Heat stress alters tricarboxylic acid (TCA) cycle metabolism in broiler chickens; however, quantitative changes in TCA cycle-related metabolites remain poorly understood. This study determined the effects of heat exposure on TCA cycle intermediate (citrate, isocitrate, α-ketoglutarate, succinate, fumarate, and malate) and orotate levels in the liver and breast muscle of broiler chickens. Twelve 14-day-old male broiler chickens were assigned to either a control group (25 ± 1 °C) or a cyclic high ambient temperature group (35 ± 1 °C for 8 h/day) and reared under these conditions for 4 days. Heat exposure increased liver levels of citrate, α-ketoglutarate, fumarate, and malate, while decreasing succinate and orotate. Heat exposure also decreased the mRNA expression of isocitrate dehydrogenase 3A (IDH3A) and oxoglutarate dehydrogenase, key TCA cycle regulatory enzymes, as well as dihydroorotate dehydrogenase and ubiquinol–cytochrome c reductase Rieske iron–sulfur protein 1 (UQCRFS1), which are involved in mitochondrial electron transport. Heat exposure increased breast muscle levels of succinate, fumarate, and malate, while reducing IDH3A and UQCRFS1 mRNA expression. These findings suggest that heat exposure impairs TCA cycle metabolism in broiler chickens, possibly by reducing the utilization of TCA cycle intermediates through impaired electron transfer in mitochondrial complex III.
Maintaining intestinal health during the late-laying period is important for sustaining feed efficiency and bird health. Plant-derived feed additives have been explored as alternatives to antibiotic growth promoters. This study evaluated the effects of dietary supplementation with the extracts of three Artemisia species, individually and in combination, on laying performance, antioxidant status, and intestinal barrier function in laying hens. A total of 720 62-week-old Jingfen No. 6 laying hens were assigned to eight dietary treatments, with six replicate cages per treatment and 15 hens per cage. The treatments included a basal diet and diets supplemented with single or combined aqueous extracts of Artemisia argyi, Artemisia ordosica, or Artemisia annua for eight weeks. Compared to the control group, hens receiving combined Artemisia extracts showed a reduced feed-to-egg ratio (P < 0.05). The combined treatments also improved jejunal morphology, as indicated by increased villus height and villus height-to-crypt depth ratio (P < 0.05). In addition, the supplemented groups exhibited enhanced antioxidant capacity and modulated intestinal immune-related indices, as reflected by higher total superoxide dismutase, Glutathione peroxidase, Total antioxidant capacity, and Secretory immunoglobulin A levels (P < 0.05). The combined extract supplementation reduced serum IL-1β and IL-6 levels and Diamine oxidase activity while increasing Claudin-1 expression compared with the control group (P < 0.05). Jejunal transcriptomic analysis suggested that lipid metabolism, retinol metabolism, and peroxisome proliferator-activated receptor (PPAR)-related pathways might be involved in the response to combined Artemisia supplementation. Overall, the combination of Artemisia argyi, Artemisia ordosica, and Artemisia annua extracts may improve antioxidant status and intestinal barrier function, thereby contributing to improved feed utilization under the present experimental conditions.
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.
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.
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.
