Eggs are a highly nutritious food and an excellent source of carotenoids, lutein and zeaxanthin, which contribute to antioxidant defenses and ocular health. However, eggs have been viewed skeptically because of their impact on serum cholesterol levels. This review summarizes the evidence from clinical trials, observational studies, and worldwide ecological studies relating egg consumption to serum lipid profiles, antioxidant status, and cardiovascular outcomes. Recent meta-analyses on egg consumption have reported an increase in serum cholesterol but limited or no impact on atherosclerosis and cardiovascular disease risk. Clinical studies have reported that the additional consumption of an egg per day for 4 weeks improved high-density lipoprotein-cholesterol levels and decreased oxidized low-density lipoprotein levels. Most recently, a cross-sectional study of Japanese patients who underwent coronary angiography reported no significant association between egg intake and the prevalence of coronary artery disease or multi-vessel disease. Among patients not receiving lipid-lowering drugs, moderate egg intake (3–4 eggs/week) was associated with a lower prevalence of multi-vessel disease. Furthermore, worldwide ecological analyses have identified a significant negative association between egg intake and the incidence and mortality of ischemic heart disease. Given their high nutritional value, relatively low cost, and the evidence presented, eggs could contribute to healthy diets in many countries worldwide.

In layer chicks, central administration of insulin and refeeding promote the phosphorylation of AKT and extracellular signal-regulated kinase (ERK) in the medulla oblongata. Broiler chicks consume more feed than layer chicks, suggesting distinct feeding regulation. This study aimed to clarify the involvement of medullary AKT and mitogen-activated kinases (MAPKs: ERK, c-Jun N-terminal kinase (JNK), and p38 MAPK) in regulating feeding of broiler chickens. The phosphorylation of AKT and p38 MAPK, but not that of ERK and JNK, was significantly higher in the medulla oblongata of broilers refed for 1 h after a 24-h fasting. Intracerebroventricular (ICV) administration of insulin significantly enhanced AKT phosphorylation in the medulla oblongata, but had no significant effect on the phosphorylation of MAPKs. Oral administration of glucose increased plasma glucose and the phosphorylation of AKT and p38 MAPK, but not ERK and JNK, in the medulla oblongata. ICV administration of the p38 MAPK activator anisomycin strongly induced the phosphorylation of p38 MAPK, but not JNK, without affecting feed intake. These findings suggest that medullary AKT contributes to insulin-induced suppression of feed intake in broiler chicks, while medullary p38 MAPK is phosphorylated in response to postprandial elevation of blood glucose, but is not involved in feeding regulation.

When facing dehydration, birds use body fat and proteins as a source of endogenous water. Recently, we found that osmotic stress triggered protein catabolism in skeletal muscles of chicks. In the present study, we investigated whether osmotic stress also affected fat metabolism. Twelve 21-day-old male chicks were allocated to two groups based on body weight. The chicks received either saline (0.15 M NaCl) or hypertonic saline (1.5 M NaCl) intraperitoneally (5 mL/kg body weight). After 1 h of feed and water deprivation, the chicks were euthanized by decapitation. Blood, breast muscle (pectoralis major), abdominal adipose tissue, liver, and kidney samples were collected, followed by analysis of plasma components and gene expression. Hypertonic saline significantly increased the plasma levels of non-esterified fatty acids (NEFA); adipose triglyceride lipase (ATGL) mRNA in adipose tissue; pyruvate dehydrogenase kinase 4 (PDK4) mRNA in breast muscle, adipose tissue, and liver; phosphoenolpyruvate carboxykinase 1 mRNA in the liver; and atrogin-1 mRNA in breast muscle. It also increased the plasma content of the hormone vasotocin. Subsequent intravascular administration of vasotocin significantly elevated plasma NEFA, but not ATGL or PDK4 mRNA in adipose tissue. Collectively, our findings suggest that osmotic stress alters nutrient metabolism in the peripheral tissues of chicks and that vasotocin may be partly involved in fatty acid mobilization.

Inflammation often accompanies the development of liver diseases in humans, but appears to be repressed in geese. This study investigated the role of MAP3K7 C-terminal-like (MAP3K7CL) in goose fatty liver formation. Sixteen healthy 70-day-old male geese were randomly divided into control and overfed groups. Additionally, the transcriptome analysis after MAP3K7CL overexpression and lipopolysaccharide (LPS) treatment were performed in goose primary hepatocytes. The results showed that the MAP3K7CL mRNA expression was increased in the liver of overfed treatment compared to control group. Overexpression of MAP3K7CL in primary goose hepatocytes identified differentially expressed genes enriched in the mitogen-activated protein kinase (MAPK) signaling pathway. Specifically, DNA damage-inducible transcript 3 (DDIT3), insulin-like growth factor 1 receptor (IGF1R), neurofibromin 1 (NF1), and platelet-derived growth factor subunit B (PDGFB) were significantly downregulated upon MAP3K7CL overexpression, whereas heat shock protein family B member 1 (HSPB1) was significantly upregulated. Furthermore, transfection of goose hepatocytes with the MAP3K7CL overexpression vector lowered the expression of lipopolysaccharide-induced TNF factor (LITAF) and cysteinyl aspartate-specific proteinase-3, which are associated with inflammation and apoptosis, respectively. In accordance with these findings, DDIT3 and LITAF were downregulated in the overfed group, whereas HSPB1 was upregulated. Compared with the control, LPS treatment significantly decreased MAP3K7CL expression, while promoting that of LITAF and interleukin-6 (IL-6). Moreover, the combination of lipopolysaccharide and MAP3K7CL overexpression upregulated MAP3K7CL while downregulating LITAF and IL-6 with respect to LPS alone and empty vector control groups. Therefore, MAP3K7CL may inhibit the inflammatory response in goose fatty liver.

Abstract: Insects are commanding increasing attention as a sustainable and alternative nutritional source in animal feed. In this study, the safety and nutritional profile of the dampwood termite, Hodotermopsis sjostedti, were evaluated as a novel ingredient in chicken feed. Colonies were lab-reared, and individual termites were collected by carefully crushing the wood, freeze-drying, and grinding. The resulting termite meal contained 65.6% crude protein, 16.0% fat, and 5.2% ash, on a dry matter basis. No minerals were present at toxic concentrations. Two feeding experiments using Ross 308 female broilers were conducted to evaluate the effects of termite meal inclusion. In Experiment 1, 20 chickens (8-d-old) were assigned to four treatments consisting of a commercial diet plus: 5.0% fish meal, 4.5% fish meal + 0.5% termite meal, 2.5% fish meal + 2.5% termite meal, and 5.0% termite meal. In Experiment 2, 18 chickens (9-d-old) were assigned to three diets: control, control + 2.5% termite meal, and control + 2.5% fish meal. Body weight and feed intake were recorded daily, and samples were collected at 21 d of age. Growth performances, organ weights, and blood plasma profiles were generally comparable across treatments. Chickens receiving 5.0% termite meal had greater alanine aminotransferase values, suggesting a potential hepatic burden. No adverse effects on growth, meat, or organ weight were observed. In conclusion, H. sjostedti meal demonstrated strong potential as a novel dietary component for broiler chickens. However, further long-term studies with larger numbers of birds are necessary to ensure a safe and effective use in poultry diets.

This study aimed to enhance meat quality and intestinal health of white-feathered broilers by utilizing methyl salicylate (MS), a fragrant plant-derived essential oil, for its anti-inflammatory, antibacterial, and antiplatelet properties. Specifically, we investigated the effects of dietary MS supplementation on the growth performance, carcass characteristics, intestinal morphology, and blood biochemistry and breast meat quality. A total of 270 one-day-old white-feather broilers were randomly assigned to three dietary treatments: a basal diet (CON), a basal diet supplemented with methyl salicylate at a low dosage of 0.25 g/kg (MSL), or at high dosage of 0.5 g/kg (MSH). Dietary MS treatment did not significantly affect the growth performance of broilers. However, dietary methyl salicylate supplementation significantly increased the blood levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (Tchol), and total antioxidant capacity (T-AOC) (P < 0.05). High-dose methyl salicylate supplementation also increased villus height in the jejunum (P < 0.05). Furthermore, methyl salicylate supplementation improved the a* value (redness) of breast muscle (P < 0.05). Additionally, the addition of methyl salicylate supplementation significantly retarded the increase in thiobarbituric acid (TBA) and total volatile basic nitrogen (TVB-N) levels in breast muscle (P < 0.05), potentially benefiting long-term meat preservation. Moreover, methyl salicylate increased the content of monounsaturated fatty acids in breast meat (P < 0.05). Consequently, our findings indicate that dietary supplementation with MS enhances meat quality and may extend the shelf life of white-feathered broilers by improving blood lipid parameters and modifying muscle fatty acid profiles.

Wooden Breast is a myopathy affecting broiler chickens, characterized by hardening of the pectoral muscle, fibrosis, adipogenesis, and deteriorated meat quality. This study investigated the pathological mechanisms underlying wooden breast development, focusing on the interplay between fibrogenesis and myogenesis. Seventy-eight broiler chickens were categorized into normal, mild, and severe wooden breast groups based on the extent of fibrosis and adipogenesis in the pectoral muscle. Histological analysis revealed immature collagen fibers within muscle fascicles in severe wooden breast, indicating concurrent fibrogenesis and muscle regeneration. Immunofluorescence staining confirmed the close spatial localization of fibro-adipogenic progenitors (FAPs) and myosatellite cells in these areas, suggesting potential interaction during wooden breast pathogenesis. RNA sequencing and qPCR revealed upregulation of PAX7 and MYOG, markers of myogenesis, in the affected pectoral muscle, whereas MYOD expression remained unchanged. This pattern indicates an attempt at myogenic differentiation that is ultimately disrupted in severe wooden breast samples. Furthermore, cellular communication network (CCN) family members, particularly CCN2 and CCN4, were upregulated in the wooden breast-affected pectoral muscle. CCN4 expression strongly correlated with the fibro-adipogenic progenitor marker PDGFRα, implying that fibro-adipogenic progenitors-mediated CCN4 secretion contributes to wooden breast pathogenesis. Our findings suggest that fibro-adipogenic progenitors and cellular communication network family members are associated with an imbalance between fibrogenesis and myogenesis, leading to the muscle degeneration observed in wooden breast.

Cisplatin is an anti-cancer drug that causes nausea and vomiting as adverse effects. Cisplatin-induced responses have been widely used to investigate the mechanisms underlying nausea and vomiting in several mammalian species. Because nausea and vomiting are caused by a variety of factors, including disease and stress, clarification of these mechanisms would contribute to improving animal welfare in poultry production. However, the effects of cisplatin in chickens have not been well documented. Thus, we examined whether intraperitoneal (IP) injection of cisplatin caused nausea and vomiting in chicks. IP injection of cisplatin decreased food intake, voluntary activity, and the passage of food from the crop. Moreover, cisplatin tended to increase plasma corticosterone concentrations and decreased plasma glucose concentration. As these effects are consistent with nausea-related responses observed in mammals, cisplatin might also induce nausea in chicks. However, cisplatin did not induce vomiting in any experiments. Furthermore, cisplatin slightly decreased the pH of the crop contents and phenol red gavaged into the proventriculus refluxed into the crop, although these effects were not considerable. Thus, the lack of substantial reflux from the proventriculus prevented vomiting in chicks after cisplatin injection.

As with other locally adapted species, Philippine mallard ducks risk population fragmentation and indiscriminate hybridization. To allow for targeted breed improvement, this study aimed to unravel the maternal genetic relationships, phylogeny, and levels of genetic diversity in Philippine mallard ducks. We sequenced the mitochondrial DNA D-loop region of 118 ducks sampled from the Southern Leyte, Samar, and Cebu Provinces. Sequence data analysis revealed nine transition base substitutions and eight distinct haplotypes. Overall haplotypic diversity (Hd = 0.666 ± 0.038) exceeded that reported for Javanese ducks, but was comparable to that of Thai, Chinese, and Indian domestic duck populations. The matrilineal phylogenetic tree positioned all Philippine mallard ducks within the Old-World Haplogroup A. Specifically, they clustered into subhaplogroup A3 (75/118), together with domestic ducks from China and Southeast Asia; putative ancestral subhaplogroups A0 (6/118) and A1a (5/118) in a basal position, showing close genetic affinities with Eurasian wild mallards and Eastern spot-billed ducks; and subhaplogroup A1b (6/118), showing genetic relatedness to the Indian Runner duck. Notably, 26 individuals formed a distinct cluster corresponding to subhaplogroup A2, which appeared to be unique to this population. This study provides the first mitochondrial DNA D-loop-based genetic characterization of Philippine mallard ducks, placing this population within the broader Haplogroup A lineage and highlighting how its genetics was shaped by island biogeography. Collectively, these results establish the basis for future research on animal genetic resources and phenomics, supporting the sustainable management of mallard duck populations in the Philippines.

This study investigated the effects of Phellinus linteus-fermented wheat bran (FWB) on growth performance, intestinal morphology, and modulation of nuclear factor erythroid 2-related factor 2-antioxidant response element-associated gene expression in broilers during summer conditions. The fiber content and cellulolytic enzyme activity of wheat bran (WB) improved after fermentation. In addition, FWB had a significantly higher secondary metabolite content, such as crude polysaccharides, ergosterol, and crude triterpenoids. Moreover, FWB showed 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging and ferrous ion-chelating abilities. Three hundred 1-day-old broiler chickens (Ross 308) were assigned into five groups fed the control diet or the control diet replaced with 5% WB, 10% WB, 5% FWB or 10% FWB. Over the entire experimental period, broilers in the 5% FWB group had a significantly lower feed conversion ratio than that of broilers in the control group. Assessment of blood characteristics revealed that broilers fed FWB had significantly higher serum superoxide dismutase activity and reduced malondialdehyde production. Measurement of the expression of antioxidant-related genes and proinflammatory cytokines in broiler peripheral blood mononuclear cells showed that partially replacing FWB in broiler diets enhanced the expression of antioxidant-related genes and decreased the expression of proinflammatory cytokines. These results indicated that P. linteus increased the feed value of WB and improved the growth performance and antioxidant capacity of broiler chickens, suggesting its potential for application in broiler diets during summer conditions.

Oxidative stress is a major constraint on broiler health and productivity. Mitochondrial dysfunction and gut–liver axis disruption play pivotal roles in this process. The present study investigated whether dietary quercetagetin (QG) alleviated diquat (DQ)-induced oxidative stress in broiler chickens through modulation of PINK1/Parkin-mediated mitophagy and gut–liver axis homeostasis. A total of 144 1-day-old WOD168 broilers were randomly assigned to four treatments with six replicate cages of six birds per cage: control group (non-challenged, basal diet), DQ group (DQ-challenged, basal diet), D_QG group (DQ-challenged, basal diet with 20 mg/kg QG), and QG group (non-challenged, basal diet with 20 mg/kg QG). On day 35, the DQ and D_QG groups were intraperitoneally administered DQ (20 mg/kg body weight). Dietary QG significantly increased body weight and attenuated the loss in average daily gain induced by DQ, while reducing serum aspartate aminotransferase levels. DQ challenge impaired gut barrier function, as indicated by decreased villus height, villus height/crypt depth ratio, and mRNA expression of Claudin-1 and ZO-1 (P < 0.05), exacerbated hepatic lesions, and significantly altered cecal microbial diversity. QG supplementation significantly attenuated the drop in glutathione peroxidase activity and downregulated PINK1 and LC3-II in hepatic mitochondria. It also significantly increased complex I activity, mitochondrial DNA copy number, and adenosine triphosphate content, while decreasing DQ-induced reactive oxygen species. Collectively, these results indicate that dietary QG alleviates DQ-induced oxidative stress by preserving mitochondrial function, potentially modulating PINK1/Parkin-related mitophagy, enhancing intestinal barrier integrity, and modulating cecal microbial composition.

Lipid oxidation produces an unpleasant warmed-over flavor (WOF) in meat. In this study, the antioxidant peptide carnosine (Car) was added to minced chicken breast and thigh meat, and its effect on WOF, volatile compounds, and meat quality during refrigerated storage was assessed. Breast and thigh meat patties were supplemented with four levels of Car (0, 1.0, 2.5, and 15 mg/g meat) and stored under refrigerated conditions for 1, 3, and 7 days. After that, WOF, volatile components, and meat quality factors were analyzed. The sensory attribute ‘oxidized oil odor’, a WOF indicator, was affected by Car supplementation and was lowest in samples supplemented with Car at 15 mg/g meat (Car15). In addition, some volatile aldehydes and thiobarbituric acid reactive substances (TBARS) in cooked meat causing WOF were lowest in Car15. Instead, samples supplemented with Car at 1.0 or 2.5 mg/g meat did not show significant differences in WOF, volatiles, or TBARS compared to controls without Car supplementation. Other meat quality parameters, such as pH, increased in Car15 samples; whereas L* and cooking loss decreased. In summary, supplementation of chicken breast and thigh meat with 15 mg/g Car reduced WOF intensity through inhibition of lipid peroxidation and influenced multiple meat quality parameters.

Progeny from older breeder hens exhibit higher feed intake but less efficient nutrient utilization than those from younger breeders. Multi-enzyme supplementation (MES) can serve as a practical dietary intervention to address this challenge. This study aimed to assess the effect of broiler breeder hen age (BBA) and MES on growth performance, gastrointestinal tract traits, nutrient digestibility, and cecal microflora profile of broilers. A total of 780 one-day-old straight-run Ross 308 chicks were arranged in a 2 × 3 factorial design according to two breeder ages (39 or 60 weeks) and three types of diet: a basal diet (CNT), basal diet supplemented with a commercial multi-enzyme product (AVZ, or Avizyme 1500^®), and a laboratory-formulated multi-enzyme preparation (LTE). Each treatment group consisted of five replicates with 26 birds. No significant interaction was observed between BBA and MES for any of the studied variables. Neither MES nor BBA influenced any growth performance trait. However, from days 28 to 42, the offspring of older parents showed an increased feed intake (P < 0.05). On day 9, MES lowered pancreatic weight (P < 0.05), pancreatic amylase activity (P < 0.01), and sulfite-reducing anaerobic bacteria in the cecum compared to the CNT treatment. Additionally, on days 9 and 42, LTE supplementation reduced (P < 0.01) pancreatic lipase activity and improved (P < 0.05) the digestibility of ether extract. The present results indicate that, when diets are formulated to meet or approach the nutritional requirements, chickens may not derive substantial additional benefits from AVZ or LTE supplementation. This may explain the absence of the anticipated interaction between BBA and MES.

Marked increases in sleep deprivation and circadian rhythm disruption adversely affect human health and the quality of life. In particular, the expansion of nighttime lighting associated with a 24-h society and digital technology has promoted late-night activity in mothers and children. Studies have examined the effects of circadian disruption on brain development in chickens, which are diurnal animals with genomic similarities to humans; however, adult chickens lack post-hatching parental care, which limits their utility in analyses of parent–offspring interactions. In this study, we investigated the potential use of Bengalese finches (Lonchura striata domestica) as model animals for circadian rhythm and physiological research. Given that the small size of Bengalese finches makes it difficult to implant nanotags directly, we developed and fitted specialized garments containing nanotags. After one week under experimental light cycle conditions, rectal temperature and weight were measured, and the activity recorded by the nanotags was analyzed. The nanotag garments did not impede Bengalese finch flight nor did they influence body temperature, weight, or whole-blood glucose levels. Finches housed under a 12-h:12-h light–dark cycle exhibited minimal activity during the dark phase and increased activity after the lights were turned on, reaching peak levels above 40 counts. In contrast, finches housed under constant 24-h light exhibited relatively continuous activity levels of 5–20 counts, with no distinct resting phase. The results demonstrate that locomotor activity rhythms in Bengalese finches are strongly regulated by environmental lighting conditions, and that nanotag placement using specialized garments enables non-invasive physiological and behavioral monitoring. Overall, our findings support the use of Bengalese finches as a practical and effective model for circadian rhythm research to facilitate studies on physiological regulation, development, and future investigations into parent–offspring interactions.

Racer pigeons are renowned for their exceptional flying abilities, and Shiqi pigeons are meat pigeons prized for their tender and nutritious meat. This study investigated the physiological and metabolic differences between the two breeds under distinct breeding objectives by examining their feeding habits, carcass performance, meat quality, and intestinal development, thereby providing insights for pigeon breeding programs. Six racer and six Shiqi pigeons, each aged 28 d, were selected. They were fed a basal diet until 35 d of age, after which they were slaughtered for testing. Racer pigeons had substantially lower daily feed and pellet intake than Shiqi pigeons. There was no difference in the proportion of the major grains consumed. Slaughter traits, including live, carcass, semi-eviscerated weights, and weights of the spleen, gizzard, and bursa of Fabricius were substantially lower in racer pigeons. Racer pigeons had substantially higher pectoral muscle redness and yellowness at 45-min post-slaughter but lower pH values at 45 min and 24 h. Racer pigeons had substantially higher plasma GSH-Px activity and glucose concentrations. Racer pigeons had a higher pectoral muscle triglyceride (TG) content, greater duodenal weight and length, higher duodenal villus-to-lumen ratio, and elevated catalase (CAT) activity. However, they had a lower pectoral muscle GLU content and reduced jejunal weight and length. Compact racer pigeons are physiologically adapted for flight and are characterized by a strong antioxidant capacity and a well-developed duodenum. In contrast, the larger Shiqi pigeon, with a more developed jejunum and heavier pectoral muscles, was optimized for digestion and meat yield. These distinct profiles highlight the strong influence of genetic selection; the identified metrics offer valuable insights into targeted breed development.

Nausea and vomiting are induced by environmental distress and pain; understanding their etiology can improve animal welfare in modern farm operations. Oral administration of CuSO₄ induces nausea and vomiting in some mammalian species and in pigeons. Although oral administration of CuSO₄ induces retching in chicks, whether it causes true vomiting or nausea-like responses remains unknown. This study examined whether intraoral, intracrop, and intragastric administrations of CuSO₄ induced vomiting, retching, and nausea-like responses in chicks (Gallus gallus domesticus). Food intake, crop emptying rate, and voluntary activity were used as indices of nausea-like responses. CuSO₄ limited food intake, irrespective of the administration route, and markedly reduced the crop-emptying rate. Voluntary activity remained unaffected by intraoral administration, but decreased following intracrop and intragastric administrations. Four of the six chicks exhibited retching after intraoral administration of CuSO₄; whereas intracrop and intragastric administrations failed to elicit this behavior. Similarly, CuSO₄ failed to cause any vomiting. These findings indicate that CuSO₄ does not act as an emetic agent in chicks; rather it induces nausea-like responses. Route-dependent effects further suggest that exposure within the oral cavity is required for the excretion of CuSO₄, possibly serving as a protective behavioral mechanism to reject irritant compounds before they enter the lower gastrointestinal tract.

Breed selection is a key factor for small- and medium-scale poultry producers, particularly regarding the adaptability of birds to local conditions, their productive performance, and product quality. In this study, we evaluated the laying performance and egg quality among hens of three genetic origins (Canarian, Lohmann Dual, and Novogen BT), as well as post-laying carcass and meat characteristics. In addition, consumer panels were employed to undertake sensory evaluations of eggs and meat. Sixty hens fed a commercial diet were reared under traditional free-range conditions. The production of eggs was monitored from 20 to 74 weeks of age, after which, the hens were slaughtered for carcass and meat analyses. Growth trajectories of hens were assessed using the Gompertz equation, which revealed distinct patterns among the three genotypes. The Canarian breed was characterized by a later age at inflection (9.5 weeks) and reached a higher asymptotic weight (2.2 kg) than the Lohmann Dual (7.3 weeks; 1.5 kg) and Novogen BT (7.9 weeks; 1.7 kg) breeds. With respect to egg production, efficiency was lower in Canarian hens (feed conversion ratio > 8.2) than that in Lohmann Dual and Novogen BT hens (feed conversion ratio = 2.9–3.9), which is assumed to be associated with the brooding behavior of Canarian hens. Compared with the other assessed breeds, Canarian eggs were characterized by distinctive quality traits, including tinted shell coloration and higher redness (a*) and yellowness (b*) values. Similarly, the meat and skin of Canarian hens had higher yellowness (b*) values, indicating specific quality attributes. Sensory evaluation revealed comparable acceptability among the three breeds, although Canarian hens received higher scores for specific sensory attributes of meat, particularly aroma, juiciness, and greasiness. These findings highlight the potential of local breeds for dual-purpose production and their valorization in free-range systems at the end of the laying cycle.

Glyoxal (GO) and methylglyoxal (MGO) are highly reactive alpha-dicarbonyl compounds (α-DCs) generated through multiple pathways of glucose metabolism. Both GO and MGO are cytotoxic to mammalian cells, and are implicated in the pathogenesis of several diseases, including diabetes. In mammalian systems, MGO reduces myoblast viability, and inhibits their differentiation. Conversely, we previously demonstrated that GO and MGO do not induce cell death in chicken myoblasts; however, their effects on myoblasts differentiation remain unclear. Therefore, the aim of the present study was to investigate the effects of GO and MGO on cell differentiation in chicken embryonic myoblasts. First, we analyzed the temporal expression patterns of key myogenic regulatory factors, including paired box 7, myoblast determination protein 1, myogenin, and myomaker, during the differentiation of chicken embryonic myoblasts. Exposure to GO or MGO significantly decreased the mRNA levels of key myogenic regulatory factors. Furthermore, both α-DCs suppressed myoblast fusion, a process necessary for myotube formation. Collectively, these findings revealed that α-DCs suppress cell differentiation in chicken embryonic myoblasts.

The European meat pigeon is an economically important poultry species; however, the metabolic characteristics of its reproductive cycle remain poorly understood. This study investigated body weight, crop and ovarian development, and key metabolic indices in the plasma, liver, crop, and ovaries of male and female pigeons during incubation (days 0, 6, 12, and 18) and lactation (days 0, 7, 14, and 21). Pigeons displayed enhanced anabolism and weight gain during incubation, but intensified catabolism during lactation. Males markedly lost weight with slow recovery, whereas female weight declined early during lactation and gradually recovered. Plasma total cholesterol levels increased during incubation and subsequently decreased. Female triglyceride and glucose (GLU) levels initially decreased and then increased. Total antioxidant capacity and catalase activities were higher during incubation than during lactation, with significant sex-related differences. In females, hydrogen peroxide (H₂O₂) levels increased and were higher, whereas malondialdehyde (MDA) levels decreased. Male testosterone and female progesterone and estradiol levels increased during incubation and then decreased. Hepatic GLU levels increased during incubation and decreased during late lactation. Albumin levels showed an overall increasing trend. Hepatic total superoxide dismutase activity and MDA levels were low during incubation and increased during lactation. Hepatic H₂O₂ levels increased and then decreased in males, and showed the opposite trend in females. The crop developed rapidly during incubation, but regressed quickly during lactation, especially in females. Female ovaries and follicles developed slowly during incubation but grew rapidly during lactation. Overall, the incubation period of meat pigeons was characterized by anabolic dominance, crop development, low oxidative stress, and follicular stasis in females. The transition to lactation induced a shift toward catabolism, post-peak crop regression, heightened oxidative stress, rapid ovarian development, and more rapid body weight recovery in females compared with males.

From an animal welfare perspective, thirst avoidance is an important criterion for the poultry industry. Neuropeptide Y (NPY) and α−melanocyte-stimulating hormone (α-MSH) play critical roles in regulating food intake, which is closely related to water intake in mammals and chickens. This study aimed to clarify the role of appetite-regulating neuropeptides in controlling thirst in chicks. In Experiment 1, 7-day-old male chicks were allocated to two groups and deprived of water for 24 h. Chicks were intracerebroventricularly injected with saline or the peptide. Water intake was measured at 60 and 120 min after injection under feed-deprived conditions. α-MSH significantly suppressed thirst-induced water intake, whereas NPY exhibited no effect. In Experiment 2, 8-day-old male chicks were allocated to two groups and intracerebroventricularly injected with either saline or peptide under ad libitum drinking conditions. NPY significantly increased water intake, whereas α-MSH had no effect. In Experiment 3, 8-day-old male chicks were allocated to two groups and euthanized after 0 or 3 h of water deprivation. Diencephalon mRNA levels of NPY and proopiomelanocortin (the gene encoding α-MSH) were not affected by water deprivation. Our findings suggest that chick NPY and α-MSH function as thirst-inducing and thirst-quenching peptides, respectively. Both control water intake through post-translational regulation.

Glucose is the primary substrate for cellular energy production, and its blood concentration is tightly regulated. This study investigated the effect of glucose supplementation during the first three days post-hatching on growth performance and diencephalic melanocortin-related gene expression in Red Cornish (RC) and Yamanashi Oh-Shamo (OSH-Y) chicks. We observed that body weight and weight gain were significantly higher in RC than in OSH-Y chicks. Glucose administration reduced body weight and feed intake at three days of age although no differences persisted thereafter. Significant differences in the expression of agouti-related peptide, AMP-activated protein kinase α2, cholecystokinin A receptor, and insulin receptor genes were detected between the two breeds. Conversely, neuropeptide Y was significantly downregulated by glucose supplementation in both breeds. Melanocortin receptor subtypes 3, 4, and melanocortin receptor accessory protein 2 exhibited significant breed and treatment interactions, with higher expression detected in glucose-fed OSH-Y chicks. These findings indicate that newly hatched chicks possess a centrally mediated glucose-sensing system that transiently suppresses feed intake. The more pronounced response observed in OSH-Y chicks suggests heightened hypothalamic glucose sensitivity, possibly mediated by the activation of melanocortin receptor signaling.

This study aimed to evaluate the effects of 5-aminolevulinic acid (5-ALA) supplementation in broiler chickens infected with Eimeria tenella. To assess these effects, chickens supplemented with 20 ppm 5-ALA (5-ALA group) were compared with non-supplemented controls (control group). Sporulated E. tenella oocysts (2.0 × 10³ oocysts per animal) were administered orally to 2-week-old broiler chickens. Body weight was measured weekly, and fecal samples were collected daily from 4 to 15 days post-infection (dpi). Fecal oocyst shedding was quantified using the sucrose flotation method. Cecal tissues were collected at 5 dpi for histopathological analysis and lesion scoring. The animals in the 5-ALA group exhibited significantly greater weight gain and milder clinical signs than those in the control group. Fecal oocyst shedding was highest at 7 dpi in both groups; however, the 5-ALA group exhibited significantly lower oocyst output than the control group. The total number of fecal oocysts shed during the acute infection period was significantly lower in the 5-ALA group than in the control group. Histopathological analysis revealed that although both groups exhibited epithelial hyperplasia and E. tenella schizonts in the cecal submucosa, inflammatory cell infiltration, cecal tissue damage, and histological lesion scores were significantly lower in the 5-ALA group than in the control group. These results suggest that 5-ALA supplementation may mitigate the clinical, parasitological, and histological effects of E. tenella infection in broiler chickens.