Circadian calcium feeding regime in laying hens related to zinc concentration, gene expression of circadian clock, calcium transporters and oxidative status

One Health: Circadian Medicine Benefits Both Non-human Animals and Humans Alike

Circadian biology's impact on human physical health and its role in disease development and progression is widely recognized. The forefront of circadian rhythm research now focuses on translational applications to clinical medicine, aiming to enhance disease diagnosis, prognosis, and treatment responses. However, the field of circadian medicine has predominantly concentrated on human healthcare, neglecting its potential for transformative applications in veterinary medicine, thereby overlooking opportunities to improve non-human animal health and welfare. This review consists of three main sections. The first section focuses on the translational potential of circadian medicine into current industry practices of agricultural animals, with a particular emphasis on horses, broiler chickens, and laying hens. The second section delves into the potential applications of circadian medicine in small animal veterinary care, primarily focusing on our companion animals, namely dogs and cats. The final section explores emerging frontiers in circadian medicine, encompassing aquaculture, veterinary hospital care, and non-human animal welfare and concludes with the integration of One Health principles. In summary, circadian medicine represents a highly promising field of medicine that holds the potential to significantly enhance the clinical care and overall health of all animals, extending its impact beyond human healthcare.

Manganese methionine hydroxy analog chelated affects growth performance, trace element deposition and expression of related transporters of broilers

The present study aimed to evaluate the effects of manganese methionine hydroxyl analog chelated (Mn-MHAC) as a manganese (Mn) source on growth performance and trace element deposition in broilers. A total of 432 Arbor Acres commercial female broilers were fed a basal corn-soybean diet containing Mn at 25.64 mg/kg diet for 10 d. They were then randomly assigned to 6 groups, including a control group (the basal diet), a Mn sulfate group (the basal diet supplemented with Mn at 100 mg/kg diet), and 4 Mn-MHAC groups (the basal diet supplemented with Mn-MHAC at 25, 50, 75 and 100 mg Mn/kg diet, respectively). The results showed that compared with the control group, groups supplemented with Mn-MHAC had a positive effect on BW (quadratic, P = 0.017) and ADG (quadratic, P = 0.017). Moreover, the Mn-MHAC (50 mg Mn/kg diet) group had significantly greater BW and ADG (P < 0.05) compared with the other Mn-MHAC groups. Trace element deposition results also showed that tibial Mn increased (linear or quadratic, P = 0.002 and 0.009, respectively) in groups fed diets with increased levels of Mn-MHAC. In contrast, Fe deposition decreased both in the heart (linear, P = 0.020) and tibia (P < 0.05). In addition, the Mn-MHAC supplement noticeably lowered serum Mn-SOD activity (linear or quadratic, P = 0.048 and 0.019, respectively). The relative mRNA levels of divalent metal transporter 1 (DMT1) (P = 0.024), ferroportin 1 (FPN1) (P = 0.049), and Cu transporter-1(CTR1) (P < 0.001) in the duodenum, as well as CTR1 in the jejunum and ileum (P = 0.040 and 0.011, respectively) were higher in the Mn-supplemented group than in the control group. Furthermore, the relative mRNA level of DMT1 in the jejunum and ileum of broilers in the Mn-MHAC group (50 mg Mn/kg diet) did not differ from those in the control group, but was lower than those in the Mn sulfate group (P < 0.05). In conclusion, Mn-MHAC dietary supplementation improved the growth performance and trace element deposition in broilers. From this study, we recommend the optimum Mn-MHAC level to meet the Mn requirement of broilers is 50 to 75 mg Mn/kg diet.

Circadian zinc feeding regime in laying hens related to laying performance, oxidation status, and interaction of zinc and calcium

This study investigated that circadian zinc (Zn) feeding regime affected laying performance, Zn and calcium (Ca) status, antioxidant capacity and gene expression of circadian clock, and Ca and Zn transporter in laying hens. In total, 162 of 21-wk Hyline Sophie laying hens were assigned randomly into 3 groups including CON group (Control Zn, basal diets supplemented 60 mg/kg Zn), HL group (high-low Zn, basal diets supplemented 120 mg/kg Zn—basal diets), and LH group (low-high Zn, basal diets—basal diets supplemented 120 mg/kg Zn), which were fed at 0,530 h and 1,530 h, respectively. Blood, tibia, duodenum, and eggshell gland samples were collected at 8 h intervals with starting at 0,000 h in 1 d after 10 wk of experiment. Compared with CON group: 1) Feed conversion ratio (FCR) of LH and HL group decreased significantly (P < 0.05); 2) in serum, total antioxidant capacity and CuZn-superoxide dismutase (SOD) at 0,000 h increased significantly, as well as Ca and Zn concentration of tibia at 0,800 h in LH group (P < 0.05); 3) in duodenum, mRNA expression of calbindin-d28k (CaBP) and NCX1 at 1,600 h in HL group upregulated significantly, as well as Per2 and Per3 at 0,000 h, CLOCK, Cry2, Per2, and Per3 at 1,600 h (P < 0.05). But, Zn5 at 0,800 h in HL group downregulated significantly (P < 0.05). 4) In eggshell gland, the mRNA expression of CaBP at 0,000 h and Zn5 at 1,600 h in HL group downregulated significantly (P < 0.05). However, SOD at 1,600 h in HL group upregulated significantly, as well as Cry1 and Per3 at 0,800 h in HL group upregulated significantly (P < 0.05). In conclusion, circadian Zn feeding diet regime was beneficial to improvement of FCR. The regulation of laying hens' circadian rhythms affected Zn and Ca transporter and interrelationship between Ca and Zn metabolism, also altered antioxidant capacity in present study. Therefore, circadian Zn feeding regime can be considered as a new method to improve laying performance in laying hens.

Diurnal Rhythm of Plasma Melatonin Concentration in the Domestic Turkey and Its Regulation by Light and Endogenous Oscillators

Simple Summary

Environmental light regulates a wide range of phenomena in almost all organisms on Earth. Daily and seasonal changes in the photoperiod duration are the most important factors controlling the secretion of melatonin (MLT), a pineal hormone that affects many physiological processes in birds. The results of previous studies on the effect of MLT on the productivity and health of poultry have been promising. However, there are very few studies on the daily profiles of plasma MLT concentrations in domestic birds; therefore, we decided to examine plasma MLT levels in 10-week-old domestic turkeys exposed to different light conditions. The results demonstrated that plasma MLT concentration in turkeys kept under a 12 h light: 12 h dark cycle showed a prominent diurnal rhythm. Night-time light exposure caused a rapid decrease in plasma MLT concentrations. The housing of turkeys in continuous dim red light revealed endogenously generated diurnal rhythm of MLT secretion. The rhythm of the plasma MLT level in a reversed cycle of 12 h dark: 12 h light adapted quickly to the new lighting condition.

Abstract

The aim of this study was to characterize the diurnal rhythm of plasma melatonin (MLT) concentration and its regulation by light and endogenous oscillators in 10-week-old domestic turkeys. Three experiments were performed to examine (i) the course of daily changes in plasma MLT concentration in turkeys kept under a 12 h light: 12 h dark (12L:12D) cycle; (ii) the influence of night-time light exposure lasting 0.5, 1, 2, or 3 h on the plasma MLT level; and (iii) the occurrence of circadian fluctuations in plasma MLT levels in birds kept under continuous dim red light and the ability of turkeys to adapt their pineal secretory activity to a reversed light-dark cycle (12D:12L). The plasma MLT concentration was measured with a direct radioimmunoassay. The plasma MLT concentration in turkeys kept under a 12L:12D cycle changed significantly in a daily rhythm. It was low during the photophase and increased stepwise after the onset of darkness to achieve the maximal level in the middle of the scotophase. Next, it decreased during the second half of the night. The difference between the lowest level of MLT and the highest level was approximately 18-fold. The exposure of turkeys to light during the scotophase caused a rapid, large decrease in plasma MLT concentration. The plasma MLT concentration decreased approximately 3- and 10-fold after 0.5 and 1 h of light exposure, respectively, and reached the day-time level after 2 h of exposure. In turkeys kept under continuous darkness, the plasma MLT level was approximately 2.5-fold higher at 02:00 h than at 14:00 h. In birds kept under 12D:12L, the plasma MLT level was significantly higher at 14:00 h than at 02:00 h. The results showed that plasma MLT concentrations in 10-week-old turkeys have a prominent diurnal rhythm, which is endogenously generated and strongly influenced by environmental light.

Interactions Between Different Selenium Compounds and Essential Trace Elements Involved in the Antioxidant System of Laying Hens

The purpose of this study was to investigate the interactions between different selenium (Se) compounds including sodium selenite (SS), selenium-enriched yeast (SY), and nano-selenium (NS) and various essential trace elements involved in the antioxidant systems, and to evaluate the effects on laying performance and egg quality. A total of 288 21-week-old Hyline Sophie hens were allotted to four dietary treatments: (1) basal diet without Se supplementation; (2) basal diet supplemented with 0.3 mg/kg Se of SS; (3) basal diet supplemented with 0.3 mg/kg Se of SY; (4) basal diet supplemented with 0.3 mg/kg Se of NS. Each treatment had eight replicates with nine hens per replicate. The trial lasted for 35 days. Results demonstrated that NS supplementation decreased the egg production (EP) and increased the feed conversion rate (FCR) and eggshell thickness and that SY changed the egg shape index (p < 0.05). Supplementation with three Se compounds significantly increased serum Se concentration and glutathione peroxidase (GSH-Px) activity in all treatment groups, as well as total superoxide dismutase (T-SOD) activity in the SY and NS groups. Yolk iron (Fe) and copper (Cu) concentrations in the NS group were also increased with Se supplementation. While the serum zinc (Zn) concentration decreased in the NS and SY groups, as well as the yolk manganese (Mn) concentration in the SY group. And the total antioxidant capability (T-AOC) of yolk with 3 days of storage in the SY and NS groups, malondialdehyde (MDA) value in the NS group, and the T-SOD activity and MDA value of yolk with 10 days of storage in the SY group also decreased. Thus, the source of Se compounds may influence the balance between Se and other trace elements including Zn, Mn, Fe, and Cu, which is important for proper antioxidant defense in blood and egg yolk of laying hens.

Integrative analysis of transcriptomic data related to the liver of laying hens: from physiological basics to newly identified functions

BACKGROUND

At sexual maturity, the liver of laying hens undergoes many metabolic changes to support vitellogenesis. In published transcriptomic approaches, hundreds of genes were reported to be overexpressed in laying hens and functional gene annotation using gene ontology tools have essentially revealed an enrichment in lipid and protein metabolisms. We reanalyzed some data from a previously published article comparing 38-week old versus 10-week old hens to give a more integrative view of the functions stimulated in the liver at sexual maturity and to move beyond current physiological knowledge. Functions were defined based on information available in Uniprot database and published literature.

RESULTS

Of the 516 genes previously shown to be overexpressed in the liver of laying hens, 475 were intracellular (1.23-50.72 fold changes), while only 36 were predicted to be secreted (1.35-66.93 fold changes) and 5 had no related information on their cellular location. Besides lipogenesis and protein metabolism, we demonstrated that the liver of laying hens overexpresses several clock genes (which supports the circadian control of liver metabolic functions) and was likely to be involved in a liver/brain/liver circuit (neurotransmitter transport), in thyroid and steroid hormones metabolisms. Many genes were associated with anatomical structure development, organ homeostasis but also regulation of blood pressure. As expected, several secreted proteins are incorporated in yolky follicles but we also evidenced that some proteins are likely participating in fertilization (ZP1, MFGE8, LINC00954, OVOCH1) and in thyroid hormone maturation (CPQ). We also proposed that secreted proteins (PHOSPHO1, FGF23, BMP7 but also vitamin-binding proteins) may contribute to the development of peripheral organs including the formation of medullar bones to provide labile calcium for eggshell formation. Thirteen genes are uniquely found in chicken/bird but not in human species, which strengthens that some of these genes may be specifically related to avian reproduction.

CONCLUSIONS

This study gives additional hypotheses on some molecular actors and mechanisms that are involved in basic physiological function of the liver at sexual maturity of hen. It also revealed some additional functions that accompany reproductive capacities of laying hens, and that are usually underestimated when using classical gene ontology approaches.