Effect of curcumin on laying performance, egg quality, endocrine hormones, and immune activity in heat-stressed hens

Mitigation of Deoxynivalenol (DON)- and Aflatoxin B1 (AFB1)-Induced Immune Dysfunction and Apoptosis in Mouse Spleen by Curcumin

In the context of the potential immunomodulatory properties of curcumin in counteracting the detrimental effects of concurrent exposure to Deoxynivalenol (DON) and Aflatoxin B1 (AFB1), a comprehensive 28-days trial was conducted utilizing 60 randomly allocated mice divided into four groups. Administration of curcumin at a dosage of 5 mg/kg body weight in conjunction with DON at 0.1 mg/kg and AFB1 at 0.01 mg/kg body weight was undertaken to assess its efficacy. Results indicated that curcumin intervention demonstrated mitigation of splenic structural damage, augmentation of serum immunoglobulin A (IgA) and immunoglobulin G (IgG) levels, elevation in T lymphocyte subset levels, and enhancement in the mRNA expression levels of pro-inflammatory cytokines TNF-α, IFN-γ, IL-2, and IL-6. Furthermore, curcumin exhibited a suppressive effect on apoptosis in mice, as evidenced by decreased activity of caspase-3 and caspase-9, reduced expression levels of pro-apoptotic markers Bax and Cytochrome-c (Cyt-c) at both the protein and mRNA levels, and the maintenance of a balanced expression ratio of mitochondrial apoptotic regulators Bax and Bcl-2. Collectively, these findings offer novel insights into the therapeutic promise of curcumin in mitigating immunosuppression and apoptotic events triggered by mycotoxin co-exposure.

Current View on Major Natural Compounds Endowed with Antibacterial and Antiviral Effects

Nowadays, infectious diseases of bacterial and viral origins represent a serious medical problem worldwide. In fact, the development of antibiotic resistance is responsible for the emergence of bacterial strains that are refractory even to new classes of antibiotics. Furthermore, the recent COVID-19 pandemic suggests that new viruses can emerge and spread all over the world. The increase in infectious diseases depends on multiple factors, including malnutrition, massive migration of population from developing to industrialized areas, and alteration of the human microbiota. Alternative treatments to conventional antibiotics and antiviral drugs have intensively been explored. In this regard, plants and marine organisms represent an immense source of products, such as polyphenols, alkaloids, lanthipeptides, and terpenoids, which possess antibacterial and antiviral activities. Their main mechanisms of action involve modifications of bacterial cell membranes, with the formation of pores, the release of cellular content, and the inhibition of bacterial adherence to host cells, as well as of the efflux pump. Natural antivirals can interfere with viral replication and spreading, protecting the host with the enhanced production of interferon. Of note, these antivirals are not free of side effects, and their administration to humans needs more research in terms of safety. Preclinical research with natural antibacterial and antiviral compounds confirms their effects against bacteria and viruses, but there are still only a few clinical trials. Therefore, their full exploitation and more intensive clinical studies represent the next steps to be pursued in this area of medicine.

Supplementation of the Combination of Quercetin and Vitamin E Alleviates the Effects of Heat Stress on the Uterine Function and Hormone Synthesis in Laying Hens

Chickens are sensitive to heat stress because their capacity to dissipate body heat is low. Hence, in chickens, excessive ambient temperature negatively influences their reproductive performance and health. Heat stress induces inflammation and oxidative stress, thereby rendering many reproductive organs dysfunctional. In this study, we evaluated the effects of the supplementation of dietary quercetin and vitamin E on the uterine function, eggshell quality via estrogen concentration, calcium metabolism, and antioxidant status of the uterus of laying hens under heat stress. The ambient temperature transformation was set at 34 ± 2 °C for 8 h/d (9:00 am-5:00 pm), which was followed by 22 °C to 28 °C for 16 h/d. Throughout the experiment, the relative humidity in the chicken's pen was at 50 to 65%. A total of 400 Tianfu breeder hens (120-days-old) were randomly divided into four dietary experimental groups, including basal diet (Control); basal diet + 0.4 g/kg quercetin; basal diet + 0.2 g/kg vitamin E; and basal diet + the combination of quercetin (0.4 g/kg) and vitamin E (0.2 g/kg). The results show that the combination of quercetin and vitamin E significantly increased the serum alkaline phosphatase levels and the antioxidant status of the uterus (p < 0.05). In addition, the combination of quercetin and vitamin E significantly increased the concentrations of serum estrogen and progesterone, as well as elevated the expression of hypothalamic gonadotropin-releasing hormone-1 and follicular cytochrome P450 family 19 subfamily A member-1 (p < 0.05). We also found that the calcium levels of the serum and uterus were significantly increased by the synergistic effects of quercetin and vitamin E (p < 0.05), and they also increased the expression of Ca2+-ATPase and the mRNA expression of calcium-binding-related genes in the uterus (p < 0.05). These results are consistent with the increased eggshell quality of the laying hens under heat stress. Further, the combination of quercetin and vitamin E significantly increased the uterine morphological characteristics, such as the height of the uterine mucosal fold and the length of the uterine mucosa villus of the heat-stressed laying hens. These results collectively improve the uterine function, serum and uterine calcium concentration, eggshell strength, and eggshell thickness (p < 0.05) in heat-stressed laying hens. Taken together, we demonstrated in the present study that supplementing the combination of dietary quercetin and vitamin E alleviated the effects of heat stress and improved calcium metabolism, hormone synthesis, and uterine function in the heat-stressed laying hens. Thus, the supplementation of the combination of quercetin and vitamin E alleviates oxidative stress in the eggshell gland of heat-stressed laying hens, thereby promoting calcium concentration in the serum and eggshell gland, etc., in laying hens. Hence, the combination of quercetin and vitamin E promotes the reproductive performance of the laying hens under heat stress and can also be used as a potent anti-stressor in laying hens.

Effect of Curcumin on Hepatic mRNA and lncRNA Co-Expression in Heat-Stressed Laying Hens

Heat stress is an important factor affecting poultry production; birds have a range of inflammatory reactions under high-temperature environments. Curcumin has anti-inflammatory and antioxidant effects. The purpose of this experiment was to investigate the effect of dietary curcumin supplementation on the liver transcriptome of laying hens under heat stress conditions. In the animal experiment, a total of 240 Hy-Line brown hens aged 280 days were divided randomly into four different experimental diets with four replicates, and each replicate consisted of 15 hens during a 42-D experiment. The ambient temperature was adjusted to 34 ± 2 °C for 8 h per day, transiting to a range of 22 °C to 28 °C for the remaining 16 h. In the previous study of our lab, it was found that supplemental 150 mg/kg curcumin can improve production performance, antioxidant enzyme activity, and immune function in laying hens under heat stress. To further investigate the regulatory mechanism of curcumin on heat stress-related genes, in total, six samples of three liver tissues from each of 0 mg/kg and 150 mg/kg curcumin test groups were collected for RNA-seq analysis. In the transcriptome analysis, we reported for the first time that the genes related to heat stress of mRNA, such as HSPA8, HSPH1, HSPA2, and DNAJA4, were co-expressed with lncRNA such as XLOC010450, XLOC037987, XLOC053511, XLOC061207, and XLOC100318, and all of these genes are shown to be down-regulated. These findings provide a scientific basis for the possible benefits of dietary curcumin addition in heat-stressed laying hens.

Unveiling the emerging role of curcumin to alleviate ochratoxin A-induced muscle toxicity in grass carp (Ctenopharyngodon idella): in vitro and in vivo studies

BACKGROUND

Ochratoxin A (OTA), a globally abundant and extremely hazardous pollutant, is a significant source of contamination in aquafeeds and is responsible for severe food pollution. The developmental toxicity of OTA and the potential relieving strategy of natural products remain unclear. This study screened the substance curcumin (Cur), which had the best effect in alleviating OTA inhibition of myoblast proliferation, from 96 natural products and investigated its effect and mechanism in reducing OTA myotoxicity in vivo and in vitro.

METHODS

A total of 720 healthy juvenile grass carp, with an initial average body weight of 11.06 ± 0.05 g, were randomly assigned into 4 groups: the control group (without OTA and Cur), 1.2 mg/kg OTA group, 400 mg/kg Cur group, and 1.2 mg/kg OTA + 400 mg/kg Cur group. Each treatment consisted of 3 replicates (180 fish) for 60 d.

RESULTS

Firstly, we cultured, purified, and identified myoblasts using the tissue block culture method. Through preliminary screening and re-screening of 96 substances, we examined cell proliferation-related indicators such as cell viability and ultimately found that Cur had the best effect. Secondly, Cur could alleviate OTA-inhibited myoblast differentiation and myofibrillar development-related proteins (MyoG and MYHC) in vivo and in vitro and improve the growth performance of grass carp. Then, Cur could also promote the expression of OTA-inhibited protein synthesis-related proteins (S6K1 and TOR), which was related to the activation of the AKT/TOR signaling pathway. Finally, Cur could downregulate the expression of OTA-enhanced protein degradation-related genes (murf1, foxo3a, and ub), which was related to the inhibition of the FoxO3a signaling pathway.

CONCLUSIONS

In summary, our data demonstrated the effectiveness of Cur in alleviating OTA myotoxicity in vivo and in vitro. This study confirms the rapidity, feasibility, and effectiveness of establishing a natural product screening method targeting myoblasts to alleviate fungal toxin toxicity.

Effects of puerarin as a feed additive on the laying performance, egg quality, endocrine hormones, antioxidant capacity, and intestinal morphology of aged laying hens

The aim of this study was to investigate the effects of puerarin (Pue), a phytoestrogen, on the production performance, egg quality, endocrine hormones, antioxidant capacity, and intestinal morphology in aged laying hens. A total of 180 Hy-Line Brown hens aged 480 d were randomly divided into 4 groups (n = 45 per group) and fed 0, 200, 400, and 800 mg/kg of Pue (Con, L-Pue, M-Pue, and H-Pue, respectively) during a 42-d experiment. Compared with the Con treatment, supplementation with H-Pue improved laying performance and egg quality by significantly increasing egg production, average egg weight, albumen height, yolk weight, and Haugh unit (P < 0.05) while decreasing the feed conversion ratio (P < 0.05). A diet supplemented with H-Pue significantly decreasing serum total triglycerides, total cholesterol, and low-density lipoprotein cholesterol, alanine aminotransferase (P < 0.05), and significantly increasing serum levels of follicle-stimulating hormone, luteinizing hormone and progesterone (P < 0.05). Antioxidant activity was improved by significantly increasing the activity of total antioxidant capacity, glutathione peroxidase and catalase but decreasing malondialdehyde levels in serum, jejunum, and ileum (P < 0.05), and superoxide dismutase activity exhibited a significantly increase in the jejunum and ileum (P < 0.05). Villus height and the ratio of villus height to crypt depth (P < 0.05) were significantly increased in the jejunum and ileum. In the jejunal and ileal mucosa, the three treatment groups increased the mRNA expression levels of Claudin-1 and Claudin-2 compared with Con (P < 0.05), and no significant effect was observed on the expression of Occludin and ZO-1. The results showed that dietary supplementation with Pue could improve the laying performance, egg quality, antioxidant capacity, hormonal profile, and intestinal morphology of aged laying hens.

Investigating bacteriophages as a novel multiple-hurdle measure against Campylobacter: field trials in commercial broiler plants

Campylobacter mitigation along the food production chain is considered effective for minimizing the public health burden of human campylobacteriosis. This study is the first combining different measures in a multiple-hurdle approach, using drinking water additives and feed additives in single and combined application schemes in commercial broiler plants. Broiler chickens in the study groups were naturally contaminated with Campylobacter. Application of an organic acid blend via drinking water, consisting of sodium propionate, potassium sorbate, and sodium diacetate, resulted in significant reductions of up to 4.9 log10 CFU/mL in fecal samples and in cecal samples at slaughter. The application of a phage mixture, consisting of Fletchervirus phage NCTC 12673 and Firehammervirus phage vB_CcM-LmqsCPL1/1, resulted in reductions of up to 1.1 log10 CFU/mL in fecal samples 1 day after dosing. The sole administration of curcumin via feed resulted in small and inconsistent reductions. In the group receiving a combination of all tested measures, reductions of up to 1.1 log10 CFU/mL were observed. Based on the results of our field trials, it was shown that both the sole application and the combined application of mitigation measures in primary production can reduce the Campylobacter load in broiler chickens, while no synergism could be observed.

Inhibition of pathogenic microbes in oral infectious diseases by natural products: Sources, mechanisms, and challenges

The maintenance of oral health is of utmost importance for an individual's holistic well-being and standard of living. Within the oral cavity, symbiotic microorganisms actively safeguard themselves against potential foreign diseases by upholding a multifaceted equilibrium. Nevertheless, the occurrence of an imbalance can give rise to a range of oral infectious ailments, such as dental caries, periodontitis, and oral candidiasis. Presently, clinical interventions encompass the physical elimination of pathogens and the administration of antibiotics to regulate bacterial and fungal infections. Given the limitations of various antimicrobial drugs frequently employed in dental practice, the rising incidence of oral inflammation, and the escalating bacterial resistance to antibiotics, it is imperative to explore alternative remedies that are dependable, efficacious, and affordable for the prevention and management of oral infectious ailments. There is an increasing interest in the creation of novel antimicrobial agents derived from natural sources, which possess attributes such as safety, cost-effectiveness, and minimal adverse effects. This review provides a comprehensive overview of the impact of natural products on the development and progression of oral infectious diseases. Specifically, these products exert their influences by mitigating dental biofilm formation, impeding the proliferation of oral pathogens, and hindering bacterial adhesion to tooth surfaces. The review also encompasses an examination of the various classes of natural products, their antimicrobial mechanisms, and their potential therapeutic applications and limitations in the context of oral infections. The insights garnered from this review can support the promising application of natural products as viable therapeutic options for managing oral infectious diseases.

Curcumin Mitigates Oxidative Damage in Broiler Liver and Ileum Caused by Aflatoxin B1-Contaminated Feed through Nrf2 Signaling Pathway

This experiment aimed to investigate the mitigating effect of CUR on the growth performance and liver and intestinal health of broilers fed AFB1-contaminated diets. In this study, 320 one-day-old healthy male Arbor Acres (AA) broilers were randomly divided into four groups, including the Control group (fed the basal diet), the AFB1 group (fed the AFB1-contaminated diet containing 1 mg/kg AFB1), the AFB1+CUR group (fed the AFB1-contaminated diet with 500 mg/kg CUR), and the CUR group (fed the basal diet containing 500 mg/kg CUR), with eight replicates of ten animals per group and a 28 d experimental period. In terms of the growth performance, the addition of 500 mg/kg CUR significantly improved AFB1-induced significant reductions in the final body weight on day 28 and mean daily gain (p < 0.05) and increased the ratio of the mean daily feed intake to mean daily weight gain in broilers (p < 0.05). In terms of liver health, significant improvements in liver histological lesions occurred in broilers in the AFB1+CUR group compared to the AFB1 group, with significantly higher glutathione peroxidase (GSH-Px), catalase (CAT), and total superoxide dismutase (T-SOD) activities (p < 0.05) and significantly higher levels of nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap-1), heme oxygenase 1 (HO-1), and NAD(P)H quinone oxidoreductase 1 (NQO-1) gene expression (p < 0.05). In terms of intestinal health, CUR addition significantly increased the relative length of ileum (p < 0.05), significantly elevated the height of ileal villi (p < 0.05), significantly reduced D-Lactate (D-LA) and diamine oxidase (DAO) activities in broiler serum (p < 0.05), significantly increased GSH, CAT, and T-SOD activities in ileal tissues (p < 0.05), and significantly elevated the expression of Nrf2, HO-1, and NQO-1 genes (p < 0.05) compared to the AFB1 group. In conclusion, CUR showed a protective effect against damage to the liver and intestine caused by AFB1 in broilers through the Nrf2 signaling pathway, thereby improving the growth performance of broilers exposed to AFB1.

Curcumin improves the egg quality, antioxidant activity, and intestinal microbiota of quails during the late laying period

This study aimed to investigate the effects of dietary curcumin supplementation on laying performance, egg quality, egg metabolites, lipid metabolism, antioxidant activity, and intestinal microbial composition of quails in the late laying period. A total of 960 late-laying quails (240-day-old) were randomly divided into 4 groups of 6 replicates each (n = 40/replicate). The experimental diets of the 4 groups consisted of basal diets supplemented with 0, 50, 100, and 200 mg/kg curcumin, respectively. The feeding experiment lasted for 8 wk. The results showed that 200 mg/kg curcumin supplementation decreased mortality and increased eggshell thickness and strength compared with the 0 mg/kg curcumin supplementation during wk 5 to 8. In addition, dietary supplementation of curcumin promoted lipid metabolism, enhanced antioxidant activity, and modified intestinal microbiota structure. In conclusion, dietary supplemented with 200 mg/kg curcumin significantly improved the egg quality of quails in the late laying period, primarily by improving lipid metabolism and selectively regulating the intestinal microbial community.

Effects of Curcumin on the Egg Quality and Hepatic Lipid Metabolism of Laying Hens

Curcumin, the major active compound of turmeric, has shown potential benefits for poultry health and production in various studies. However, its specific role in enhancing the egg quality and liver health of laying hens, as well as its underlying mechanisms, have yet to be determined. Here, a total of 600 Su Qin No.1 Laying hens, aged 55 weeks and with similar laying rates, were randomly placed into five groups, with 10 replicates of 12 hens each. Curcumin doses of 0, 100, 200, 400, and 800 mg/kg were added to the basal diet to form the experimental groups. After an 8-week feeding period, no significant changes were observed in the production performance of laying hens due to curcumin supplementation. However, additional tests revealed that a 200 mg/kg curcumin supplementation improved albumen height, yolk color, Haugh unit, and eggshell thickness, while reducing the thin albumen's weight and proportion. This was accompanied by a significant down-regulation of the mRNA expression level of the Prolactin Receptor (Prlr) in the oviduct magnum. Furthermore, the number of hepatic lipid droplets and the hepatic triglyceride (TG) content, as well as malondialdehyde (MDA) levels were significantly reduced, indicating improved hepatic lipid metabolism and oxidative status. This was accompanied by a significant reduction in the expressions of sterol regulatory element binding protein-1 gene (Srebp-1), fatty acid synthase gene (Fasn), as well as fatty acid synthase (FASN), which are closely related to fatty acid synthesis in the liver. Overall, these findings suggest that curcumin supplementation at a dosage of 200 mg/kg could lead to significant improvements in egg quality and hepatic lipid metabolism.

Turmeric (Curcuma longa): an alternative to antibiotics in poultry nutrition

Turmeric, a common spice in many countries has been used for centuries in traditional medicine for its antimicrobial properties. Recent research has shown that turmeric can be a viable alternative to antibiotics in poultry production. Antibiotic overuse in poultry has led to the development of antibiotic-resistant bacteria, which poses a threat to both animal and human health. Turmeric contains curcumin, a compound that has been shown to have antimicrobial activity against a wide range of bacteria, including those resistant to antibiotics. In addition, turmeric has anti-inflammatory and immunomodulatory properties, which can help boost the immune system of poultry and reduce the need for antibiotics. Studies have shown that turmeric can improve growth performance, and gut health, and reduce the incidence of disease in poultry. Therefore, the use of turmeric as an alternative to antibiotics in poultry production has the potential to not only improve animal health and welfare but also contribute to the fight against antibiotic resistance. This review aims to provide an overview of the recent knowledge on the use of these plant extracts in poultry feeds as feed additives and their effects on poultry performance.

Effects of dietary supplement with licorice and rutin mixture on production performance, egg quality, antioxidant capacity, and gut microbiota in quails (Turnix tanki)

This study was conducted to evaluate the effect of licorice and rutin on production performance, egg quality, and mucosa antioxidant levels in Chinese yellow quail. A total of 240 Chinese Yellow Quail (400-day-old) were randomly distributed into 5 groups: the Control group, fed with a basic diet; the LR1 group, fed with basal diet supplemented with 300 + 100 mg licorice and rutin mixture/kg diet; the LR2 group, fed with basal diet supplemented with 300 + 200 mg licorice and rutin mixture/kg diet; the LR3 group, fed with basal diet supplemented with 600 + 100 mg licorice and rutin mixture/kg diet and the LR4 group, fed with basal diet supplemented with 600 + 200 mg licorice and rutin mixture/kg diet. Compared with the control, supplementation with the licorice and rutin mixture improved the laying rate and eggshell thickness whereas decreased the feed conversion ratio of quails. Moreover, dietary supplementation with the licorice and rutin mixture improved the antioxidant capacity by increasing the activity of the superoxide dismutase (SOD) level and decreasing the concentration of malondialdehyde (MDA) in the jejunal mucosa. The licorice and rutin mixture altered the composition of intestinal microbiota by influencing the relative abundances of Bacteroidetes and Bacteroides. The relative abundances of the Bacteroidetes were significantly related to the laying rate of quails. In addition, the mixture of licorice and rutin was also effective in reducing the relative abundance of intestinal Proteobacteria and Enterobacter in quails, reducing the accumulation of antibiotic-resistance genes. The results revealed that supplementation of licorice and rutin mixture to the diet improved production performance, egg quality, and antioxidant capacity and modified the composition of intestinal microbiota in quails. This study provides a reference for Chinese herbal additives to promote production performance by modulating quail gut microbes.

The efficacy of polyphenols as an antioxidant agent: An updated review

Global production of the two major poultry products, meat and eggs, has increased quickly. This, in turn, indicates both the relatively low cost and the customers' desire for these secure and high-quality products. Natural feed additives have become increasingly popular to preserve and enhance the health and productivity of poultry and livestock. We consume a lot of polyphenols, which are a kind of micronutrient. These are phytochemicals with positive effects on cardiovascular, cognitive, anti-inflammatory, detoxifying, anti-tumor, anti-pathogen, a catalyst for growth, and immunomodulating functions, among extra health advantages. Furthermore, high quantities of polyphenols have unknown and occasionally unfavorable impacts on the digestive tract health, nutrient assimilation, the activity of digestive enzymes, vitamin and mineral assimilation, the performance of the laying hens, and the quality of the eggs. This review clarifies the numerous sources, categories, biological functions, potential limitations on usage, and effects of polyphenols on poultry performance, egg composition, exterior and interior quality traits.

Curcumin and curcumin nanoparticles counteract the biological and managemental stressors in poultry production: An updated review

Antibiotics have the potential to have both direct and indirect detrimental impacts on animal and human health. For instance, antibiotic residues and pathogenic resistance against the drug are very common in poultry because of antibiotics used in their feed. It is necessary to use natural feed additives as effective alternatives instead of synthetic antibiotics. Curcumin, a polyphenol compound one of the natural compounds from the rhizomes of turmeric (Curcuma spp.) and has been suggested to have several therapeutic benefits in the treatment of human diseases. Curcumin exhibited some positive responses such as growth promoter, antioxidant, antibacterial, antiviral, anticoccidial, anti-stress, and immune modulator activities. Curcumin played a pivotal role in regulating the structure of the intestinal microbiome for health promotion and the treatment of intestinal dysbiosis. It is suggested that curcumin alone or a combination with other feed additives could be a dietary strategy to improve poultry health and productivity.

A Method to Reduce the Occurrence of Egg Translucency and Its Effect on Bacterial Invasion

Translucent egg consumption is low due to consumer acceptance and quality concerns, which is a problem that egg producers need to address. This study was performed to evaluate the reasons for the high occurrence of egg translucency in summer, as well as whether the addition of mono-dicalcium phosphate (MDCP) to the diet can relieve eggshell translucency and whether eggshell translucency is associated with the risk of bacterial invasion. A total of 72 laying hens that were 36 weeks old were randomly divided into control (CON) and MDCP groups and fed in the same environment. Results showed that the number of translucent eggs increases in July and August as the temperature and humidity increase. Compared with the CON group, in July, August, and October, the translucent egg grade (TEG) of the MDCP group was lower than that of the CON group (p < 0.05). TEG was correlated with mastoid space height (MSH), width (MSW), and area (MSA) (correlation coefficients 0.63, 0.59, and 0.68, respectively, p ≤ 0.05). There was no significant difference in the invasion rate of E. coli between translucent and non-translucent egg groups (47.2% vs. 39.33%), and translucent area and non-translucent area (13.49% vs. 15.08%). In conclusion, our results show that dietary MDCP may alleviate eggshell translucency and that eggshell translucency would not increase the probability of E. coli cross-shell penetration rate.

Effect of Dietary Supplemental Zinc on Laying Performance, Egg Quality, and Plasma Hormone Levels of Breeding Pigeons

This study aimed to evaluate the dietary zinc requirement of parental pigeons for better laying and reproductive performance, egg quality, sex hormones, and mineral content in eggs. A total of 160 pairs of healthy American Silver King pigeons were randomly assigned to five treatments of eight replicate cages each with four pairs of birds per cage, and fed a basal diet without zinc supplementation or the basal diet supplemented with 30, 60, 90, and 120 mg of zinc/kg (ZnSO₄·7H₂O). The experiment lasted for 45 days, including two laying cycles. Results indicated the egg production rate (P = 0.081), egg shape index (P = 0.038), egg eggshell percentage (P = 0.070), and zinc and calcium contents (P < 0.01) tended to be affected or significantly affected by zinc addition. They increased quadratically with dietary zinc levels (P < 0.05). Besides, shell thickness (P = 0.069), plasma testosterone (P = 0.008), LH, and carbonic anhydrase contents (P < 0.05) tended to be affected or significantly affected by zinc addition. They increased linearly as dietary zinc level increased (P < 0.05). Compared with the control, 60 mg/kg zinc addition increased egg production rate, egg shape index, zinc and calcium contents in eggshell, and plasma testosterone concentration in pigeons (P < 0.05), and tended to increase the eggshell percentage (P = 0.07). Besides, supplemental 120 mg/kg zinc had higher shell thickness and LH content than control (P < 0.05), but had no difference with 60 mg/kg zinc addition. In conclusion, the supplementation of zinc at the level of 60 mg/kg to basal diet improved laying performance by increasing eggshell quality and sex hormone levels of breeding pigeons.

Antioxidant properties and cytotoxic effects of selected edible plants in Southeast Asia for further use as phytogenic antioxidant additives

Excessive free radicals in human and animal bodies can cause oxidative stress (OS) which damages cells and tissues. Plant materials with high antioxidant potential would resolve the OS problem. Thus, this study proposed to investigate the total phenolic (TPC) and flavonoid contents (TFC), antioxidant capacities and cytotoxicity in 17 edible plant materials from herbs, fruits, vegetables and plant by-products available in Southeast Asia for future use in the food or feed industry. Among 17 plant materials, Syzygium aromaticum (clove), Camellia sinensi (green tea pomace) from the beverage industry and Persicaria odorata (Vietnamese coriander) showed a prominent amount of TPC and TFC. These three plants and their combination (1:1:1 ratio, v:v:v) also possessed a remarkable antioxidant function in terms of DPPH, ABTS and FRAP, as well as showing a strong ROS inhibition through HepG2 cells. The cytotoxicity test of the crude extract of clove, green tea pomace and Vietnamese coriander, or their combination can be used between 0.032 and 0.255, 0.011 to 0.088, 0.022 to 0.178 and 0.021 to 0.346 mg/mL, respectively, without impeding cell viability. A combined mixture of clove, green tea pomace and Vietnamese coriander revealed the synergistic properties of antioxidants and cell safety. This indicates that there is a potential use of various antioxidant bioactive compounds in plant materials tested for use as phytogenic antioxidant additives.

The impact of curcumin on livestock and poultry animal's performance and management of insect pests

Plant-based natural products are alternative to antibiotics that can be employed as growth promoters in livestock and poultry production and attractive alternatives to synthetic chemical insecticides for insect pest management. Curcumin is a natural polyphenol compound from the rhizomes of turmeric (Curcuma spp.) and has been suggested to have a number of therapeutic benefits in the treatment of human diseases. It is also credited for its nutritional and pesticide properties improving livestock and poultry production performances and controlling insect pests. Recent studies reported that curcumin is an excellent feed additive contributing to poultry and livestock animal growth and disease resistance. Also, they detailed the curcumin's growth-inhibiting and insecticidal activity for reducing agricultural insect pests and insect vector-borne human diseases. This review aims to highlight the role of curcumin in increasing the growth and development of poultry and livestock animals and in controlling insect pests. We also discuss the challenges and knowledge gaps concerning curcumin use and commercialization as a feed additive and insect repellent.

Productive, physiological and nutritional responses of laying hens fed different dietary levels of turmeric powder

This study aimed to determine the impact of supplementation of turmeric powder on laying performance, egg quality, nutrient digestibility and some blood metabolites in laying hens. A total of one hundred and twenty Bovans Brown laying hens (55 weeks old) were assigned to one of four treatment diets (n = 30) for 12 weeks including turmeric powder at 0, 2.5, 5 or 7.5 g/kg respectively. The results revealed that egg production, egg weight and egg mass were significantly increased (p < 0.05), and the feed conversion ratio was significantly improved (p < 0.012) with increasing levels of turmeric in the laying hen diet. Egg thickness and Haugh unit were linearly increased (p < 0.01) with increasing supplementation levels. Moreover, compared with the control diet, the levels of turmeric powder supplementation significantly improved nutrient digestibility (p < 0.001). Moreover, the serum metabolic profile revealed that serum total cholesterol, aspartate aminotransferase, creatinine and urea concentrations were linearly decreased with increasing turmeric powder supplementation to hen diets. In conclusion, the inclusion of turmeric powder at 2.5, 5 or 7.5 g/kg diet improved egg production, nutrient digestibility, egg quality and serum metabolic profile and may be used as a feed additive in laying hens' nutrition. However, results indicate that the best improvement was observed when 5 g/kg were supplemented.

Dietary supplementation with chia polyphenols alleviates oxidative stress and improves egg nutritional quality in Japanese quails under heat stress

Heat stress in poultry is a major concern, especially in regions with hot summers and scarce cooling infrastructure. Dietary supplementation with antioxidants, such as polyphenols, has risen as a strategy to mitigate the physiological consequences of heat stress. A by-product of the extraction of oil from chia seeds, which is discarded if not used, could be a possible source of polyphenols. The aim of the present study was to evaluate the effects of dietary supplementation with polyphenols from defatted chia seed cake on the general performance, and oxidative status of Japanese quail exposed to heat stress. Furthermore, productive performance, egg quality and yolk fatty acid composition were also assessed. A total of 36 females (96 days of age) were randomly assigned to different diets: BASAL (control), LDCP (low dose of chia polyphenols), or HDCP (high dose of chia polyphenols). Half the animals in each diet group were exposed to 34 °C for 9 h a day (Heat Stress; HS), while the other half remained at the standard 24 °C (No Heat Stress; NHS). After 23 days of experimental conditions, animals under HS showed higher body temperatures and time spent panting, but lower egg laying rate. Moreover, HS modulated the activity of catalase and glutathione peroxidase enzymes, increasing lipid peroxidation in serum and liver; and increased saturated fatty acids in egg yolk. Supplementation with chia polyphenols helped to mitigate the HS effects, especially on glutathione peroxidase activity, decreasing lipid peroxidation. In addition, supplementation with HDCP showed the highest proportion of polyunsaturated fatty acids in liver and egg yolk. In conclusion, the use of defatted chia seed cake could represent a sustainable strategy to mitigate heat stress effects on Japanese quail, due to its capacity to decrease oxidative stress and improve the nutritional quality of egg, while decreasing the amount of waste generated by the food industry.

Current Development and Future Application Prospects of Plants-Derived Polyphenol Bioactive Substance Curcumin as a Novel Feed Additive in Livestock and Poultry

Curcumin (CUR) is a kind of natural orange-yellow phenolic compound mainly extracted from the stems and roots of turmeric plants and other species in the genus Curcuma, furthermore, it is also the most important active ingredient exerting pharmacological functions in turmeric. In recent years, CUR has been frequently reported and has attracted widespread attention from scholars all over the world due to its numerous biological functions and good application prospects, such as anti-inflammatory, anticancer, antioxidant and providing lipid-lowering effects, etc. In addition, adding a certain dose of CUR to livestock and poultry feed is important for animal growth and development, which plays a key role in animal metabolism, reproduction, immunity and clinical health care. This review aims to summarize, based on the published papers and our own observations, the physical and chemical properties and the biological functions of the plant-derived bioactive ingredient CUR, especially regarding the latest research progress in regulating intestinal health as well as its current development and future application prospects in livestock and poultry as a novel feed additive, so as to provide theoretical and practical references for the further study of the application of CUR as a novel feed additive and a potential new antibiotic substitute, thereby improving the research field of plant-derived bioactive ingredients and promoting the healthy development of livestock and poultry.

Dietary Phytogenic Extracts Favorably Influence Productivity, Egg Quality, Blood Constituents, Antioxidant and Immunological Parameters of Laying Hens: A Meta-Analysis

The present study aimed to assess the impact of dietary phytogenic extracts on laying hen productivity, egg quality, blood constituents, antioxidant, and immunological parameters through a meta-analytical approach. A total of 28 articles (119 data points) reporting the influence of dietary phytogenic extracts on the productive performance, egg quality, blood constituents, immunological, and antioxidant parameters of laying hens were embedded into a database. Statistical analysis was performed using a mixed model, with different studies treated as random effects and phytogenic extract levels treated as fixed effects. This meta-analysis revealed that dietary phytogenic extracts quadratically (p < 0.05) improved egg production and egg mass as well as decreased (p < 0.05) the feed conversion ratio (FCR) with no adverse effect on egg weight and egg quality. Feed intake and egg yolk percentage tended to increase linearly (p < 0.1). Total serum cholesterol and low-density lipoprotein (LDL) declined quadratically (p < 0.001 and p < 0.05, respectively), high-density lipoprotein (HDL) increased linearly (p < 0.001), and malondialdehyde (MDA) decreased linearly (p < 0.01), with increasing levels of dietary phytogenic extract. In addition, immunoglobulin G (IgG), immunoglobulin A (IgA), glutathione peroxidase (GSH-Px), and total superoxide dismutase (TSOD) increased linearly (p < 0.05) in line with the increase in dietary phytogenic extract level. It was concluded that the inclusion of phytogenic extracts in the diet of laying hens had a positive effect on productive performance, feed efficiency, egg mass, immunity, and antioxidant activity without interfering with egg quality. The optimum level of feed photogenic extract for egg production and feed efficiency was determined to be around 300 mg/kg feed.

The association of Curcuma and Scutellaria plant extracts improves laying hen thermal tolerance and egg oxidative stability and quality under heat stress conditions

Chronic exposure to high ambient temperatures is detrimental to laying hen performance and egg quality. Plant secondary metabolites may alleviate effects, partly due to their antioxidant activities. Herein, we investigated the effects of dietary supplementation with a phytonutrient solution (PHYTO) consisting of a plant extract combination of Scutellaria baicalensis and Curcuma longa on young layers (25–32 wk of age) raised under naturally elevated temperature conditions. Four hundred, 24-wk-old Lohmann hens were allocated in 50 cages and, after a week of adaptation, were offered a diet either containing 2 g/kg of PHYTO or not, for 8 wk. Hen BW was measured at the beginning and end of the trial, and egg production and feed intake were recorded weekly. At week 32, four eggs per cage were collected to determine egg quality characteristics as well as the rate of lipid and albumen oxidation in fresh eggs. At the end of the trial, two hens per cage were blood sampled for assessment of biochemical markers, one of which was euthanized for histopathological evaluation of the liver and intestine and assessment of intestinal histomorphometry. The herbal mixture supplementation significantly increased egg production rate at weeks 28 and 29 and for the overall production period, and feed efficiency at weeks 26–29. In addition, the degree of liver necrosis and microvascular thrombosis was lower (P < 0.05) whereas intestinal villosity was greater in duodenal and jejunal segments (P < 0.05) in the PHYTO compared to the control group. Supplementation also reduced (P < 0.05) blood concentrations of corticosterone, alanine aminotransferase activity, and TBARS, and a reduction in catalase activity was observed. Egg quality characteristics were not affected, except for eggshell thickness, egg diameter, and eggshell breaking strength that were superior in the PHYTO group (P < 0.05). PHYTO supplementation significantly improved egg lipid oxidation status of fresh eggs. In conclusion, supplementation with PHYTO improved laying hen productivity and egg quality, which was associated with an improvement in laying hen thermotolerance.

Impacts of polyphenols on laying hens' productivity and egg quality: A review

There has been a rapid increase in the world's output of main poultry products (meat and eggs). This reflects customer desire for these high-quality and safe products and the comparatively low price. Recently, natural feed additives, plants and products have been increasingly popular in the poultry and livestock industries to maintain and improve their health and production. Polyphenols are a type of micronutrient that is plentiful in our diet. They are phytochemicals that have health benefits, notably cardiovascular, cognitive function, antioxidant, anti-mutagenic, anti-inflammatory, antistress, anti-tumour, anti-pathogen, detoxification, growth-promoting and immunomodulating activities. On the other hand, excessive polyphenol levels have an unclear and sometimes negative impact on gastrointestinal tract health, nutrient digestion, digestive enzyme activity, vitamin, mineral absorption, laying hens performance and egg quality. As a result, this review illuminated polyphenols' various sources, classifications, biological activities, potential usage restrictions and effects on poultry, layer productivity and egg external and internal quality.

The Natural Product Curcumin as an Antibacterial Agent: Current Achievements and Problems

The rapid spread of antibiotic resistance and lack of effective drugs for treating infections caused by multi-drug resistant bacteria in animal and human medicine have forced us to find new antibacterial strategies. Natural products have served as powerful therapeutics against bacterial infection and are still an important source for the discovery of novel antibacterial drugs. Curcumin, an important constituent of turmeric, is considered safe for oral consumption to treat bacterial infections. Many studies showed that curcumin exhibited antibacterial activities against Gram-negative and Gram-positive bacteria. The antibacterial action of curcumin involves the disruption of the bacterial membrane, inhibition of the production of bacterial virulence factors and biofilm formation, and the induction of oxidative stress. These characteristics also contribute to explain how curcumin acts a broad-spectrum antibacterial adjuvant, which was evidenced by the markedly additive or synergistical effects with various types of conventional antibiotics or non-antibiotic compounds. In this review, we summarize the antibacterial properties, underlying molecular mechanism of curcumin, and discuss its combination use, nano-formulations, safety, and current challenges towards development as an antibacterial agent. We hope that this review provides valuable insight, stimulates broader discussions, and spurs further developments around this promising natural product.

Egg enrichment with n-3 fatty acids in farmed hens in sub-optimum temperature: A cold-temperament additive mix alleviates adverse effects of stress on performance and health

At some stage, laying hen farming is likely to be subjected to sub-optimum temperatures (SOTem) due to climate change. While egg enrichment with n-3 fatty acids is a common practice in the poultry industry, in SOTem it has been less investigated. This study tested the effects of egg enrichment through extruded flaxseed (FLX) (180 g/kg) alone or along with hulled-soaked barley (H-SB) (170 g/kg), namely FLBA, with and without a cold-temperament additive mix (CTA) (25 g/kg: 5 g/kg flixweed (Descurainia sophia), 10 g/kg dried herb-extraction residues from pussy willow (Salix aegyptiaca) and 10 g/kg dried lemon (Citrus limon) residue) in two temperatures (20°C and SOTem: 27°C) on egg performance, yolk fatty acids, lipid components, blood biochemistry, serological enzymes, antioxidant and immune system of Hy-Line W-36 53-week-old for 9 weeks. Two hundred seventy layers were randomly distributed to nine treatments, resulting in six replicates with five hens. Hens fed flaxseed diets, regardless of temperature or CTA, had higher levels of n-3 fatty acids in yolks than others. Temperature negatively influenced feed intake and egg production. FLX + H27 and FLBA + H27 groups outperformed the other groups regarding cholesterol in yolk (10.1, 10.3 mg/g yolk), high-density lipoprotein (HDL) (5.19, 4.93 mg/g yolk), total protein (FLX + H27: 6.82 mg/dl), HDL in the blood (FLBA + H27:83.8 mg/dl), superoxide dismutase (FLBA + H27:90.4 U/ml), glutathione reductase (FLBA + H27: 1042.1 U/ml), glutathione peroxidase (FLX + H27: 1149.7 U/ml) and catalase (FLBA + H27: 12.5 U/ml). Total antibody, immunoglobulin G and immunoglobulin M after 42 days were significantly higher in chicks fed CTA-added diets (p < 0.05). Replacing corn and soya bean meal with H-SB did not negatively change the above-mentioned factors. Our findings collectively suggest that egg enrichment with n-3 fatty acids through dietary FLBA + H27 (180 g/kg flaxseed, 170 g/kg H-SB, and 25 g/kg CTA) in SOtem is suggested without any adverse impacts.

Impact of Treating Hatching Eggs with Curcumin after Exposure to Thermal Stress on Embryonic Development, Hatchability, Physiological Body Reactions, and Hormonal Profiles of Dokki-4 Chickens

Simple Summary

Curcumin has been used as a suitable feed supplement for poultry to improve several hematological and biochemical indicators, diminish heat stress, and increase antioxidant activity. This experiment evaluated the effects of incubation temperatures and spraying hatching eggs with curcumin during the incubation phase on chick embryo development, hatchability, physiological body reactions, and hormonal profiles of Dokki 4 chickens. The findings indicated that the relative water loss and dead after piping in the chronic incubation temperature group were significantly increased compared with the normal incubation temperature group. Post-hatch, the triiodothyronine level in the high incubation temperature group was significantly decreased than in the control group. Regarding curcumin treatments, relative water loss from eggs and the hatchability of fertile eggs in treated groups significantly increased, while body surface temperature significantly decreased compared with the control.

Abstract

This study evaluated the impact of incubation temperature and spraying hatching eggs with curcumin during the early embryogenesis phase on chick embryo developments, hatchability, physiological body reactions, and hormonal profiles of Dokki 4 chickens. A total of 720 fertile eggs were equally distributed into two groups. In the first group, the eggs were incubated at normal incubation temperature/NIT (37.8 °C and 55–60% RH) for up to 19 days of incubation, whereas those in the second group were incubated in the same conditions except from 6 to 8 day, in which they were daily exposed to chronic incubation temperature/CIT (39.0 °C) for 3 h. Each group was classified into four curcumin treatment doses; the 1st treatment (control) was sprayed with distilled water, while the 2nd, 3rd, and 4th treatments were sprayed with 250, 500, and 1000 mg curcumin/liter distilled water. The results indicated that the lowest hatchability of fertile eggs (%) was obtained in the CIT group (p = 0.02), whereas the highest body surface temperature/BST compared in the NIT group (p = 0.01). Regarding curcumin treatments, the percentages of heart, gizzard, spleen, and T3 hormone levels in the treated group were significantly increased, while the H/L ratio was significantly reduced (p = 0.001) compared with the control. At 8 weeks of age, the testes and ovary percentages in treated groups were significantly (p = 0.05) increased compared with the control. In conclusion, exposure of hatching eggs to high thermal stress (39 °C) during the incubation phase had deleterious effects on chick performance and T3 hormone level. Moreover, spraying hatching eggs had beneficial impacts on growth, reproductive organs, T3 hormone level, and reducing H/L ratio.

Curcumin Extraction, Isolation, Quantification and Its Application in Functional Foods: A Review With a Focus on Immune Enhancement Activities and COVID-19

An entirely unknown species of coronavirus (COVID-19) outbreak occurred in December 2019. COVID-19 has already affected more than 180 million people causing ~3.91 million deaths globally till the end of June 2021. During this emergency, the food nutraceuticals can be a potential therapeutic candidate. Curcumin is the natural and safe bioactive compound of the turmeric (Curcuma longa L.) plant and is known to possess potent anti-microbial and immuno-modulatory properties. This review paper covers the various extraction and quantification techniques of curcumin and its usage to produce functional food. The potential of curcumin in boosting the immune system has also been explored. The review will help develop insight and new knowledge about curcumin's role as an immune-booster and therapeutic agent against COVID-19. The manuscript will also encourage and assist the scientists and researchers who have an association with drug development, pharmacology, functional foods, and nutraceuticals to develop curcumin-based formulations.

Effect of chlorogenic acid on intestinal inflammation, antioxidant status, and microbial community of young hens challenged with acute heat stress

Heat stress in poultry is deleterious to productive performance. Chlorogenic acid (CGA) exerts antibacterial, anti-inflammatory, and antioxidant properties. This study was conducted to evaluate the effects of dietary supplemental CGA on the intestinal health and cecal microbiota composition of young hens challenged with acute heat stress. 100-day-old Hy-line brown pullets were randomly divided into four groups. The control group (C) and heat stress group (HS) received a basal diet. HS + CGA₃₀₀ group and HS + CGA₆₀₀ group received a basal diet supplemented with 300- and 600-mg/kg CGA, respectively, for 2 weeks before heat stress exposure. Pullets of HS, HS + CGA₃₀₀ , and HS + CGA₆₀₀ group were exposed to 38°C for 4 h while the control group was maintained at 25°C. In this study, dietary CGA supplementation had effect on mitigate the decreased T-AOC and T-SOD activities and the increasing of IL-1β and TNFα induced by acute heat stress. Dietary supplementation with 600 mg/kg CGA had better effect on increasing the relative abundance of beneficial bacterial genera, such as Rikenellaceae RC9_gut_group, Ruminococcaceae UCG-005, and Christensenellaceae R-7_group, and deceasing bacteria genera involved in inflammation, such as Sutterella species. Therefore, CGA can ameliorate acute heat stress damage through suppressing inflammation and improved antioxidant capacity and cecal microbiota composition.

The functions of Patchouli and Elsholtzia in the repair of hen follicular granular cells after heat stress

The objective of this experimental study was to examine the effects of the Chinese herbal medicines Patchouli and Elsholtzia on the follicular granulosa cells of hens undergoing heat stress conditions. In the current investigation, hen follicular granulosa cells were isolated from the prehierarchical follicles of layer hens and then cultured in-vitro. The cells were randomly divided into the 6 groups. Following the completion of this study's experiments using different heat stress and medicinal treatments, the cell activities of each group were measured using an MTT method. The levels of the heat shock protein 70 (HSP70) were detected using ELISA. The expressions of the steroidogenic acute regulatory protein (StAR) mRNA; cytochrome P450 family 11, subfamily A, member 1 (CYP11A1) mRNA; proliferating cell nuclear antigen (PCNA) mRNA; and the follicle stimulating hormone receptor (FSHR) were detected using the real-time quantitative polymerase chain reactions. The concentration levels of estrogen and progesterone in the cell supernatant of each group were measured using ELISA. The results showed that cell activity had significantly decreased following the heat stress treatments at 43℃, 44℃, and 45℃ (P < 0.01), respectively. Meanwhile, cell activities observed in Patchouli and Elsholtzia were found to be much better than those of heat stress group (P < 0.05). In addition, the expression levels of HSP70 in the follicular granulosa cells of Patchouli and Elsholtzia groups were lower than those of heat stress group. Patchouli and Elsholtzia can maintain expressions of the receptor at 43℃. This study determined that the estrogen and progesterone in the supernatant fluid of Patchouli and Elsholtzia were higher than those observed in heat stress. Therefore, the results obtained in this study indicated that the Patchouli and Elsholtzia treatments administered prior the heat stress experiments had successfully protected the follicular granulosa cells from heat damages while maintaining the normal secretory functions of the granulosa cells.

Moringa oleifera Leaves as Eco-Friendly Feed Additive in Diets of Hy-Line Brown Hens during the Late Laying Period

Simple Summary

It is of the utmost importance to explore the merit of a new phytogenic feed additive for sustainable egg production in laying chickens during the late laying period. Thus, the current study was designed to evaluate the effect of the addition of Moringa oleifera leaves to laying hen diets on laying performance, egg quality, excreta ammonia concentrations and blood biochemical parameters. The findings showed that the egg production, weight and mass and eggshell quality of laying hens fed with Moringa oleifera leaves during the late laying period were significantly improved in comparison with those of the hens in the control group. Moringa oleifera leaves supplementation decreased excreta ammonia concentration and serum cholesterol and triglycerides as well as serum liver enzymes, uric acid, and creatinine levels compared to those of the control group.

Abstract

This study investigated the dietary effects of Moringa oleifera leaves supplementation on egg quality, laying performance, excreta ammonia concentrations and serum biochemistry of laying chickens during the late laying period. A total of 240 64-week-old Hy-Line Brown hens were assigned to four treatment diets including Moringa oleifera leaves at 0, 3, 6 or 9 g/kg, respectively, for eight weeks. The treatments had twelve replicates with five hens each. The results revealed that incremental dietary Moringa oleifera leaves significantly increased (p < 0.01) egg weight, production, and mass through 64–68, 68–72 and 64–72 weeks of age. Simultaneously, feed conversion ratio was significantly improved (p < 0.01) with Moringa oleifera leaves supplementation compared with the control. Haugh units and the thickness of eggshells significantly improved as a response to diets supplemented with 3, 6 and 9 g/kg Moringa oleifera leaves at 72 weeks of age. Interestingly, excreta ammonia concentrations, serum cholesterol, aspartate transaminase and alanine aminotransferase significantly decreased by Moringa oleifera leaves supplementation compared with the control group. In conclusion, introducing Moringa oleifera leaves supplementation at 3, 6 and 9 g/kg increased egg production, eggshell quality, Haugh units, and decreased serum cholesterol, triglycerides, excreta ammonia concentrations besides serum liver enzymes, uric acid and creatinine. Overall, based on the observed results, Moringa oleifera leaves supplementation was very promising and these leaves could be used as an effective feed additive in laying hens’ diet during the late laying period.

Nutritional manipulation to combat heat stress in poultry - A comprehensive review

Global warming and climate change adversely affect livestock and poultry production sectors under tropical and subtropical conditions. Heat stress is amongst the most significant stressors influencing poultry productivity in hot climate regions, causing substantial economic losses in poultry industry. These economic losses are speculated to increase in the coming years with the rise of global temperature. Moreover, modern poultry strains are more susceptible to high ambient temperature. Heat stress has negative effects on physiological response, growth performance and laying performance, which appeared in the form of reducing feed consumption, body weight gain, egg production, feed efficiency, meat quality, egg quality and immune response. Numerous practical procedures were used to ameliorate the negative impacts of increased temperature; among them the dietary manipulation, which gains a great concern in different regions around the world. These nutritional manipulations are feed additives (natural antioxidants, minerals, electrolytes, phytobiotics, probiotics, fat, and protein), feed restriction, feed form, drinking cold water and others. However, in the large scale of poultry industry, only a few of these strategies are commonly used. The current review article deliberates the different practical applications of useful nutritional manipulations to mitigate the heat load in poultry. The documented information will be useful to poultry producers to improve the general health status and productivity of heat-stressed birds via enhancing stress tolerance, oxidative status and immune response, and thereby provide recommendations to minimize production losses due to heat stress in particular under the growing global warming crisis.

Deposition, depletion, and potential bioaccumulation of bisphenol F in eggs of laying hens after consumption of contaminated feed

Increasing concerns over bisphenol A (BPA) as an endocrine disrupting chemical (EDC) and its adverse effects on both humans and animals have led to the substitution by structural analogs, such as bisphenol F (BPF), in many application areas. Information regarding to the carry-over of this emerging chemical in farm animals is essential for legislation and risk assessment purposes. In this study, a large-scale number of animal experiments were designed to investigate the transfer of BPF from feed to eggs. One control and three experimental groups of laying hens (72 hens per group) were fed with basal diets and BPF-contaminated feed at concentration levels of 0.1, 0.5 and 2.5 mg kg^-1, respectively, for two weeks. The hens were then fed with BPF-free diets for a further four weeks. Eggs were collected daily, and separated into egg yolk and white for BPF analysis. The effects of different levels of BPF exposure on laying performance followed a non-monotonic dose-response curve, since low level BPF (0.1 mg kg^-1) exposure did increase the laying rate, mean egg weight and daily feed intake, while high level BPF (2.5 mg kg^-1) exposure showed a decreasing trend. BPF residues were detected in both egg yolks and whole eggs after two days of administration, and plateau phase was achieved within 9-18 days. There are clear linear dose-response relationships between the plateau BPF concentrations in feed and eggs. The residue of BPF was found mainly in egg yolks with conjugated form and depleted slowly (still detected 21 days after feeding the BPF-free diet of the high level group). Mean carry-over rate of 0.59% BPF from feed to eggs was obtained. Compared with the carry-over rates of PCBs and dioxins, BPF showed a relatively minor trend of bioaccumulation in eggs. To the best of our knowledge, this is the first report on the deposition, depletion, and bioaccumulation study of bisphenols in farm animals. The quantity of data can therefore be helpful in the frame of risk assessment, especially for a comprehensive estimation of consumer exposure to the residues of bisphenols.

Turmeric powder in the diet of Japanese quails improves the quality of stored eggs

SUMMARY This study evaluated the effect of turmeric powder (TP) on the productivity and egg quality of quails and on the quality of eggs stored at different temperatures for 7 or 14 d. Quails were distributed in three treatments that consisted of sorghum-based diets with 1.5% and 3% TP or zero TP inclusion, with five replicates for 84 d. Eggs were stored at ambient temperature or refrigerated for 7 or 14 d in a 3 × 2 × 2 factorial arrangement with three TP levels × two storage temperatures (ST) × two storage periods (SP). Inclusion of TP did not affect the performance of the quails or egg quality at 84 d. Interaction SP × ST influenced the height and diameter of yolk and albumen, and the Haugh unit value. Eggs of quails with a diet supplemented with 3% TP and stored for 14 d showed specific gravity similar to the eggs stored for 7 d, despite the TP supplementation. It was concluded that diets with 3% TP did not affect the performance and quality of fresh eggs but improved the quality of eggs stored for 14 d at ambient temperature.

Effect of dietary supplementation of a phytogenic blend containing Schisandra chinensis, Pinus densiflora, and Allium tuberosum on productivity, egg quality, and health parameters in laying hens

Objective

This study was conducted to investigate the supplementary effect of a phytogenic blend (SPA: a mixture containing fermented Schisandra chinensis pomace, fermented Pinus densiflora needle extract, and Allium tuberosum powder in the ratio of 2:2:1) on egg production, egg quality, blood constituents, and visceral organs in laying hens.

Methods

A total of 135 Hy-line brown laying hens (48-wk-old) were randomly allocated to three dietary treatments with 5 replicates of 9 hens. The control group (CON) was fed a basal diet (no exogenous SPA addition) and the experimental groups were fed the basal diet containing SPA at the level of 0.1% and 0.3% for 6 weeks.

Results

The feed intake was significantly improved in SPA supplemented groups as compared with the control (p<0.05). However, egg production, daily egg mass, and feed conversion ratio were not different among the dietary treatments (p>0.05). For egg quality traits, only Haugh unit (HU) was significantly improved in SPA (0.3%) (p<0.05) as compared with other groups. However, HU was not affected during 4-wk of storage at 18°C among the dietary treatments (p>0.05). Furthermore, SPA supplementation did not affect the blood biochemical constituents except for the phosphate content, which was significantly higher in SPA groups than the CON group (p<0.05). There were no significant differences in visceral organ characteristics and immune indicators (immunoglobulin A [IgA], IgG, and IgM) in SPA or CON groups.

Conclusion

This study suggested that the supplementation of SPA may have beneficial effects on feed intake and egg quality in laying hens.

Dietary L-citrulline supplementation modulates nitric oxide synthesis and anti-oxidant status of laying hens during summer season

Background

L-citrulline (L-Cit), a non-protein amino acid, has been implicated in several physiological functions including anti-inflammatory, anti-oxidative, and hypothermic roles, however, there is a paucity of information with regards to its potential in poultry production.

Methods

This study was designed to investigate the effects of dietary L-Cit supplementation on the production performance, nitric oxide production, and antioxidant status of laying hens during summer period. Hy-Line Brown laying hens (n = 288, 34 weeks old) were allotted to four treatment, 6 replicates of 12 chickens each. Dietary treatments of control (basal diets), 0.25%, 0.50% and 1.00% L-Cit supplementation were fed to chickens for eight (8) weeks. Production performance, free amino acid profiles, nitric oxide production, and antioxidant properties were measured. Blood samples were collected at the 4^th and 8^th weeks of the experiment.

Results

Air temperature monitoring indicated an average daily minimum and maximum temperatures of 25.02 °C and 31.01 °C respectively. Dietary supplementation with L-Cit did not influence (P > 0.05) the production performance, and rectal temperature of laying hens. Egg shape index was increased (P < 0.05) with increasing levels of L-Cit. Serum-free content of arginine, citrulline, ornithine, tryptophan, histidine, GABA, and cystathionine were elevated, but taurine declined with L-Cit diets. Plasma nitric oxide (NO_x) concentration was highest at 1% L-Cit. Likewise, nitric oxide synthase (NOS) activity for total NOS (tNOS) and inducible NOS (iNOS) were upregulated with increasing L-Cit levels, although, tNOS was not affected at the 4^th week. Anti-oxidant enzymes including catalase and superoxide dismutase (SOD) were increased with L-Cit supplementation, however, SOD activity was unchanged at 4^th week, while total anti-oxidant capacity increased at the 8^th week. L-Cit supplementation attenuated the extent of lipid peroxidation, and also inhibited glutathione peroxidase activity.

Conclusion

Dietary L-Cit supplementation modulated systemic arginine metabolism, nitric oxide synthesis, antioxidant defense system, and increased the egg shape index of laying hens during the summer season. 1% L-Cit supplementation proved most effective in potentiating these effects and may be adopted for feed formulation strategies.

Impact of Heat Stress on Poultry Health and Performances, and Potential Mitigation Strategies

Heat stress is one of the major environmental stressors in the poultry industry resulting in substantial economic loss. Heat stress causes several physiological changes, such as oxidative stress, acid-base imbalance, and suppressed immunocompetence, which leads to increased mortality and reduced feed efficiency, body weight, feed intake, and egg production, and also affects meat and egg quality. Several strategies, with a variable degree of effectiveness, have been implemented to attenuate heat stress in poultry. Nutritional strategies, such as restricting the feed, wet or dual feeding, adding fat in diets, supplementing vitamins, minerals, osmolytes, and phytochemicals, have been widely studied and found to reduce the deleterious effects of heat stress. Furthermore, the use of naked neck (Na) and frizzle (F) genes in certain breed lines have also gained massive attention in recent times. However, only a few of these strategies have been widely used in the poultry industry. Therefore, developing heat-tolerant breed lines along with proper management and nutritional approach needs to be considered for solving this problem. Thus, this review highlights the scientific evidence regarding the effects of heat stress on poultry health and performances, and potential mitigation strategies against heat stress in broiler chickens and laying hens.

Thermal stress alters the basal value of serum proteins in laying hens

ABSTRACT This study aimed to evaluate the effect of thermal stress on the physiological and metabolic parameters in laying hens and the microbiological quality of eggs. The experiment was performed with 50 Rhode Island Red hens in the initial laying phase, under standard diet, lodged in 20 m² stalls under controlled temperature, for 30 days. The laying hens were randomly divided into two groups: G1 - the control group, which contained 10 hens exposed to the temperature of 17 ºC; G2 - the treatment group, which contained 40 hens exposed to the temperature of 30 ºC. The physiological parameters evaluated were: cloacal temperature, body surface temperature, heart rate, respiratory rate, and weight. Biochemical tests included total protein, albumin, globulin, and glucose. The group subjected to thermal stress showed lower body weight, increased heart rate, a slight increase in the respiratory rate, and increase in body surface temperature when compared with the control group (P < 0.05), although no significant differences were observed regarding cloacal temperature. As for the metabolic parameters, the treated group showed an increase in total proteins and globulins compared with the control group (P < 0.05), while albumin remained at basal levels. Additionally, hypoglycemia was observed in the treated group. Samples from egg shells and yolk were subjected to the analyses for the detection of Salmonella spp. These microorganisms were not detected amongst the egg samples.