Dietary 25-hydroxy-cholecalciferol and additional vitamin E improve bone development and antioxidant capacity in high-density stocking broilers.

This study aimed to investigate the effects of diets supplemented with 25-hydroxycholecalciferol [25-(OH)D3] and additional vitamin E on growth performance, antioxidant capacity, bone development, and carcass characteristics at different stocking densities on commercial broiler farms. A total of 118,800 one-day-old Arbor Acres broilers were assigned to a 2 × 2 factorial treatment consisting of two dietary vitamin levels (5,500 IU vitamin D3 and 60 IU vitamin E: normal diet, using half 25-(OH)D3 as a source of vitamin D3 and an additional 60 IU of vitamin E: 25-(OH)D3+VE diet) and two stocking densities (high density of 20 chickens/m2: HD and 16 chickens/m2: LD). The experiment lasted for 42 d. The results showed that high-density stocking negatively affected the growth performance of broilers during the first four weeks, whereas the vitamin diet treatment significantly improved the feed conversion ratios (FCR) during the last 2 wk. Vitamin diets increased catalase at 14 and 42 d, and the glutathione peroxidase (GSH-px) levels at 42 d in high-density-stocked broilers. The interaction showed that serum vitamin E levels were significantly improved at 28 d of age in high-density-stocked broilers as a result of the vitamin diets. Stocking density and dietary treatments were found to significantly affect bone development, with the vitamin diet significantly increasing metatarsal length and femoral bone strength in broilers from high-density stocking density at 28 d of age. High stocking density increased the proportion of leg muscles and meat yield per square meter. In general, 25-(OH)D3 and additional vitamin E suppressed oxidative stress and ameliorated the negative effects of high-density stocking on bone development in a commercial chicken farm setting. Vitamin diets improved the FCR of broilers, while high-density stocking resulted in better economic outcomes.

High-density stocking is often associated with animal welfare risks in broilers, mainly in terms of oxidative stress and bone development. Nevertheless, farming at too low a density remains for the most part economically unviable. Modulation of antioxidant capacity and bone development by nutritional strategies in high-density-farmed broilers has proven an effective tool in developing countries. Therefore, the present study investigated the effects of applying diets with a higher biological potency of vitamin D3 25-hydroxycholecalciferol [25-(OH)D3] and a higher concentration of vitamin E on broiler production performance, antioxidant capacity and meat production performance at different densities of stocking under commercial farming conditions. The results indicated that the vitamin dietary treatments suppressed oxidative stress and ameliorated the negative effects of high-density farming on bone development.

Glycerol monolaurate improves intestinal morphology and antioxidant status by suppressing inflammatory responses and nuclear factor kappa-B signaling in lipopolysaccharide-exposed chicken embryos.

Medium-chain fatty acids and their derivatives are natural ingredients that support immunological functions in animals. The effects of glycerol monolaurate (GML) on intestinal innate immunity and associated molecular mechanisms were investigated using a chicken embryo model. Sixty-four Arbor Acres broiler embryos were randomly allocated into four groups. On embryonic day 17.5, the broiler embryos were administered with 9 mg of GML, which was followed by a 12-h incubation period and a 12-h challenge with 32 µg of lipopolysaccharide (LPS). On embryonic day 18.5, the jejunum and ileum were harvested. Results indicated that GML reversed the LPS-induced decline in villus height and upregulated the expression of mucin 2 (P < 0.05). GML decreased LPS-induced malondialdehyde production and boosted antioxidant enzyme activity (P < 0.05). GML alleviated LPS-stimulated intestinal secretion of interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α (TNF-α) (P < 0.05). GML also normalized LPS-induced changes in the gene expression of Toll-like receptor 4, nuclear factor kappa-B p65 (NF-κB p65), cyclooxygenase-2, NOD-like receptor protein 3, IL-18, zonula occludens 1, and occludin (P < 0.05). GML enhanced as well the expression of AMP-activated protein kinase α1 and claudin 1 (P < 0.05). In conclusion, GML improved intestinal morphology and antioxidant status by alleviating inflammatory responses and modulating NF-κB signaling in LPS-challenged broiler embryos.

Glycerol monolaurate attenuated immunological stress and intestinal mucosal injury by regulating the gut microbiota and activating AMPK/Nrf2 signaling pathway in lipopolysaccharide-challenged broilers.

This study was conducted to investigate the effects of glycerol monolaurate (GML) on lipopolysaccharide (LPS)-induced immunological stress and intestinal mucosal injury in broilers and its underlying mechanisms. A total of 144 one-d-old Arbor Acres broilers were allocated to a 2 × 2 factorial arrangement involving dietary treatment (0 or 1,200 mg/kg dietary GML) and LPS challenge (injected with saline or Escherichia coli LPS on d 16, 18, and 20). Samples were collected on d 21. The results revealed that dietary GML augmented serum immunoglobulin A (P = 0.009) and immunoglobulin G (P < 0.001) levels in challenged birds. Dietary GML normalized LPS-induced variations in serum interleukin-6, interferon-gamma, and LPS levels (P < 0.05), jejunal villus height (P = 0.030), and gene expression of interleukin-6, macrophage inflammatory protein-3 alpha, Toll-like receptor 4, nuclear factor kappa-B, caspase-1, tight junction proteins, adenosine monophosphate-activated protein kinase alpha 1 (AMPKα1), nuclear factor-erythroid 2-related factor 2 (Nrf2), and superoxide dismutase-1 (P < 0.05). GML supplementation ameliorated LPS-induced peroxidation by reducing malondialdehyde content and increasing antioxidant enzyme activity (P < 0.05). Dietary GML enhanced the abundances of Anaerostipes, Pseudoflavonifractor, and Gordonibacter and reduced the proportion of Phascolarctobacterium in challenged birds. Dietary GML was positively correlated with alterations in antioxidant enzyme activities and AMPKα1, Nrf2, and zonula occludens-1 expressions. The genera Anaerostipes, Lachnospira, Gordonibacter, Lachnospira, Marvinbryantia, Peptococcus, and Pseudoflavonifractor were linked to attenuated inflammation and improved antioxidant capacity of challenged birds. In conclusion, dietary GML alleviated LPS-induced immunological stress and intestinal injury of broilers by suppressing inflammation and oxidative stress. Dietary GML regulated cecal microbiota and activated the AMPK/Nrf2 pathway in LPS-challenged broilers.

Glycerol Monolaurate Ameliorated Intestinal Barrier and Immunity in Broilers by Regulating Intestinal Inflammation, Antioxidant Balance, and Intestinal Microbiota.

This study was conducted to investigate the impact of glycerol monolaurate (GML) on performance, immunity, intestinal barrier, and cecal microbiota in broiler chicks. A total of 360 one-day-old broilers (Arbor Acres) with an average weight of 45.7 g were randomly allocated to five dietary groups as follows: basal diet and basal diets complemented with 300, 600, 900, or 1200 mg/kg GML. Samples were collected at 7 and 14 days of age. Results revealed that feed intake increased (P < 0.05) after 900 and 1200 mg/kg GML were administered during the entire 14-day experiment period. Dietary GML decreased (P < 0.05) crypt depth and increased the villus height-to-crypt depth ratio of the jejunum. In the serum and jejunum, supplementation with more than 600 mg/kg GML reduced (P < 0.05) interleukin-1ß, tumor necrosis factor-α, and malondialdehyde levels and increased (P < 0.05) the levels of immunoglobulin G, jejunal mucin 2, total antioxidant capacity, and total superoxide dismutase. GML down-regulate (P < 0.05) jejunal interleukin-1ß and interferon-γ expression and increased (P < 0.05) the mRNA level of zonula occludens 1 and occludin. A reduced (P < 0.05) expression of toll-like receptor 4 and nuclear factor kappa-B was shown in GML-treated groups. In addition, GML modulated the composition of the cecal microbiota of the broilers, improved (P < 0.05) microbial diversity, and increased (P < 0.05) the abundance of butyrate-producing bacteria. Spearman's correlation analysis revealed that the genera Barnesiella, Coprobacter, Lachnospiraceae, Faecalibacterium, Bacteroides, Odoriacter, and Parabacteroides were related to inflammation and intestinal integrity. In conclusion, GML ameliorated intestinal morphology and barrier function in broiler chicks probably by regulating intestinal immune and antioxidant balance, as well as intestinal microbiota.

Effect of dexamethasone on gene expression of cannabinoid receptor type 1 and adenosine monophosphate-activated protein kinase in the hypothalamus of broilers (Gallus domesticus).

Hypothalamic neural circuits play a critical role in integrating peripheral signals and conveying information about energy and nutrient status. We detected cannabinoid receptor type 1 (CB1) distribution in the hypothalamus, liver, duodenum, jejunum, and ileum among 7- and 35-day-old broilers. The effects of dexamethasone (DEX) on CB1 gene expression were evaluated by in vitro and in vivo experiments on glucocorticoid receptor (GR) and adenosine monophosphate-activated protein kinase (AMPK) in the hypothalamus of broilers. In vitro, hypothalamic cells from 17-day-old broiler embryos were incubated with either 0.1% dimethyl sulfoxide or DEX (100 nmol/mL) for 1 h. In the in vivo study, 28-day-old broilers were injected with DEX for 24 h or 72 h. Results showed that CB1 was mainly expressed in the hypothalamus, and 72 h DEX treatment increased the expression. One-day treatment of broilers with DEX did not change the hypothalamic CB1 gene expression. Moreover, DEX treatment for 24 h and 72 h increased the mRNA level of hypothalamic AMPKα2 and GR. However, no differences were observed on the gene expression of CB1, GR, and AMPKα2 in hypothalamic cells with DEX-treated for 1 h. In conclusion, CB1 is mainly expressed in the hypothalamus of broilers; 72-h DEX exposure can regulate the CB1 system and AMPK signaling pathway of the broiler hypothalamus.