and the RGC was calculated. Results showed that the SMR and SR had significant effects on RGC in naturally mating geese (P = 0.001 and P = 0.000, respectively). Significant differences in RGC were observed among the high- and medium- and low-SMR groups, with average RGCs of 14.3, 10.6, and 8.4%, respectively. The high-SMR group had the highest RGCs in each flock, and the ganders with high SR had the highest RGCs among the 3 SMRs. The study showed that in a naturally mating geese population, selecting for the sperm mobility traits of a gander can effectively improve the RE.

The present study evaluated the effects of 3 supplemental levels of dietary genistein ingested during the late laying period (66–73 wk) of laying hens. A total of 384 Hy-Line brown hens (66 wk old) were randomly divided into 4 groups (6 replicates of 16 hens in each group), the basal diet group (CON), and groups for the basal diet supplemented with 80, 120, and 400 mg/kg of genistein, G1, G2, and G3, respectively. The results of the present study showed an increased laying rate in groups G2 and G3 (linear, P < 0.01), and decreased feed-egg ratios (linear, P < 0.05) and broken egg rate (P < 0.01) in all genistein-treated groups compared with the CON group. Moreover, the G2 group showed an increase in eggshell strength and ratio (linear, P < 0.05), whereas all genistein-treated groups saw a decrease in the L* value (linear, P < 0.01) and an increase in the a* value (linear, P < 0.05) compared with the CON group. Additionally, all genistein-treated groups had an increase in the total antioxidant capacity of plasma (linear, P < 0.05), along with reduced plasma, ovarian, and yolk malondialdehyde levels (linear, P < 0.05), compared with the CON group. The G2 group had an increase in both the superoxide dismutase activity of plasma (P < 0.01) and the total antioxidant capacity of the ovaries (linear, P < 0.05), compared with the CON group. The G3 group had an increase in both the glutathione peroxidase concentration of plasma (linear, P < 0.05) and the total antioxidant capacity of the ovaries (linear, P < 0.01), compared with the CON group. The transcript levels of nuclear factor erythroid 2-related factor 2, superoxide dismutase 1, and catalase were increased in all of the genistein-treated groups (P < 0.05) compared with the CON group, whereas heme oxygenase 1 and glutamate-cysteine ligase modifier subunit were increased only in the G2 group (P < 0.05). In conclusion, supplementation with 120 mg/kg dietary genistein had the best effect on improving the laying rate, eggshell quality, and antioxidant capacity in Hy-Line brown hens during the late laying period.

This study aimed to investigate the effects of different dietary supplementation of tomato pomace (TP) and L-arginine (L-Arg) supplementation on sperm characteristics, reproductive performance, and semen biochemical components of aged commercial male broiler breeders. Thirty Ross 308 male broiler breeders (58 wk old) were provided and assigned to 5 dietary treatment groups, including control (CON), 5% TP (TPS-5), 10% TP (TPS-10), 15% TP (TPS-15), and L-Arg supplemented (10% above the recommendation, LAS-10). The results indicated that the semen volume increased in the TPS-15 group compared to that of the LAS-10 (and CON on wk 9) throughout the study (P < 0.05). The sperm concentration significantly increased in TPS-10 and TPS-15 groups in comparison to the other experimental groups. On wk 5 and 7, the sperm viability increased in all TPS groups compared to the CON and LAS-10, while on wk 9, it only increased in the TPS-10 group in comparison to the LAS-10 group (P < 0.05). The hypo-osmotic swelling test decreased in the LAS-10 group compared to the other experimental groups on wk 5 and all TPS groups on wk 7 and 9 (P < 0.05). The sperm total motility and forward progressive motility decreased in the LAS-10 group compared to the other experimental groups (P < 0.05). In contrast, unprogressive motility and immotile sperms were increased in the LAS-10 group compared to the other experimental groups (P < 0.05). In addition, the sperm penetration and fertility rate increased in TPS-10 and TPS-15 groups in comparison to CON and LAS-10 groups (P < 0.05). However, hatchability was reduced in the LAS-10 group (P < 0.05). The semen adenosine triphosphate increased in TPS-10, TPS-15, and LAS-10 groups compared to the CON (P < 0.05). Finally, the semen TAC and superoxidase dismutase decreased in the LAS-10 group (P < 0.05), while the glutathione peroxidase increased in the TPS-15 group (P < 0.05). In conclusion, 15% dietary TPS is recommended to improve the reproductive performance of aged commercial male broiler breeders.

In contrast to the later stages of follicle development, little is known about the characteristics and mechanisms associated with early folliculogenesis in avian species. The objectives of the present study were to examine and compare the histomorphological and molecular changes of primordial, primary, and secondary follicles from duck and goose ovaries during the first 6 post-hatching week. Morphological analysis showed that the length and width of both duck and goose ovaries increased steadily during weeks 1 to 5 but increased acutely at week 6, whereas a greater increment was observed in the ovarian length of ducks than that of geese during weeks 4 to 5. Furthermore, smaller diameters of the 3 categories of follicles were observed in ducks than those in geese at the first appearance, but they reached a similar size at week 6. More importantly, secondary follicles were found in the ovaries of ducks 1 wk earlier than in those of geese. These results indicated a more rapid growth rate for ovarian follicles in ducks than in geese during early post-hatching development. At the molecular level, it was found that the mRNAs encoding follicle stimulating hormone receptor (FSHR), anti-Müllerian hormone (AMH), B-cell leukemia/lymphoma 2, and cysteine-dependent aspartate specific protease 3 (CASPASE3) were ubiquitously expressed in all ovarian follicles of ducks and geese with different expression profiles in each follicular category during the first 6 post-hatching week. Notably, transcript levels of FSHR, AMH, and CASPASE3 changed differently between ducks and geese during weeks 5 to 6, which was postulated to be one of the mechanisms inducing more rapid growth of ovarian follicles in ducks rather than in geese. In conclusion, our results revealed, for the first time, differences in early folliculogenesis, including the rate of growth of each follicular category and the timing of transition of primary to secondary follicles, between ducks and geese, and these differences could result from different expression profiles of FSHR, AMH, and CASPASE3 during early post-hatching development.

In animals, the adaptation to breed at the time of greatest survival of the young is known as seasonal reproduction. This is mainly controlled by the photoperiod, which stimulates the hypothalamic-pituitary-gonadal axis and starts the breeding season. Herein, we have determined the seasonal changes in gene expression patterns of Zhedong white geese pituitary glands under a natural photoperiodism, conducted at autumn equinox (AE), winter solstice (WS), spring equinox (SE), and summer solstice (SS). Pairwise comparisons of WS vs. AE, SE vs. WS, SS vs. SE, and AE vs. SS resulted in 1,139, 33, 704, and 3,503 differently expressed genes, respectively. When compared with SS, AE showed downregulation of genes, such as vasoactive intestinal peptide receptor, prolactin receptor, and thyroid hormone receptor beta, whereas gonadotropin-releasing hormone II receptor was upregulated, indicating that these genes may be responsible for the transition from cessation to egg laying. In addition, the expression levels of 5 transcription factors (POU1F1, Pitx2, NR5A1, NR4A2, and SREBF2) and 6 circadian clock-associated genes (Clock, Per2, ARNTL2, Eya3, Dio2, and NPAS2) also changed seasonally. Gene Ontology term and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that "response to oxidative stress" and steroid biosynthesis pathway also participate in regulating the reproduction seasonality of geese. Overall, these results contribute to the identification of genes involved in seasonal reproduction, enabling a better understanding of the molecular mechanism underlying seasonal reproduction of geese.

Sustainability of poultry farming relies on the development of more efficient and autonomous production systems in terms of feed supply. This implies a better integration of adaptive traits in breeding programs, including digestive efficiency, to favor the use of a wider variety of feedstuffs. The objective of the study was to better characterize the kinetics of development of the digestive tract in broilers, in relationship with digestive efficiency by measuring various digestive parameters as well as serum color. Absolute and relative growth of gastrointestinal tract organs were compared between 2 divergent chicken lines selected on digestive efficiency (AMEn) during 7 wk of development. We show that as early as 7 d of age, these 2 lines differs for several organs developments and that these differences remain visible later on. In addition, the allometry of the gizzard and intestine segments is different between the 2 lines, with efficient birds putting more effort in the upper part of the digestive tract during postnatal development and less-efficient birds putting more effort in the lower part of the gastrointestinal tract. Interestingly, we also showed that differences in serum pigmentation, which is a good biomarker for digestive capacity, could be a convenient diagnostic tool to discriminate between chickens with high or low digestive efficiency at early stages of development. In conclusion, this study showed that selection of chickens for AMEn had large impacts in gastrointestinal development including at early stages and is a valuable resource for further studies on the genetic and physiological control of the response of the animal to feed variations.

There are great differences in physiological and biological functions between animals of different sexes. However, whether there is a consensus between sexes in duck intestinal development and microorganisms is still unknown. The current study used Nonghua ducks to estimate the effect of sex on the intestine by evaluating differences in intestinal growth indexes and microorganisms. The intestines of male and female ducks were sampled at 2, 5, and 10 wk from the duodenum, jejunum, ileum, and cecum. Then, the intestinal length and weight were measured, the morphology was observed with HE staining, and the intestinal content was analyzed by 16S rRNA sequencing. The results showed that male ducks have shorter intestinal lengths with higher relative weights/relative lengths. The values of jejunal villus height (VH)/crypt depth (CD) of female ducks were significantly higher at 2 wk, whereas the jejunal VH/CD was significantly lower at 10 wk. There was obvious separation of microorganisms in each intestinal segment of ducks of different sexes at the 3 time periods. The dominant phyla at different stages were Firmicutea, Proteobacteria, Bacteroidetes, and Actinobacteria. The duodenal Chao index at the genus level of male ducks was significantly higher at 10 wk than that of female ducks. Significantly different genera were found only in the jejunum, and the abundances of Escherichia_Shigella, Pseudomonas, Clostridium_sensu_stricto_1, Sphingomonas, and Desulfovibrio in male ducks were higher than those in female ducks, whereas the abundance of Rothia was lower, and the abundance of viral infectious diseases, lipid metabolism, metabolism of terpenoids and polyketides, parasitic infectious diseases, xenobiotic biodegradation and metabolism, cardiovascular disease, and metabolism of other amino acids in male ducks were higher than that in female ducks, whereas gene folding, sorting and degradation pathways, and nucleotide metabolism were lower. This study provides a basic reference for the intestinal development and microbial symbiosis of ducks of different sexes.

Ambient conditions during chicken embryogenesis, such as insufficient oxygen or changes in temperature, are expected to cause permanent phenotypic changes and affect their posthatch performance. Decades of genetic selection for high growth rate resulted with various physiological and morphological changes that can affect the broiler fitness under environmental stress. To evaluate the selection effect on responses to environmental challenge during embryonic development, and the long-term implications, we have used a unique genetic line, that was not selected for over 30 yr (since 1986), as control for the modern commercial genetic line. At embryonic day 5 (E5), broiler embryos from these 2 genetic lines were divided into 2 treatments: 1) control; 2) 15% O2 concentration for 12 h/day from E5 through E12 the embryonic period of chorioallantoic membrane formation. Embryos and hatched chicks were characterized for physiological and morphological parameters. Significant differences in relative embryo weight and yolk consumption were found between the 2 lines. The modern line was characterized by a higher metabolic rate and rapid growth, supported by higher hemoglobin levels and hematocrit concentrations, whereas the 1986 line had slower metabolism, lower levels of hematocrit and hemoglobin, higher oxygen volume per 1 g of embryonic tissue indicating higher oxygen availability. Both lines exhibited changes in heart rate, and blood parameters corresponding to cardiovascular system adaptation after hypoxic exposure, seemingly implemented to increase oxygen-carrying capacity to the embryo tissues. Our finding stand in agreement that the genetic selection for high growth rate that led to higher metabolism without a fit of the cardiovascular system, increased the imbalance between oxygen supply and demand.

The objective of this study was to determine and evaluate the impact of the age and housing system on blood indicators (triacylglycerides, total cholesterol, aspartate aminotransferase, total proteins, albumin, glucose) and physical egg quality parameters (egg weight, shape index and surface area, eggshell proportion, thickness, strength, and color, albumen proportion and index, Haugh units, yolk proportion, index and yolk-to-albumen ratio) in selected native breeds of the Czech Republic (the Czech Golden Spotted hens) and Slovakia (the Oravka hens). Furthermore, the concentration of cholesterol in the yolk was determined. A total of 132 animals were used. There were 60 eggs collected from each breed at each monitored period for the evaluation of egg quality. Blood samples were taken by puncture of a wing vein. The assessments were made when the hens were of 34, 42, and 50 weeks old. Enriched cages and floor pens with litter were used as housing systems. The effects of breed, housing system, and age were observed. Furthermore, interactions among these factors were calculated. The significant effect of housing system was found in total cholesterol (P = 0.098) and aspartate aminotransferase (P = 0.0343) and the significant effect of age in total protein (P = 0.0392). The significant effect of breed (P = 0.0199), housing system (P = 0.0001), and age (P = 0.0001) was found in concentration of cholesterol in the yolk. Regarding the egg quality, the significant effect of breed (P = 0.0001) was found in eggshell color, albumen index and Haugh units, whereas the significant effect of housing system was found in egg weight (P = 0.0002), egg surface area (P = 0.0003), eggshell proportion (P = 0.0460), thickness (P = 0.0216), strength (P = 0.0049), and color (P = 0.0009). The significant effect of age was determined in all parameters except for the eggshell proportion and strength. The results represent an interesting comparison of changes in biochemical blood and egg quality parameters. It is necessary to further evaluate these indicators, especially in other genetic resources of hens, where the data are often nonexisting.

In this study, we analyzed the parent stock of ISA Brown hens reared in closed and open aviary (CA and OA, respectively) sections with regard to the productive performance of hens, hatchability, and quality of chicks. The flocks were reared (1,570 cocks and 17,515 hens) for 16 wk in a three-level aviary system. On the 7th wk of rearing, half of the birds (OA group of birds) were allowed to leave the section and use half of the area of the poultry house and to use all levels. The remaining half of the birds were kept in the CA section for the entire duration of rearing. After the duration of rearing, the birds were moved to 2 neighboring production poultry houses (OA = 680 cocks and 8,126 hens; CA = 685 cocks and 8,133 hens). Reproduction was performed in a litter system in accordance with the norms for parent stock of laying hens. During the production cycle (53 wk), laying performance, feed conversion ratio, water consumption, and mortality were analyzed. On 27th, 37th, and 49th wk of production, the following analysis was performed: rate of fertilization (%), rate of hatching (%), and quality of chick. In accordance with the results, birds in OA flock required less amount of feed (P 0.05); however, a combined analysis of all these parameters using multivariate analysis of variance demonstrated a better (P 0.05). In summary, it is possible to rear parent ISA Brown hens in open sections of aviary system without the fear of subsequent deterioration of indicators of future egg production.

The difference in microbiota was examined for breeders with different egg-laying rates, and the impact of dietary Enterococcus faecium (EF) was also determined in the present study. A total of 256 Arbor Acres broiler breeders (48-wk-old) were used in a 2 × 2 factorial design, which encompassed 2 egg-laying rate levels [average (average egg laying: AP, 80.45 ± 0.91%) and low (lower egg laying: LP, 70.61 ± 1.16%)] and 2 different dietary groups [control (no additive), 6 × 108 cfu/kg EF]. The results showed that the AP breeders presented a lower egg weight, feed conversion ratio, abdominal fat rate, and serum leptin level (P(laying) ≤ 0.05) as well as a higher egg-laying rate (P(laying)

Hexavalent chromium (Cr(VI)) has carcinogenic, nephrotoxic, hepatotoxic, and neurotoxic effects. Exposure to Cr(VI) can also lead to hematological alterations and blood biochemical changes. The literature on Cr(VI) toxicity concerns mostly adult forms of vertebrates. In this study, an attempt was made to determine the effect on the developing chicken embryo of Cr(VI) in ovo administration. It was observed that chromium affected the hatchability of chicks in a dose-dependent manner. At a dose from 25 to 250 μg per egg, Cr(VI) resulted in a statistically significant reduction of hatchability. Chromium administrated at lower doses (1.56 and 2.5 μg per egg) caused a statistically insignificant increase of hatchability. However, chromium at a level of LD50 (15.6 μg per egg) or 1/10 LD50 (1.56 per egg) did not cause major changes in hematological parameters or plasma biochemical indices in newly hatched chicks. The same doses did not lead to any histopathological changes in the liver.

A functional fatty acid taste receptor, GPR120, is present in chicken oral tissues, and chickens show a preference for lipid in feed. However, it remains unclear whether chickens can detect fatty acids. To address this issue, we adopted 2 behavioral paradigms: a one-bowl drinking test to evaluate the preference for oleic acid solution and a conditioned taste aversion test to investigate the role of gustation in chickens' ability to detect oleic acid. In the one-bowl drinking test, chickens did not show any preference for solution containing 0.001, 0.01, 0.03, 0.1, or 30 mmol/L oleic acid although 30 mmol/L oleic acid was enough to fully activate GPR120, confirmed by Ca2+ imaging. On the other hand, chickens conditioned to avoid 30 mmol/L oleic acid solution also learned to avoid the solution. These results suggested that chickens have a gustatory perception of oleic acid solution but do not have a preference for it. The present results support the idea that chickens prefer lipid in feed, not only by a postingestive effect but also by sensing the taste of fatty acid.

The molecular mechanisms underlying reproductive aging in avian species are poorly understood. Previous studies have shown the importance of mechanistic target of rapamycin (mTOR) signaling pathway in aging. In this study, we investigated the relationship between the mTOR signaling pathway and ovarian aging in the peak phase and late phase of egg production in laying hens. The egg production rate and egg quality were tracked for 5 consecutive weeks in 30-week-old and 70-week-old Dawu Jinfeng hens (N = 30/group). During the peak phase (week 35) and late phase (week 75), antioxidant and immune indicators were detected by enzyme-linked immunosorbent assay, and mTOR signaling-related genes (CLIP-170, GRB10, LIPIN-1, ATG1, 4E-BP1, S6K, PKC, RHO, and SGK1) were detected in the follicles by quantitative reverse transcription-PCR technology. The protein expression of key genes (mTOR, PKC, 4EBP1) was evaluated by Western blot analysis. The egg production rate and the antioxidant indexes superoxide dismutase and glutathione peroxidase and the levels of total antioxidant capacity and immunoglobulins (IgM and IgG) were significantly higher at week 35 than those at week 75 (P

The Green-legged Partridgelike fowl is an old Polish indigenous breed of chicken. Primordial germ cells (PGCs) are one of the best sources of precursor cells that can be used for the conservation and proliferation of the endangered breeds of bird. Initially, the chicken PGCs colonize at the anterior extraembryonic region called “germinal crescent,” and after the establishment of blood vascular circulation, they temporally circulate via the embryonic blood vascular system along with embryonic blood cells. They further colonize at the microcapillary networks of both right and left future gonadal regions. Subsequently, they migrate interstitially to reach gonadal anlages, where they begin to differentiate and eventually develop into the future ova or sperm. The basic knowledge regarding the concentration and the total number of circulating PGCs (cPGCs) throughout their circulating phase in the early embryonic stages is crucial for providing an insight into the mechanisms by which they circulate and colonize at the capillary networks of left and right future gonadal regions in each developmental stage. The present study aims to determine the most efficient developmental stage that is suitable to collect cPGCs. The concentration of cPGCs was directly measured, and total volume of embryonic blood was calculated based on the concentration of PKH26-stained embryonic blood cells which were injected 10 min before the blood sampling process in the same embryo during each stage of embryonic development from stage 13 Hamburger and Hamilton (HH; Hamburger and Hamilton, 1951 ) to 16 HH. Analysis of whole embryonic bloodstream revealed that at stage 14 HH of embryonic development, peak total number of cPGCs (386.3 cells/μL) and peak concentration of cPGCs (18.6 cells/μL) were observed. Later, there was a decrease in concentration, suggesting that the cPGCs might be trapped gradually by the capillary networks at the future gonadal regions after stage 15 HH.

Oxidative stress could be prevented by antioxidant-loaded nanoparticles. The purpose of this study was to assess the effects of 10 (A10), 20 (A20), 30 (A30), 40 (A40), and 50 (A50) μM alpha-lipoic acid and alpha-lipoic acid nanostructured lipid carriers (ALN) at 10 (ALN10), 20 (ALN20), 30 (ALN30), 40 (ALN40), and 50 (ALN50) μM on post-thawed sperm quality, fertility, and apoptosis-related genes of rooster sperm. The extender supplemented with ALN30 led to higher total and progressive motility, straight-line velocity, and linearity in comparison to the control group. The ALN30 resulted in higher percentage of mitochondria activity and glutathione peroxidase level compared with control (P < 0.05). The extender supplemented with ALN30 led to lower percentage of apoptotic sperm, when compared with the control. CASPASE 3 expression in ALN30 was lower (P

Cage layer fatigue (CLF), which is commonly caused by calcium deficiency in the feed, leads to loss of structural bone and increase of bone fragility. In order to investigate the influence of low-calcium diets on bone quality and strength, histopathology, and egg quality, 72 laying hens were randomly allocated to 2 groups at 22 wk of age and received low calcium and control calcium until 34 wk, respectively. Egg production, feed consumption, BW, and egg quality were measured throughout. Bone mineral density, bone biomechanical properties, and histomorphology of femurs and tibias were assessed after birds were sacrificed in 26, 30, and 34 wk. The results showed that low-calcium (1.5%) diets decreased BW, feed consumption, and egg production. The broken eggs rate increased, and the eggshell strength and thickness were lower in treated birds than those in control birds at 30 wk and 34 wk. Femoral and tibial bone index and bone mineral density were lower, cortical thicknesses were thinner, and bone length were shorter over time when birds are in a low-calcium diet than those in control birds. In biomechanical properties, the values of stiffness, Young's modulus, and breaking strength were lower in both femurs and tibias in low-calcium hens at 30 wk and 34 wk than those in bones of control hens. In histomorphology of bone, the cortex turned thinner and there were more cavities in cortex and cancellous bone; the trabecular bone network was fewer, thinner, less cohesive, and generally fragmented; and trabeculae were less well-connected in low-calcium birds. Some cell nuclei in cancellous bone disappeared, and vacuolation was observed in bone cells. There appeared osteoid in cortex bone and cancellous bone in tibias. It was concluded that low-calcium diets could facilitate the development of osteoporosis characterized by an increase of osteoid and loss of structural bone and decrease the values of bone quality and strength, accompanied with a decrease in egg production and egg qualities, which may elucidate the developing mechanism of CLF.

The purpose of this study was to investigate whether dietary nuciferine affects lipid metabolism in broiler chickens. Four treatment groups were made from 120 1-day-old broiler chickens including the base diet group (normal control [NC], supplemented with 0 mg/kg of nuciferine) and groups treated with 25 mg/kg, 100 mg/kg, and 400 mg/kg of dietary nuciferine, which was supplemented for 42 d. The results showed that body weight, average daily weight gain, and absolute and relative fat and liver weight were significantly decreased with nuciferine supplementation. The plasma concentration of triiodothyronine, free triiodothyronine, thyroxine, and free thyroxine was significantly decreased in the nuciferine-supplemented group, but the plasma glucagon concentration was significantly increased. The plasma and hepatic triglyceride (TG) and total cholesterol (TC) concentrations were significantly decreased in the nuciferine group, but plasma and hepatic nonesterified fatty acid concentration, hepatic lipase activity, and hepatic glycogen content were significantly increased. Hepatic histological examination showed that fat cell volume and size in the 100 and 400 mg/kg group were smaller than those in the NC group. The fatty degeneration in the liver was decreased with nuciferine supplementation. The fat cell volume and size were shrunk in the nuciferine group. Dietary nuciferine supplementation significantly decreased the gene expression level of HMGCR, SREBP2, ACC, and SPEBP-1C, but significantly increased the gene expression level of LXR-α, CYP7A1, and CPT-I. The results indicated that nuciferine exhibited strong reduced fat deposition activities and reflected not only by decrease of the concentration of TG and TC but also by reduction in the key gene expression level of HMGCR, SREBP2, ACC, and SPEBP-1c and elevation of the key gene expression level of LXR-α, CYP7A1, and CPT-I. Taken together, our results suggested that the ability of nuciferine on reducing fat deposition in broiler chickens by regulating lipid metabolism was associated with the balance of TG and TC concentration.

Biobanking of turkey ovarian tissue appears to be the most cost-effective method for the long-term preservation of female genetics. However, to ensure the successful transplantation of biobanked ovarian tissue for breed or line revival, the transplantation and development of fresh ovarian tissue must be evaluated. To assess transplantability, ovaries from poults 1 to 15 days posthatch (dph) were cultured in ovo in chicken eggs for 6 d and compared with the equivalent fresh tissue. The viability of cultured ovarian tissue was evaluated visually, whereas the level of late-stage apoptosis was measured via the TUNEL assay. In addition, the diameter and density of prefollicular germ cells and follicles (primordial and primary) were measured to assess maturation. Results showed that all cultured grafts (74/74), on surviving chicken chorioallantoic membrane, were viable with low levels (0.8 ± 0.1%) of late-stage apoptosis. The diameter of prefollicular germ cells in cultured ovaries from poults at 5 and 7 dph were larger (P

Decades of intensive genetic selection in commercial layers has resulted in earlier maturation, while sustaining high production rates to 100 wks of age (woa). To support eggshell formation while maintaining a healthy skeletal frame, substantial adaptations of calcium metabolism in the hen are necessary. Thus, skeletal growth, bone density, and egg quality were compared in 3 strains of layers, with the Lohmann LSL-lite as the current commercial strain, the heritage Shaver white leghorn as the mid-2000s strain, and the white-leghorn derived Smoky Joes as the non-selected 1960s strain. Tibia and Femur (n = 4/strain) were collected at 12, 17, 20, 25, 45, 60, 75, and 100 woa. Bones were measured and weighed, with bone mineral density assessed within medullary (mBMD) and cortical (cBMD) regions of the tibia using micro-Computed Tomography. Egg analyses including weight, eggshell thickness (EST) and eggshell breaking strength (EBS), were conducted throughout lay. Blood samples were collected to measure plasma calcium immediately prior to lay (18 woa) and periodically throughout the laying cycle. Femur and tibia weight, or size, did not increase beyond 12 woa, indicating that all hens reached maximum skeletal size by this time. An interaction (P = 0.005) was observed between strain and tibia mBMD, as all three strains demonstrated an accumulation of medullary bone from 12 to 100 woa. Regarding egg weight, while Lohmann hen eggs displayed the highest quality at 26 woa, an elevation in egg weight in Lohmann and Shaver hens (P < 0.001) resulted in a decline in EST and EBS over time (P < 0.01). Yet, at 100 woa, no strain differed in EST or EBS, despite larger variations in cumulative egg numbers (P < 0.001). Plasma calcium levels were significantly elevated between the immature state and peak of lay but remained unchanged throughout lay in all strains. In conclusion, our results show that although genetic selection of layer hens resulted in tremendous improvement in productivity, no detrimental effects on cBMD or mBMD were observed throughout an extended laying period up to 100 woa.

It's a difficult task for researchers to identify the gender of chicken eggs by non-destructive approach in the early of incubation, which not only could reduce the cost of incubation, but also could improve the welfare of chicks. Therefore, SPME/GC-MS has been applied to investigate its potential as a non-destructive tool for characterizing the differences of odor between male and female chicken eggs during early of incubation and even before hatch. The results showed that more volatiles were found in female White leghorn eggs during early of incubation and 6,10-dimethyl-5,9-undecadien-2-one, 6-methyl-5-hepten-2-one, nonanal, decanal, octanal, 2-nonen-1-ol, etc. were important for the distinction of male and female White leghorn eggs during E1-E9 of incubation. 2-ethyl-1-hexanol; octanal, nonanal, 2,2,4-trimethyl-3-carboxyisopropyl pentanoic acid isobutyl ester; 2-nonen-1-ol, cyclopropanecarboxamide, heptadecane were correlated with gender of unhatched White leghorn, Hy-line brown and Jing fen eggs, respectively. Moreover, sex-related volatiles have been strongly influenced by incubation process and egg breed, and to be related to steroid hormone biosynthesis. What's more, this study enables us to develop a new visual for ovo sexing of chicken eggs and advances our understanding of the biological significance behind volatiles emitted from chicken eggs.

Antioxidant nanoparticles include the potential for improving sperm cryopreservation. The aim of performing this study was to evaluate the effects of gamma-oryzanol (GO) at 0 (C) (control group), 20 (GO20), 40 (GO40), 60 (GO60), 80 (GO80), and 100 (GO100) µM and gamma-oryzanol nanoparticles (GON) at 0 (CN), 20 (GON20), 40 (GON40), 60 (GO60), 80 (GON80), and 100 (GON100) µM on post-thawed sperm quality and fertility of rooster sperm. Sperm motility, plasma membrane integrity, total abnormality, mitochondrial activity (Rhodamine 123), apoptotic features (Annexin V/Propidium iodide), reactive oxygen species (ROS) production, ATP content and the fertility and hatchability were evaluated after thawing. Total motility in GON60 and GON80 were significantly higher compared to control groups (C and CN). GON80 showed the greatest percentages of progressive motilities. When GO80, GON60, and GON80 were added to the cryopreservation medium, the plasma membrane functionality of the semen samples improved. The minimum abnormality of spermatozoa is observed in the group treated with GON80. The groups treated with GON60 and GON80 had greater (P < 0.05) mitochondrial activity. The level of sperm ROS after cryopreservation was significantly lower in GON60 and GON80 groups. Live sperm was significantly higher (P < 0.05) in GON60 and GON80 group compared to other groups. GON60 and GON80 groups also led to the lowest significant percentage of apoptosis-like change sperm. Greater fertility percentages were observed (P < 0.05) when sperm were stored in extenders treated with GON60 and GON80. GON80 resulted in significantly improved hatched eggs compared to C, GO60, GO180 and CN. In conclusion, supplementation of Lake extender with 60 and 80 µM gamma-oryzanol nanoparticles could be a proper process to improve freeze-thawing rooster sperm quality leading to better freeze/thaw characteristics.

This experiment was conducted to investigate the effects of manganese (Mn) and Bacillus subtilis (BS) on the production performance, egg quality, antioxidant capacity, and gut microbiota of breeding geese during laying period. A total of 120 forty-six-week-old breeding geese (Wulong) were randomly assigned to 1 of 6 treatment diets formulated to supply 10, 20, and 30 mg/kg Mn with 5 × 109 CFU/kg or 2.5 × 109 CFU/kg BS for a 10-wk trial. Results showed that dietary supplementation with 20 and 30 mg/kg Mn could decrease the daily feed intake (DFI) of geese. Moreover, 30 mg/kg Mn significantly increased the laying rate. Besides, although Mn addition had no obvious effect on egg quality, 5 × 109 CFU/kg BS was found to elevate the hatching egg hatching rate and eggshell thickness. For the serum hormones, 30 mg/kg Mn promoted estradiol secretion, while 5 × 109 CFU/kg BS increased the level of follicle-stimulating hormone. Furthermore, 20 and 30 mg/kg Mn and 5 × 109 CFU/kg BS significantly enhanced the total antioxidant capacity by increasing the activity of total superoxide dismutases or decreasing the content of malondialdehyde. Dietary supplementation with 5 × 109 CFU/kg BS also increased the intestinal villus height and upregulated the abundance of Fusobacteria, Fusobacteriaceae, Fusobacterium, and Faecalibacterium in cecal content. In addition, 20 and 30 mg/kg Mn elevated the levels of Bacteroidetes, Bacteroidaceae, Bacteroides, and Ruminococcaceae but decreased Streptococcaceae. Importantly, an interaction effect was observed between Mn and BS on the DFI, egg mass, average egg size, and the abundance of Bacteroides as well as Faecalibacterium. In conclusion, dietary inclusion of Mn and BS could improve the production performance, egg quality, antioxidant capacity, intestinal structure, as well as gut microbiota. Supplementation of 30 mg/kg Mn and 5.0 × 109 CFU/kg BS provided the optimal effect.

A 3 × 2 factorial arrangement of treatments was conducted to investigate the effects of iron (Fe, 40, 60, and 80 mg/kg) and Bacillus subtilis (2.5 × 109 and 5.0 × 109 CFU/kg) supplementation on reproductive performance, egg quality, nutrient digestibility, hormone levels, antioxidant indices, and hematological parameters in breeder geese. A total of one hundredtwenty 46-week-old Wulong breeder geese were randomly assigned to 1 of 6 dietary treatments with 4 replicates per treatment and 5 geese per replicate for 10 wk following 1 wk of adaption. Dietary Fe supplementation increased egg weight (P = 0.036), fertility (P = 0.022), serum total antioxidant capacity (P = 0.022), red blood cell (P = 0.001), hematocrit (HCT, P

Low-egg-producing hens (LEPH) ovulate less frequently than high-egg-producing hens (HEPH) and exhibit differences in mRNA levels for components of the hypothalamo–pituitary–gonadal (HPG) axis, suggesting differential responsiveness to trophic stimulation. Ovulation frequency is governed by the production of the pituitary gonadotropins and feedback of the ovarian follicle steroid hormones, which are regulated by HPG axis stimulation and inhibition at the hypothalamic level. The pituitary and follicle cells from LEPH and HEPH were subjected to in vitro hormonal treatments to stimulate or inhibit the HPG axis, followed by expression analysis of mRNA levels for HPG axis genes and radioimmunoassays for steroid hormone production. Statistical analysis was performed using the mixed models procedure of SAS. The pituitary cells from HEPH showed upregulation of genes associated with ovulation stimulation, whereas cells from LEPH showed upregulation of genes associated with inhibition of ovulation. High-egg-producing hens’ follicle cells displayed a higher sensitivity and responsiveness to gonadotropin treatment. Level of egg production impacted ovulation-related gene expression in the pituitary cells as well as steroid hormone production in the follicle cells, with HEPH displaying a greater positive response to stimulation. These findings indicate that differences in egg production among turkey hens likely involve differential responsiveness of the cells within the HPG axis.

The yolk sac tissue (YST) is a multifunctional metabolic organ supporting chicken embryonic development. This study examined whether incubation temperatures (ITs) affect YST functions. For this purpose, 300 eggs were assigned to 3 groups and incubated at control IT of 37.8°C, at 1.5°C below, 36.3°C (cold IT), and at 1.5°C above, 39.3°C (hot IT). For each group, 6 embryos' whole body mass and residual yolk (RSY) weights were recorded during incubation, and YST was sampled for both histology and gene expression analysis. YST functionality during incubation was examined by regression analysis, comparing changes in expression patterns of genes involved in lipid uptake and metabolism (LRP2, ApoA1), oligopeptides uptake (PepT1), gluconeogenesis (FBP1), glycogenesis (GYS2), and thyroid hormones regulation (TTR, DIO1, DIO2). Results show that hot and cold ITs affected YST gene expression and yolk utilization. PepT1 expression decreased towards hatch, in both hot and cold ITs, while in the Control IT, it reached a plateau. ApoA1 and DIO2 expression showed a moderate linear fit compared to polynomial fit in the control. GYS2 expression had no change along incubation, while in the control IT, it showed a polynomial fit. Expression of LRP2, FBP1, and DIO1 genes was affected by either cold or hot IT's. TTR expression patterns were similar in all IT groups. The variations in gene expression patterns observed in the 3 ITs can explain the changes in yolk utilization, an important parameter for hatchling quality. While the control IT showed optimal utilization, with an RSY value of 11.12% at the day of hatch, the cold and hot IT groups exhibited lower utilization with an RSY value of 18.18 and 29.99%, respectively. These findings are the first to show that ITs change the expression of key YST genes, leading to variations in yolk utilization by the embryo.

Heat stress (HS) causes significant economic losses in the poultry industry every year. However, the mechanisms for the adverse effects of HS on avian follicular development are largely unknown. The aim of this study was to test whether HS induces apoptosis of follicular cells and impairs egg production by activating the FasL/Fas and tumor necrosis factor (TNF)-α systems. To this end, Hy-Line Brown laying hens, at 32 wk of age, were either exposed to HS of 35°C to 37°C or maintained at 24°C to 26°C (control) for 5 D. At the end of the HS period, follicle numbers, apoptosis, FasL/Fas and TNF-α activation, oxidative stress, and hormone secretion were examined in ovarian follicles. Egg production was observed daily during both the stressed (day S1–S5) and the poststress recovery (day R1–R15) periods. The results demonstrated that HS on hens significantly 1) decreased laying rates from day S3 to R6; 2) reduced numbers of large yellow and hierarchical follicles; 3) triggered apoptosis while increasing the expression of FasL, Fas, TNF-α, and TNF-receptor 1 in small and large yellow follicles; and 4) increased levels of oxidative stress, corticotrophin-releasing hormone, and corticosterone while decreasing the estradiol/progesterone ratio in follicular fluid in small and large yellow follicles. Taken together, the results suggested that hen HS impaired egg production by reducing the number of follicles through inducing apoptosis and that it triggered apoptosis in follicular cells by activating the FasL/Fas and TNF-α systems.

Sperm mobility is a major determinant of sperm quality in the domesticated chicken (Gallus domesticus) and is therefore an area of interest for improving fertility. Sperm-associated antigen 6 (SPAG6) is an important flagellar protein implicated to be necessary for flagellar function but negatively associated with rooster fertility. This study was aimed to characterize the expression of SPAG6 and investigate its utility as a protein biomarker of sperm mobility. By western analysis, relative SPAG6 abundances were compared between the testicular, epididymal, and vasal tissues and in sequentially maturing sperm. Immunocytochemistry techniques were used to detect localization of SPAG6 in chicken sperm. Last, western analysis was used to compare relative SPAG6 abundances in sperm of differing mobility. SPAG6 was found in higher abundance in epididymal tissues and in highest abundance in vasal tissues, relative to that of the testis. SPAG6 was also found to sequentially increase in abundance in maturing sperm. SPAG6 localizes between the axonemal central pair of microtubules in the sperm flagella, but it is also found in lower concentration in the acrosomal region. SPAG6 was not a significant predictor of sperm mobility. SPAG6 abundance, alone, is not a strong predictor of sperm mobility. Its impact on rooster fertility is likely unrelated to its impact on sperm mobility.

Previous studies have suggested the use of probiotics, as alternative to antibiotics, to enhance broiler performance. The administration of probiotics in feed has been widely explored; however, few studies have evaluated the in ovo inoculation of probiotics. Therefore, the objective was to evaluate the impact of in ovo inoculation of different concentrations of GalliPro Hatch (GH), an Enterococcus faecium-based probiotic, on hatchability, live performance, and gastrointestinal parameters. Ross x Ross 708 fertile eggs were incubated, and on day 18, injected with the following treatments: 1) 50 μL of Marek's vaccine (MV), 2) MV and 1.4 × 105 cfu GH/50 μL, 3) MV and 1.4 × 106 cfu GH/50 μL, 4) MV and 1.4 × 107 cfu GH/50 μL. On the day of hatch, chicks were weighed, feather sexed, and hatch residue was analyzed. Male birds (640) were randomly assigned to 40 floor pens. On day 0, 7, 14, and 21 of the grow-out phase, performance data were collected. One bird from each pen was used to obtain yolk weight and intestinal segment weight and length. Hatchability was not impacted by any GH treatment (P = 0.58). On day 0, yolk weight was lower for all treatments than for MV alone. On day 0 to 7, feed intake was lower for 105 and 107 GH; the feed conversion ratio (FCR) was lower for all treatments than for MV alone (P = 0.05; P = 0.01, respectively). From day 14 to 21, the 107 GH treatment had higher BW gain (P = 0.05). For day 0 to 21, 107 GH had a lower FCR than MV alone (P = 0.03). On day 0, all GH treatments resulted in heavier tissues and longer jejunum, ileum, and ceca lengths than MV alone (P < 0.05). Spleen weight was higher for 105 and 107 GH than for MV alone. In conclusion, GH does not impact hatchability, and some concentrations improved live performance through the first 21 d of the grow-out phase. These improvements could result from the increased yolk absorption and improved intestinal and spleen morphology seen in this study.

Glycerol is the most widely used cryoprotectant for rooster sperm because it declines the mechanical damage to sperm during the freezing process. Despite its high molecular weight and viscosity, which may be cytotoxic, glycerol can cause damage to cells during the cryopreservation process, resulting in less fertility. Poloxamer 188 (P188) is an embryo cryopreservation supplement effective in many species and also for cell lines and plant cells. We tested the suitability of P188 in the cryopreservation of rooster sperm, considering post-thawing motility, abnormalities, membrane functionality (hypo-osmotic swelling test), mitochondrial activity, viability, apoptosis status, reactive oxygen species production, and ATP content after thawing and the fertility and hatchability after AI. We carried out a factorial experiment with glycerol concentrations of 2% glycerol (G2) and 8% glycerol (G8) and P188 concentrations of 0% (P0), 0.1% (P0.1), 0.5% (P0.5), and 1% (P1) as fixed effects, with replicate (seven) as a random effect. Interactions between glycerol and P188 were found, with G2P1 yielding higher quality and fertility. G8P0.5 yielded better in most parameters, however, not reaching G2P1. G2P1 showed significantly higher results for total and progressive motility, kinetic parameters (average path velocity, straight-line velocity, and linearity), membrane functionality, viability, mitochondrial activity, and ATP content and lower apoptosis, dead sperm, and reactive oxygen species production. G2P1 resulted in the highest percentages of fertilized and hatched eggs, with no effects in the hatched eggs ratio. Interestingly, G2 was less efficient in many parameters than G8 when combined with P0 and P0.1, being equivalent to G8 with P0.5 and superior to any G8 treatment as G2P1. In conclusion, P188 could improve rooster semen cryopreservation and allow reduction of glycerol in extenders, with a consequent impact in the poultry industry.

Melatonin is a key regulator of follicle granular cell maturation and ovulation. The mammalian target of rapamycin (mTOR) pathway plays an important role in cell growth regulation. Therefore, our aim was to investigate whether the mTOR signaling pathway is involved in the regulation of melatonin-mediated proliferation and apoptotic mechanisms in granulosa cells. Chicken follicle granular cells were cultured with melatonin (0, 2, 20, or 200 μmol/L) for 48 h. The results showed that melatonin treatment enhanced proliferation and suppressed apoptosis in granular cells at 20 μmol/L and 200 μmol/L (P < 0.05) by upregulation of cyclin D1 (P < 0.01) and Bcl-2 (P < 0.01) and downregulation of P21, caspase-3, Beclin1, and LC3-II (P < 0.01). The effects resulted in the activation of the mTOR signaling pathway by increasing the expression of avTOR, PKC, 4E-BP1, S6K (P < 0.05), p-mTOR, and p-S6K. We added an mTOR activator and inhibitor to the cells and identified the optimal dose (10 μmol/L MHY1485 and 100 nmol/L rapamycin) for subsequent experiments. The combination of 20 μmol/L melatonin and 10 μmol/L MHY1485 significantly enhanced granulosa cell proliferation (P < 0.05), while 100 nmol/L rapamycin significantly inhibited proliferation and enhanced apoptosis (P < 0.05), but this action was reversed in the 20-μmol/L melatonin and 100-nmol/L rapamycin cotreatment groups (P < 0.05). This was confirmed by mRNA and protein expression that was associated with proliferation, apoptosis, and autophagy (P < 0.05). The combination of 20 μmol/L melatonin and 10 μmol/L MHY1485 also activated the mTOR pathway upstream genes PI3K, AKT1, and AKT2 and downstream genes PKC, 4E-BP1, and S6K (P < 0.05), as well as protein expression of p-mTOR and p-S6K. Rapamycin significantly inhibited the mTOR pathway–related genes mRNA levels (P < 0.05). In addition, activation of the mTOR pathway increased melatonin receptor mRNA levels (P < 0.05). In conclusion, these findings demonstrate that melatonin regulates chicken granulosa cell proliferation and apoptosis by activating the mTOR signaling pathway via its receptor.

This experiment aims to study the effects of dietary selenium (Se) sources on the production performance, reproductive performance, and maternal effect of breeder laying hens. A total of 2,112 Hyline brown breeder laying hens of 42 wk of age were selected and randomly divided into 3 groups, with 8 repeats in each group and 88 chickens per repeat. The sources of dietary Se were sodium selenite (SS, added at 0.3 mg/kg), L-selenomethionine (L-SM, added at 0.2 mg/kg), and combination of SS and L-SM (SS 0.15 mg/kg + L-SM 0.15 mg/kg). The pretest period was 7 d, and the breeding period was 49 d. Compared with 0.3 mg/kg SS, the addition of 0.2 mg/kg L-SM in the diet significantly increased the hatchability (P

Improvac has been tentatively used to immune-castrate roosters. The aim of this study was to investigate whether Improvac affected skeletal muscle development in chickens. The muscle fiber type and size and the expression levels of genes related to muscle development in pectoral and thigh muscles were examined at 5, 9, and 14 wk of age in the control, early, late, and early + late Improvac-treated groups. Immunocastration with Improvac affected the development of thigh muscles and the expression of MYH1B, MSTN, and SM. The cross-sectional area in the early group was significantly larger than in the control group at the 14th week (P < 0.01). At the fifth week, the expression levels of MYH1B, MYOD, and MSTN in the early group were significantly higher than those in the control group (P

Reproductive failure associated with heat stress is a well-known phenomenon in poultry. High temperatures also induce various metabolic disturbances in many animals. Because the liver plays a central role in metabolism, the present study aimed to clarify the relationship between liver and reproduction in Japanese quails exposed to high temperatures. In the consecutive 20-D experimental period, quails were treated with 25°C (control) or 34°C (heat) from 12:00 to 16:00. Eggs were collected for hatching. On completion of the experimental period, quails were humanely euthanized for hormone analyses (e.g., serum and ovarian follicles). Serum metabolites were analyzed using GC/MS. Liver and ovary samples were collected for mRNA levels, histomorphology, and metabolic analysis. Ovary and oviduct weights significantly decreased after daily heat exposure. The number and weight of hierarchical follicles also decreased. Consequently, egg weight decreased. Although there was no difference in fertilization rate, chick birth weight significantly decreased in the heated group. Corticosterone and 17β-estradiol in the serum significantly increased in the heated group. Yolk corticosterone and 17β-estradiol concentration and content were higher in the heated group. Ovary sterologenic enzymes gene P450scc and estrogen receptor expression level increased. The FSH receptor decreased in heat-stressed quails. MetaboAnalyst analysis indicated that high temperature affects propanoate metabolism, beta-alanine metabolism, aspartate metabolism, and histidine metabolism. Triglyceride and cholesterol levels in the liver increased in the heated group. The heated group also had an increased mRNA expression of AGPAT5, apoptosis gene caspase3, and the immunocytokine genes IL-6 and TLR4. However, NF-κB gene expression decreased. These results suggest that high temperatures affect lipid metabolism and apoptosis and cause inflammation in the liver. High temperature induced ovarian dysfunction, which resulted in the decline of hierarchical follicle number and weight, egg weight, and chick birth weight. The increased level of 17β-estradiol suggests liver damage. Protecting liver function from damage may assist quails cope in summer.

Methionine (Met), an essential amino acid in poultry diets, when overdosed may cause hyperhomocysteinemia, which is mainly a trigger for cardiovascular diseases in humans. Homocysteine is neutralized (remethylated) in the presence of folic acid (FA), which also plays an important role in hematopoiesis and participates in the synthesis of DNA, and its deficiencies may result in the development of neural tube defects. One of the basic tools in studying the impact of both xenobiotics and nutrients on the animal organism is hematological analysis. Thus, the aim of this study was to determine the effect of in ovo supplementation with Met and FA on the hematological parameters of broiler chickens. On the 17th day of incubation, embryonated eggs (Ross 308) were injected with 5 or 25 mg of Met per egg (M5 and M25), 3 and 15 mg of FA per egg (F3 and F15), or a mixture of these 2 compounds (M5/F3 and M25/F15). The broilers were reared in accordance with welfare regulations and fed with commercial diets ad libitum. Blood samples were collected on the first, seventh, and 35th day of rearing (D1, D7, and D35), and complete hematological analysis was performed. The observed changes in red blood cell parameters probably result from physiological changes occurring during bird growth. Mean erythrocyte volume decreased with the age of chickens in the control, M5, and M25 groups, but not in those supplied with FA. Among supplemented groups, the number of white blood cells on D1 was lower only in group M5 than in the sham (C) group. The analysis of leukograms showed no significant differences between the groups. Comparing D1 with D7 in the group injected with a higher dose of Met and FA (MF25/15), a statistically significant increase in the percentage of lymphocytes and a significant decrease in the percentage of heterophils were observed. In addition, in the group injected with a higher FA dose (F15), there was statistically significant reduction in the percentage of eosinophils and a significant increase in the percentage of monocytes at day 7 compared with day 1. It seems that Met supplementation led to temporary immunosuppression in the animals.

Egg quality defects seriously reduce the quality grade and increase egg breakage in egg marketing activities. In this study, the effect of N-carbamylglutamate (NCG) on eggshell quality was investigated by evaluating calcium absorption and calcification in laying hens. A total of 30 newly hatched female Hy-Line chicks were randomly assigned to the control group (basal diet) and treatment group (basal diet supplemented with 1% NCG). At 25 wk, eggs from each group were obtained to assess egg quality parameters. Blood samples were collected for analysis of mineral, hormone, and amino acids levels at 16 h after laying egg. Uterine tissues were removed and fixed in 4% neutral paraformaldehyde solution or kept in liquid nitrogen for mineral determination, quantitative PCR, and Western blot. Results showed that the egg quality (eggshell thickness, strength and percentage, egg specific gravity, and eggshell effective thickness) was significantly increased while effective thickness of mastoid layer, width of mastoid gap, and mammillary knobs were significantly decreased by dietary NCG supplementation (P

Heat stress (HS) is a major problem in poultry business which affects chickens' performance and may trigger large economic losses. This study intends to analyze the impact of HS on broiler chickens' performance compared with those under normal condition. A literature search was performed on PubMed, Web of Science, and Cochrane Library for studies published in English up to January 17, 2020. Outcomes of body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), and mortality were calculated by weighted difference (WMD) or odds ratio (OR) with 95% confidence interval (CI). A total of 12 studies with 470 broiler chickens were included. HS significantly decreased FI (11 trials: WMD = −97.95, 95% CI: −141.70, −54.20) and BWG (7 trials: WMD = −151.40, 95% CI: −198.59, −104.21) and significantly increased FCR (9 trials: WMD = 0.17, 95% CI: 0.04, 0.29) and mortality (8 trials: OR = 3.74, 95% CI: 1.39, 10.12) compared with the control. In conclusion, HS significantly affected broiler chickens' BWG, FI, FCR, and mortality, indicating the importance to control housing temperature to avoid unnecessary costs.

The application of transcriptomics to the study of the reproductive tract in male turkeys can significantly increase our current knowledge regarding the specifics of bird reproduction. To characterize the complex transcriptomic changes that occur in the testis, epididymis, and ductus deferens, deep sequencing of male turkey RNA samples (n = 6) was performed, using Illumina RNA-Seq. The obtained sequence reads were mapped to the turkey genome, and relative expression values were calculated to analyze differentially expressed genes (DEGs). Statistical analysis revealed 1,682; 2,150; and 340 DEGs in testis/epididymis, testis/ductus deferens, and epididymis/ductus deferens comparisons, respectively. The expression of selected genes was validated using quantitative real-time reverse transcriptase-polymerase chain reaction. Bioinformatics analysis revealed several potential candidate genes involved in spermatogenesis, spermiogenesis and flagellum formation in the testis, and in post-testicular sperm maturation in the epididymis and ductus deferens. In the testis, genes were linked with the mitotic proliferation of spermatogonia and the meiotic division of spermatocytes. Histone ubiquitination and protamine phosphorylation were shown to be regulatory mechanisms for nuclear condensation during spermiogenesis. The characterization of testicular transcripts allowed a better understanding of acrosome formation and development and flagellum formation, including axoneme structures and functions. Spermatozoa motility during post-testicular maturation was linked to the development of flagellar actin filaments and biochemical processes, including Ca2+ influx and protein phosphorylation/dephosphorylation. Spermatozoa quality appeared to be controlled by apoptosis and antioxidant systems in the epididymis and ductus deferens. Finally, genes associated with reproductive system development and morphogenesis were identified. To the best of our knowledge, this is the first genome-wide functional investigation of genes associated with tissue-specific processes in turkey reproductive tract. A catalog of genes worthy of further studies to understand the avian reproductive physiology and regulation was provided.

The aim of this study was to determine the molecular mechanism of miR-205b targeting 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1) on the apoptosis and proliferation of granulosa cells (GC) of pigeons. Our previous studies suggested that HSD11B1 was the target gene of miR-205b and played a key role in steroid hormone biosynthesis and GC development. The adenovirus-miR-205b recombinant virus and adenovirus-cli-miR-205b-sh recombinant virus were generated, verified, and their characteristics determined. The recombinant viruses were used to infect the GC of pigeons, with real time quantitative PCR used to examine the expressions of HSD11B1 and related genes. The HSD11B1 antibody was obtained and verified, and Western blotting was used to detect the protein level of HSD11B1. The Cell Counting Kit–8 assay kit was used to detect cell viability, and the Annexin V-FITC/PI kit was used for the apoptosis assays. The expression of HSD11B1 was significantly lower in the overexpression (OE) than in OE negative control (OE-NC) treatments and significantly higher in short hairpin (SH) than in SH negative control (SH-NC) treatments. The expression levels of cytochrome P4503A5 was significantly higher in SH and lower in OE treatments, and the rhythms of cytochrome P450 aromatase mRNA levels were similar. The mRNA level of cytochrome P450scc in OE was lower than in OE-NC treatments and higher in SH than in SH-NC treatments. The protein expressions of HSD11B1 were decreased in the GC of OE, whereas increased in the SH group. The Cell Counting Kit–8 assay revealed that overexpression of miR-205b significantly suppressed proliferation of the GC of pigeons, whereas interference of miR-205b significantly induced the proliferation of the GC. The overexpression and the interference of miR-205b did not have a significant effect on cell cycle. The overexpression of miR-205b significantly increased the number of apoptotic cells, whereas the interference of miR-205b decreased the number of apoptotic cells. These findings indicated that miR-205b mediated pigeon egg production by regulating the steroid hormone biosynthesis of the pigeon ovarian GC by targeting HSD11B1, which may be useful in increasing pigeon egg production.

Egg yolk is an important source of nutrients for embryo development. In this study, the egg yolk protein composition at 0, 10, and 18 D of incubation was analyzed by 2-dimensional gel electrophoresis (2-DE) combined with matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. A significant difference in the abundance of 42 protein spots representing 12 proteins were identified (P < 0.05). The 2-DE gel image analysis exhibited that the molecular weight (MW) of 29 protein spots was lower than their theoretical value, in which 14 vitellogenin (VTG) fragments were lower than the theoretical value. There were 13 protein spots showed a higher MW including 5 ovotransferrins with MW of 87.2 kDa. The gene ontology enrichment analysis suggested that biological process of the differentially expressed proteins were mainly involved in lipid transport and lipid localization at 10 and 18 D of incubation. The molecular function of the differentially expressed proteins was involved in nutrient reservoir activity, lipid transporter activity, and antigen binding at 10 D of incubation. At 18 D of incubation, the differentially expressed proteins mainly participated in nutrient reservoir activity and substrate-specific transporter activity. The high abundance of VTGs at 10 D of incubation might participate in lipid localization and lipid transportation to facilitate the yolk nutrient transport to embryo. The low expression of ovotransferrins at 10 D of incubation indicated the chondrogenesis of embryo.

Florfenicol (FLO) is one of the most popular antibacterial drugs used in veterinary clinics and aquaculture. The drug was found to decrease the hatchability of eggs laid by treated hens in veterinary clinics and research work. However, the pathological changes in developing embryos and their cardiovascular system and the mechanism underlying FLO-induced embryonic death remain unclear. In the present study, fertilized eggs laid by hens treated with a therapeutic dose of FLO were collected and incubated. Results showed that FLO exposure repressed embryonic development and induced early embryonic death. As a result, FLO decreased the hatchability and increased the proportion of weak chicks. Moreover, FLO exposure led to embryonic lethality and inhibited the development of chick embryos as characterized by decreased weights, lagging distribution of Hamburger–Hamilton stages, and dysplastic eyes. Pathological examination indicated that FLO exposure affected the normal development of the heart in 4.5-day-old chick embryos, as characterized by shorter transverse cardiac diameter, disordered arrangement of trabecular muscles in ventricles, and reduced thickness of ventricular walls. Furthermore, FLO decreased blood vascular densities and downregulated the expression levels of key angiogenesis-related genes, including the vascular endothelial growth factor and fibroblast growth factor, in the yolk sac membrane. These findings indicated that FLO exposure restricted vascular development during early embryonic development. In summary, our data suggest that the restricted growth and abnormal cardiovascular development may be responsible for FLO-induced early embryonic death. Thus, these findings can be useful for guiding the proper use of FLO and in laying a foundation for further studies on the mechanism of FLO-induced embryonic toxicity.

The present study investigated the changes in morphology, enzyme activities in the pancreas and mucosa, and nutrient transporter gene expression in the duodenum and jejunum in male and female pigeons during the incubation and chick-rearing periods. Forty-two pairs of White King pigeons with 2 fertile eggs per pair were randomly divided into 7 groups by different breeding stages. The crypt depth of the duodenum and jejunum reached the peak at day 1 (R1) and day 7 (R7) of chick rearing, respectively. The jejunum surface area increased to a maximum value at R1. Amylase activity in the pancreas decreased to the lowest value at R1, whereas trypsin and lipase activities peaked at 17 D of incubation (I17) and R7, respectively. In male pigeons, mucosal Na+-K+-ATPase activity in the duodenum and jejunum was the highest at R15 and it was at I17 in female pigeons. Jejunum sucrose activity in female pigeons was higher at I4 than that at I17 (P

In this study, the aim was to investigate effects of chronic heat stress (CHS) on the mRNA levels of proinflammatory cytokines (interleukin [IL]-6, IL-8, IL-1β, and tumor necrosis factor alpha [TNF-α]), toll-like receptors (TLR2 and TLR4), heat shock proteins (Hsp70, heat shock transcription factor [HSF]-1, and HSF3) and antioxidant enzymes (catalase, glutathione peroxidase, NADPH oxidase, and superoxide-dismutase) in the jejunal mucosae of broiler chickens subjected to thermal manipulation (TM) during embryogenesis. TM was carried out at 39°C and 65% relative humidity (RH) for 18 h daily from embryonic days 10 to 18. Control group was incubated at 37.8°C and 56% RH. CHS was induced by raising the temperature to 35°C for 7 D throughout posthatch days 28 to 35. On post-hatch-day 28 (day zero of CHS) and after 1, 3, 5, and 7 D of CHS, the jejunal mucosae were collected from both groups to evaluate the mRNA levels by real-time reverse transcription-PCR analysis. On day zero of CHS, the mRNA levels of antioxidant enzymes, TLRs, HSF3, IL-1β, and TNF-α were not significantly different between TM and control groups, while the levels of IL-6, IL-8, and HSF1 were lower and the level of Hsp70 was higher in TM. However, during CHS, the mRNA levels of antioxidant enzymes, IL-1β, TNF-α, TLR4, and HSF1 were significantly lower in TM than in controls, while the levels of TLR2 and IL-8 were significantly higher in TM than in controls. In addition, TM led to significant increase of mRNA levels of IL-6 and HSF3 after 1 D and Hsp70 after 3 D of CHS and to significant decrease of mRNA levels of IL-6 after 3 and 5 D, HSF3 after 7 D, and Hsp70 after 5 D of CHS. Results of this study suggest that TM led to altered posthatch antioxidant, immunological, and Hsp response to CHS in the jejunal mucosae of broiler chickens, probably indicating that TM may mitigate the adverse effects of CHS.

This study was conducted to evaluate the effect of curcumin on laying performance, egg quality, biochemical indicators, hormone levels, and immune activity in hens under heat stress. Hy-Line brown hens (280-day-old) were fed with 0, 100, 150, and 200 mg/kg of curcumin during a 42-D experiment. Compared with the control treatment, supplementation with 150 mg/kg of curcumin improved laying performance and egg quality by significantly increasing egg production, eggshell thickness, eggshell strength (P < 0.01), and albumen height (P < 0.05) while decreasing the feed-to-egg ratio. Antioxidant activity was improved by significantly increasing the activity of superoxide dismutase and glutathione peroxidase but decreasing malondialdehyde levels in serum (P < 0.05) and significantly increasing the levels of follicle-stimulating hormone, luteinizing hormone, estradiol, IgG, IgA, and complement C3 activity in serum (P

The effect of ME intake (MEI) on the reproductive system was evaluated. Ross 308 broiler breeder pullets (n = 140) were assigned to 2 treatments from 22 to 26 wk of age: (1) Low-energy diet fed restricted (2,807 kcal/kg, low MEI) and (2) high-energy diet fed unrestricted (3,109 kcal/kg, high MEI). Daylength was increased from 8 to 14 h at 22 wk of age with a light intensity of 30 lux. Daily palpation was used to detect sexual maturity via the presence of a hard-shelled egg in the shell gland. Expression of gonadotropin releasing hormone-I (GnRH) and gonadotropin inhibitory hormone (GnIH) genes in the hypothalamus and GnRH receptor (GnRH-RI) and GnIH receptor (GnIH-R) genes in the anterior pituitary gland of each pullet was evaluated from 22 to 26 wk of age using quantitative real time-PCR. Blood samples were taken weekly and luteinizing hormone (LH), follicle stimulating-hormone (FSH), and 17-beta-estradiol (E2) determined using commercial ELISA kits. Carcass samples were used for determination of CP and fat content. Data were analyzed using the MIXED procedure in SAS, and differences were reported where P ≤ 0.05. High MEI treatment pullets had 2.3-fold higher GnRH and 1.8-fold higher GnRH-RI mRNA levels than low MEI pullets. MEI affected neither expression of GnIH and GnIH-R nor carcass protein content. For high MEI (489 kcal/D) and low MEI treatments (258 kcal/D), respectively, from 22 to 26 wk of age (P ≤ 0.05), LH concentration was 3.05 and 1.60 ng/mL; FSH concentration was 145 and 89.3 pg/mL; E2 concentration was 429 and 266 pg/mL, and carcass lipid was 13.9 and 10.3%. The onset of lay for pullets in the high MEI treatment advanced such that 100% had laid by 26 wk of age compared with 30% in the low MEI treatment. We concluded that higher MEI advanced the activation of the hypothalamic–pituitary–gonadal axis and also increased body lipid deposition, and moreover, stimulated reproductive hormone levels which overall accelerated puberty in broiler breeder pullets.