Supplementation of two sources and three levels of iodine in the diet of laying hens: effects on performance, egg quality, serum and egg yolk lipids, antioxidant status, and iodine accumulation in eggs

Nutritional Impacts of Dietary Selenium, Iodine and their Interaction on Egg Performance, and Antioxidant Profile in Laying Longyuan Duck Breeders

The present study aimed to optimize the combined effect of dietary selenium (SE) and iodine (ID) on the productive and reproductive performance and antioxidant capacity of Longyuan breeding ducks. A total of 288 Longyan duck breeders aged 20 wk were randomly assigned to four groups with six replicates (n = 72 ducks/group; 12 ducks/replicate). A 2 × 2 factorial arrangement experiment was performed and included 2 supplementation levels of each SE and ID for 200 days of the experimental period. The first group (SE0/ID0) received a basal diet without SE or ID supplementation and was considered to be the control group, whereas the other three groups, SE0/ID4, SE2/ID0 and SE2/ID4, received a basal diet supplemented with 0.4 mg ID/kg, 0.2 mg SE/kg or 0.2 mg SE supplemented with 0.4 mg ID/kg, respectively. The results indicated that the albumin height of the SE2/ID0 group was lower (P < 0.05) than that of the control group, that the egg shape index of the SE2/ID4 and SE0/ID4 groups were lower (P < 0.05) than that of the control group (SE0/ID0), and that the SE concentration significantly increased (P < 0.05) in the SE2/ID0 and SE2/ID4 groups. Hatchability and embryonic mortality improved (P < 0.05) in the SE2/ID0 group. Plasma GSH-Px activity was increased (P < 0.05) by reducing the concentration of malondialdehyde (MDA) in the SE groups. In addition, the tibia length significantly increased (P < 0.05) in the ID (SE0/ID4 and SE2/ID4) groups compared with that in the control group, the plasma content of IGF-1 in the SE2/ID4 and SE0/ID4 groups were greater (P < 0.05) than that in the control group, and the bone mineral content increased (P > 0.05) in the SE2/ID0 and SE0/ID0 groups. Compared with those in the other groups, the mRNA expression of antioxidant-related genes, including Nrf2 and SHMT1 in the SE2/ID4 group was upregulated (P > 0.05), especially in the SE2/ID4 group. Overall, dietary treatment with SE2/ID4 (0.2 mg SE in 0.4 mg ID/kg diet) could be a suitable feed supplement for improving the the egg quality, health status, endogenous antioxidant content, antioxidant-related gene expression and pre-hatching quality of Longyuan duck breeders.

Advanced chelate technology-based trace minerals reduce inflammation and oxidative stress in Eimeria-infected broilers by modulating NF-kB and Nrf2 pathways

This study investigated the effects of substituting inorganic trace minerals (ITM) with advanced chelate technology-based TM (ACTM) in broiler chicken feed on productive performance, metabolic profile, humoral immunity, antioxidant status, and modulation of NF-kB and Nrf2 signaling pathways in mixed Eimeria species exposure. The study involved 480 newly hatched male broiler chickens, which were divided into 5 treatment groups, each with 6 replicate cages and 16 chickens per replicate. The experimental treatments included an uninfected negative control group fed a basal diet with recommended inorganic TM levels (NC), an infected positive control group fed the same diet (PC), a PC group supplemented with salinomycin (SAL), and two PC groups in which the basal diet was replaced with 50% and 100% ACTM instead of inorganic TM (ACTM50 and ACTM100, respectively). All groups, except for the NC group, were orally challenged with mixed Eimeria species oocysts on day 14. According to the results, the PC group showed lower feed intake, breast yield, low-density lipoprotein-cholesterol concentration, lactobacillus spp. counts, and serum IgG levels, but higher jejunal TGF-β expression versus the NC group. The broilers in the NC, SAL, and ACTM100 groups showed higher body weight gain, carcass yield, and TGF-β expression, but lower serum alkaline phosphatase activity, ileal E. coli count, and jejunal expression levels of IL-1β, IL-6, IFN-γ, Nrf2, and SOD1 compared to the PC group, with the NC group having the highest body weight gain and lowest IL-1β and Nrf2 expression levels. Furthermore, the administration of ACTM100 treatment improved feed efficiency, increased serum iron, zinc, manganese, and copper levels, enhanced total antioxidant capacity and different antioxidant enzyme activities, and reduced malondialdehyde concentration. In conclusion, complete replacement of ITM with ACTM effectively protects broilers from Eimeria infection, with similar positive effects to SAL treatment in terms of productive performance and anti-inflammatory responses and better antioxidant responses and mineral availability.

Optimal fermentation of Shuanghuanglian and its effects on production performance of laying hens

Background

Shuanghuanglian is a Chinese medicine composed of Honeysuckle Flower, Baical Skullcap Root, and Fructus Forsythiae. It has various effects, including anti-inflammatory, antibacterial, antiviral, and immunomodulatory effects. The fermented product of Shuanghuanglian can be used as an antibiotic alternative, as it has similar efficacy, which may improve the immunity, feed intake and utilization efficiency of laying hens, thus improving their production performance. The aim of this study was to optimize the fermentation conditions for Shuanghuanglian using single factor and response surface methodology, evaluate the chemical and microbial composition of the Shuanghuanglian fermentation liquor (SFL), and explore the effects of SFL on the production performance of laying hens.

Methods

A total of 288 Xinyang black-feather laying hens (50 week-old) were randomly allocated to four treatments with nine replicates, each replicate containing eight hens, for a total of 37 days trial (including a 7-day adaptation period). The treatments included a control group (0% SFL in drinking water) and drinking water supplemented with 0.3, 0.5, or 0.7% SFL.

Results

The fermentation optimization conditions for Shuanghuanglian were selected as a solid-to-liquid ratio at 1:7, 3% inoculation quantity, fermentation temperature at 28°C for 5 days, initial pH of 7, 60 mesh (sieved), and rotation speed of 150 r/min. Various bioactive compounds, such as myrtenol, 2-hexyn-1-ol, arsenous acid tris(trimethylsilyl) ester, 3(10)-caren-4-ol, and oxime-, methoxy-phenyl, were detected in SFL. The most abundant bacterial phyla in SFL were Proteobacteria and Firmicutes, with Acinetobacter being the most abundant genus. The most abundant fungal phyla were Phragmoplastophyta and Magnoliophyta. The 0.5 and 0.7% SFL supplementation in water increased egg weight and laying rate, while decreasing the feed-to-egg ratio of laying hens compared with the control group (p < 0.05). Additionally, 0.3, 0.5, and 0.7% SFL supplementation in water increased (p < 0.05) the Haugh unit, but there were no significant differences (p > 0.05) in albumen height, egg shape index, egg thickness, and yolk color of the eggs.

Conclusion

Supplementation of SFL under optimized conditions had a positive impact on the production performance of laying hens, especially when the supplementation amount reached 0.5%. This study provides a theoretical basis for the application of Shuanghuanglian in the commercial egg industry.

Potential benefits of advanced chelate-based trace minerals in improving bone mineralization, antioxidant status, immunity, and gene expression modulation in heat-stressed broilers

Organic sources of trace minerals (TM) in broiler diets are more bioavailable and stable than inorganic sources, making them particularly beneficial during challenging periods such as heat stress (HS) conditions. A 42-d study investigated the effects of using advanced chelate technology-based TM (ACTM) or adding varying amounts of ACTM to broiler diets during HS conditions. The study involved 672 male broiler chickens in 7 treatment groups, including a thermoneutral control (TNC) group and six HS treatments. There were 8 replicate pens per treatment and 12 birds per replicate. The six HS treatments included birds exposed to a cyclic HS environment (34°C) for 8 h and were as follows: HSC, which consisted of the same basal diet with the recommended ITM levels; ACTM50 and ACTM100, which replaced the basal diet with 50% and 100% ACTM instead of ITM; ITM+ACTM12.5 and ITM+ACTM25, which involved adding extra ACTM to the ITM basal diet at 12.5% and 25%, respectively; and ITM125, which used 125% of the recommended levels of ITM in the basal diet. Compared with the HSC treatment, the TNC, ACTM100, and ITM+ACTM25 treatments resulted in increased (P < 0.05) body weight; tibia weight; tibia ash, phosphorus, iron, and manganese contents; secondary antibody titers; and serum TAC and SOD values but decreased (P < 0.05) serum MDA concentrations and the expression levels of the hepatic genes IL-1β, IL-6, and INF-γ. The TNC and ACTM100 groups also showed greater (P < 0.05) feed efficiency, tibia length, tibia zinc content, and hepatic SOD1 expression but exhibited reduced (P < 0.05) hepatic NF-kB expression. Significant increases (P < 0.05) in primary anti-NDV titers, serum GPx1 activity, and Nrf2 and GPx1 gene expression levels were also detected in the ACTM100, ITM+ACTM12.5, and ITM+ACTM25 groups. In conclusion, the findings suggest that replacing ITM with ACTM or adding ACTM to ITM diets, especially at a 25% higher dose, can effectively protect broilers from heat stress by promoting growth, reducing inflammation, and increasing the expression of antioxidant proteins.

Organic Iodine Improves the Growth Performance and Gut Health of Fujian Yellow Rabbits

Organic iodine is a new trace element additive that is highly efficient in regulating cell growth, function, and metabolism. This study demonstrated that organic iodine improves the growth performance and gut health of Fujian yellow rabbits. A total of 160 healthy rabbits of similar weight were randomly divided into four groups, which were treated with organic iodine (0, 0.5, 1.0, and 1.5 mg/kg) for 60 days. Our results indicated that organic iodine improved the growth performance, including significantly increased BW, ADG, and ADFI, and decreased F/G notably. Organic iodine improved the content of T3, T4, IgM, IgA, and IgM in serum, and intestinal mucosal immunity (IL-1α, IL-2, and sIgA). Organic iodine supplementation ameliorated gut morphometry and morphology, such as higher villus height and lower crypt depth. Organic iodine increased the amount of goblet cells significantly. The 0.5 mg/kg organic iodine most increased the activities of amylase, cellulase, and trypsin in caecum. Organic iodine induced more active caecum fermentation, higher NH3-N, acetic acid, propionic acid, and butyric acid, while lowering PH. In conclusion, organic iodine improved the growth performance and gut morphometry and morphology, and increased caecum enzyme activities, active caecum fermentation, and intestinal immunity of Fujian yellow rabbits.

The Thyroid Hormone and Immunoglobulin Concentrations in Blood Serum and Thyroid Gland Morphology in Young Hens Fed with Different Diets, Sources, and Levels of Iodine Supply

The aim of this study was to examine the influence of the level (1, 3, and 5 mg I/kg) and source of iodine (KI, Ca(IO₃)₂, and KIO₃) on thyroid hormone and immunoglobulin concentrations in the blood serum of laying hens alongside a histological picture of the thyroid. In the first, birds were fed grain-soybean meal mixtures, and in the second, two kinds of diets based on corn-soybean or corn-soybean-rapeseed meal were applied. In the experiments, we determined the levels of the blood serum thyroid hormones fT₃ and fT₄, as well as the morphological structure of the thyroid gland. In the second experiment, the concentration of immunoglobulins in blood serum was assayed. In both experiments, no influence of iodine source on thyroid hormone concentration was observed. However, increasing the iodine level in the full mixture and adding rapeseed meal in both experiments caused an increase in fT₃ concentration. Increasing I-addition in both experiments led to a decrease in thyroid gland follicle diameter. Rapeseed meal inclusion (at a level of 10%) to the complete hen mixture led to an increase in thyroid gland follicle diameter. Applying KIO₃ as an iodine source in both experiments caused a decrease in the thyroid gland height of follicle epithelial cells. Immunoglobulin concentrations in the serum were not affected by experimental factors. The results suggest that the methodologies of studies on the bioavailability of minerals and the corresponding analytical methods require unification. The lack of such standardization makes it impossible to engage in a satisfactory discussion of the results and exchange experiences.

Positive effects of Mulberry leaf extract on egg quality, lipid metabolism, serum biochemistry, and antioxidant indices of laying hens

Plant extracts are becoming a hot topic of research by animal husbandry practitioners following the implementation of a global policy to restrict antibiotic use in animal production. Mulberry leaf extract has received considerable attention as a new plant extract. Mulberry leaf polysaccharides and flavonoids are its main constituents, and these substances possess immunoregulatory, hypoglycemic, antioxidant, and anticoagulant properties. It is however less common to use them in poultry production. Therefore, we investigated the effects of adding MLE to the diet of laying hens on egg quality, lipid metabolism, serum biochemistry, and antioxidant indices in this study. A total of 288 Lohmann Silber layers, aged 38 weeks, were randomly assigned to four groups (six replicates of 12 hens each). Hens were fed a basal diet supplemented with 0 (control diet), 0.4, 0.8, or 1.2% MLE for 56 d. Results showed that the addition of 0.4–1.2% MLE to the diet improved aspartate transaminase (AST) activity in the serum of laying hens, reduced low-density lipoprotein (LDL-C) content in the serum, and significantly decreased yolk triglyceride (TG) and total cholesterol (TC) contents (P < 0.05). No adverse effects were observed on production performance (P > 0.10). MLE (0.4 and 1.2%) significantly reduced the TG and TC levels in the liver (P < 0.05). MLE (0.8 and 1.2%) significantly increased glutathione peroxidase (GSH-Px) activity in the serum, decreased alanine transaminase (ALT) activity, TG and TC content in the serum, and improved egg yolk color (P < 0.05). MLE (1.2%) significantly increased high-density lipoprotein (HDL-C) content and superoxide dismutase (SOD) activity in the serum and enhanced eggshell strength (P < 0.05). The liver-related lipid metabolism gene assay revealed that the relative mRNA expression of PPARα and SIRT1 in the liver was significantly upregulated and that of FASN and PPARγ was significantly decreased after the addition of MLE. In contrast, the relative mRNA expression of SREBP-1c in the liver dramatically decreased after the addition of 0.8 and 1.2% MLE (P < 0.05). The addition of MLE to the diet improved egg quality and the economic value of hens by increasing antioxidant capacity and lipid metabolism. The most appropriate amount of MLE to be added to the diet of laying hens was 0.8%. Our study provides a theoretical reference for the application of MLE in egg production and to promote the healthy and sustainable development of the livestock and poultry industry under the background of antibiotic prohibition.