Effects of L-Methionine and DL-Methionine on Growth Performance, Methionine-Metabolizing Enzyme Activities, Feather Traits, and Intestinal Morphology of Medium-Growing, Yellow-Feathered Chickens between 1 and 30 Days of Age.

This experiment investigated the effects of L-Methionine (L-Met) on growth performance, Met-metabolizing enzyme activity, feather traits, and small intestinal morphological characteristics, and compared these with DL-Methionine (DL-Met) for medium-growing, yellow-feathered broilers during the starter phase. Furthermore, the aim was to provide recommendations for the appropriate dietary Met levels in feed. A total of 1584 1-d broilers were randomly divided into 11 treatment groups with six replicates of 24 birds each: basal diet (CON, Met 0.28%), basal diet + L-Met (0.04%, 0.08%, 0.12%, 0.16%, 0.20%), and basal diet + DL-Met (0.04%, 0.08%, 0.12%, 0.16%, 0.20%). The total trial period was 30 days. Compared with broilers fed the basal diet, those fed 0.04 to 0.20% supplemental Met had higher final body weight (FBW), average daily feed intake (ADFI), average daily gain (ADG), and lower feed-to-gain ratio (F: G) (p < 0.05). Compared with DL-Met groups, the L-Met group had higher FBW and ADG (p < 0.05). The relative bioavailability (RBV) of L-Met in ADG of 1-30 d was 142.5%. Chicks fed diets supplemented with L-Met had longer fourth primary feather lengths compared to birds fed the control and diets supplemented with DL-Met (p < 0.05). Compared to the control, birds supplemented with DL-Met or L-Met had an increased moulting score (p ≤ 0.05). Chicks fed diets supplemented with L-Met had lower activities of methionine adenosyl transferase (MAT) compared to those fed the basal diet or supplemented with DL-Met (p < 0.05). Chicks supplemented with either DL-Met or L-Met had higher activities of cystathionine ß-synthase (CBS) than those fed the basal diet (p < 0.05). Compared with the control, chicks fed diets supplemented with either DL-Met or L-Met had an enhanced level of albumin in plasma (p < 0.05). There were no obvious differences in the plasma content of uric acid and total protein among the treatments (p > 0.05). Chicks fed diets supplemented with either DL-Met or L-Met had higher villus height and V/C in the duodenal than chicks fed the basal diet (p < 0.05). The jejunum morphology was not affected by either L-Met or DL-Met supplementation (p > 0.05). Therefore, dietary supplementation with DL-Met or L-Met improved the growth performance, feather traits, and intestinal morphological characteristics of medium-growing, yellow-feathered broiler chickens aged 1 to 30 d by decreasing the enzyme activities of Met methylation (MAT) and increasing the enzyme activities of the sulfur transfer pathway (CBS), and supplementation with L-Met showed a better improvement compared with DL-Met. The relative efficacy of L-Met to DL-Met was 142.5% for ADG of yellow-feathered broilers. The appropriate Met levels for medium-growing, yellow-feathered broilers are between 0.36~0.38% (supplementation with DL-Met) or 0.32~0.33% (supplementation with L-Met) when based on ADG and feed-to-gain ratio.

Betaine as an alternative feed additive to choline and its effect on performance, blood parameters, and egg quality in laying hens rations.

This research aimed to evaluate how using betaine levels as a choline substitute affects productive performance, egg quality parameters, fatty acids profile, and antioxidant status in laying hens. One hundred and forty brown chickens, 45 wk old, were divided into 4 groups, each group of 7 replicates with 5 chickens per replicate. The first group of diets with choline has control (A) 100% choline, the second group (B) 75% choline + 25% betaine, the third group (C) 50% choline + 50% betaine, and the fourth group (D) received 100% betaine. No significant effects were observed in final body weight (BW), body weight gain (BWG), egg production (EW), and feed intake (FI) for laying hens. In the diet in which betaine was replaced choline, egg mass (EM) and egg weight (EW) increased compared to the control group (P < 0.05). Also, after 12 wk of feeding, the egg quality parameters were not influenced; however, yolk color was increased significantly compared with the control group. Serum total cholesterol, LDL-lipoprotein, HDL-lipoprotein, triglyceride, glucose, aspartate transaminase (AST), and alanine transaminase (ALT) were not affected by replacing choline with betaine. Furthermore, liver malondialdehyde (MDA) content, yolk vitamin E, and fatty acid levels were not significantly affected by replacing choline with betaine. Moreover, hens fed betaine displayed an increased antibody titer of the Newcastle disease (ND) virus. EW and EM were increased by 3.50% and 5.43% in 100% betaine group (D) when compared to the control group. Isthmus weight was decreased by 48.28 % in 50% choline + 50% betaine group (C) when compared to the control group. ND was increased by 26.24% in 100% betaine group when compared to the control group. In conclusion, betaine supplementation positively affected productive performance, egg quality measurements, and immunity response in Bovans brown laying hens.

Potential of Spirulina platensis as a feed supplement for poultry to enhance growth performance and immune modulation.

Increase in drug resistance as well as ineffective immunization efforts against various pathogens (viruses, bacteria and fungi) pose a significant threat to the poultry industry. Spirulina is one of the most widely used natural ingredients which is becoming popular as a nutritional supplement in humans, animals, poultry and aquaculture. It contains protein, vitamins, minerals, fatty acids, pigments, and essential amino acids. Moreover, it also has considerable quantities of unique natural antioxidants including polyphenols, carotenoids, and phycocyanin. Dietary supplementation of Spirulina can beneficially affect gut microbial population, serum biochemical parameters, and growth performance of chicken. Additionally, it contains polyphenolic contents having antibacterial effects. Spirulina extracts might inhibit bacterial motility, invasion, biofilm formation, and quorum sensing in addition to acting directly on the bacterium by weakening and making the bacterial cell walls more porous, subsequently resulting in cytoplasmic content leakage. Additionally, Spirulina has shown antiviral activities against certain common human or animal viruses and this capability can be considered to exhibit potential benefits against avian viruses also. Spirulan, a calcium-rich internal polysaccharide of Spirulina, is potentially responsible for its antiviral effect through inhibiting the entry of several viruses into the host cells, boosting the production of nitric oxide in macrophages, and stimulating the generation of cytokines. Comparatively a greater emphasis has been given to the immune modulatory effects of Spirulina as a feed additive in chicken which might boost disease resistance and improve survival and growth rates, particularly under stress conditions. This manuscript reviews biological activities and immune-stimulating properties of Spirulina and its potential use as a dietary supplement in poultry to enhance growth, gut health and disease resistance.

Dietary protocatechuic acid ameliorates ileal mucosal barrier injury and inflammatory response and improves intestinal microbiota composition in Yellow chickens challenged with Salmonella typhimurium.

Salmonella typhimurium (ST) is a common foodborne pathogen that severely affects the health of humans and livestock. Protocatechuic acid (PCA) has been shown to possess anti-inflammatory and anti-bacterial functions. Chickens were used to investigate the effect of PCA on the gut health infected with ST. A total of one hundred eighty, 1-d-old birds were randomly allocated into 3 treatments, each with 6 replicates per treatment and 10 chicks per replicate. Broiler chicks in the control and ST treatment were fed a basal diet, and birds in the PCA+ST treatment received the basal diet with 600 mg/kg PCA. On d 14 and 16 of the trial, broilers in ST and PCA+ST treatments received an oral dose of ST, while broilers in CON received an equal amount of PBS. The data were analyzed by the one-way ANOVA. Dietary PCA increased (P < 0.05) final body weight, average daily gain, and feed to gain ratio in ST-challenged Yellow broilers. Protocatechuic acid significantly alleviated ST-induced intestinal mucosal injury reflected in the decreased (P < 0.05) plasma activity of diamine oxidase and ileal apoptosis, with increased (P < 0.05) ileal villus height and villus height/crypt depth. Protocatechuic acid treatment significantly decreased (P < 0.05) ST-induced proinflammatory cytokine (Interleukin-1ß, Interleukin-6, Tumor necrosis factor-α, and Interferon-ß) content in ileum. Meanwhile, PCA treatment significantly increased (P < 0.05) the transcript abundances of claudin 1 (CLDN1), zonula occludens-1 (ZO-1), and mucin 2 (MUC2) in ileum, all related to the intestinal barrier in ST-challenged Yellow broilers. Additionally, PCA also increased (P < 0.05) the diversity and richness of the cecal microflora as reflected by reduced (P < 0.05) abundance of Bacteroidota, Proteobacteria and Escherichia-Shigella, and increased (P < 0.05) abundance of Firmicutes and Lactobacillus in ST-challenged Yellow broilers. These findings indicate that PCA relieves ST-induced loss weight, intestinal barrier injury, inflammatory response, and improves intestinal microbiota composition in Yellow broilers.

Dietary supplementation with anthocyanin attenuates lipopolysaccharide-induced intestinal damage through antioxidant effects in yellow-feathered broiler chicks.

This study investigated the protective effects of anthocyanin (AC) supplementation on lipopolysaccharide (LPS)-challenged yellow-feathered broiler chicks. A total of 480 1-d female broiler chicks were randomly assigned to 4 treatment groups: basal diet (CON), basal diet + LPS-challenge (LPS), supplementation with 100 or 400 mg/kg AC + LPS-challenge (AC100, AC400). On d 17 and d 19, birds in LPS, AC100 and AC400 received an intramuscular dose of LPS, while birds in CON received saline. The result showed that (1) LPS injection significantly decreased (P < 0.05) body weight on d 21 and average daily gain of broiler chicks from 1 to 21 days of age, and supplementation with 100 mg/kg AC increased (P < 0.05) those of LPS-challenged broilers. (2) There were no differences among the treatments (P > 0.05) in relative weights of immune organs. (3) Supplementation with AC (AC100 and AC400) increased (P < 0.05) the jejunal villus height and villus height/crypt depth ratio (AC100) of LPS-challenged birds. Challenge with LPS decreased the relative expression of OCLN (Occludin), ZO-1, JAM2, and MUC2 in jejunal mucosa of broilers, and supplementation with AC offset the relative expression of ZO-1, JAM2 (AC100 and AC400), and OCLN (AC400) in LPS-injected broilers. (4) LPS-induced increase in the malondialdehyde (MDA) concentration and decreases in activity of total superoxide dismutase (T-SOD), and expression of SOD1, CAT and GPX in jejunal mucosa, were attenuated by dietary AC supplementation. In conclusion, in yellow-feathered broiler chicks, dietary supplementation with AC alleviated LPS-induced declined growth performance and mucosal damage of the intestine through antioxidant effects.

Curcumin alleviates LPS-induced intestinal homeostatic imbalance through reshaping gut microbiota structure and regulating group 3 innate lymphoid cells in chickens.

Gastrointestinal dysfunction is associated with a disturbance of immune homeostasis, changes in the intestinal microbiome, alteration of the composition of the bile acid pool, and dynamic imbalance of group 3 innate lymphoid cells (ILC3s). Curcumin (CUR), a polyphenolic compound isolated from turmeric, has been known to attenuate intestinal inflammation in potential therapies for gastrointestinal diseases. It was hypothesized that CUR could target the gut microbiome to modulate bile acid (BA) metabolism and the function of ILC3s in ameliorating lipopolysaccharide (LPS)-induced imbalance of intestinal homeostasis in chickens. Seven hundred and twenty 1-day-old crossbred chickens were randomly divided into four treatments, namely CON_saline (basal diet + saline control), CUR_saline (basal diet + 300 mg kg-1 curcumin + saline), CON_LPS (basal diet + LPS), and CUR_LPS (basal diet + 300 mg kg-1 curcumin + LPS), each consisting of 6 replicates of 30 birds. On days 14, 17, and 21, the chickens in the CON_LPS and CUR_LPS treatments were intraperitoneally injected with LPS at 0.5 mg per kg BW. Dietary CUR supplementation significantly decreased LPS-induced suppression of growth performance and injury to the intestinal tight junctions and decreased the vulnerability to LPS-induced acute inflammatory response by inhibiting pro-inflammatory (interleukin-1ß and tumor necrosis factor-α) cytokines. CUR reshaped the cecal microbial community and BA metabolism, contributing to regulation of the intestinal mucosal immunity by promoting the anti-inflammatory (interleukin 10, IL-10) cytokines and enhancing the concentrations of primary and secondary BA metabolites (chenodexycholic acid, lithocholic acid). LPS decreased farnesoid X receptor (FXR) and G protein-coupled receptor class C group 5 member A synthesis, which was reversed by CUR administration, along with an increase in interleukin 22 (IL-22) production from ILC3s. Dietary supplementation of CUR increased the prevalence of Butyricicoccus and Enterococcus and enhanced the tricarboxylic acid cycle of intestinal epithelial cells. In addition, curcumin supplementation significantly increased sirtuin 1 and sirtuin 5 transcription and protein expression, which contributes to regulating mitochondrial metabolic and oxidative stress responses to alleviate LPS-induced enteritis. Our findings demonstrated that curcumin played a pivotal role in regulating the structure of the intestinal microbiome for health promotion and the treatment of intestinal dysbiosis. The beneficial effects of CUR may be attributed to the modulation of the BA-FXR pathway and inhibition of inflammation that induces IL-22 secretion by ILC3s in the intestinal lamina propria.

Dietary fiber modulates abdominal fat deposition associated with cecal microbiota and metabolites in yellow chickens.

Excessive deposition of abdominal fat is a public concern in the yellow chicken industry related to human nutrition. The common practice of nutritionists is to increase the fiber content in feed to control abdominal fat deposition of chickens. Corncob meal (CCM) is the cheapest ingredient widely used in animal diets. The possible effects of CCM on chicken abdominal fat deposition and the possible mechanism involving cecal microbiota remain unknown. The objectives of this study were to investigate the effects of CCM in modulating abdominal fat deposition and the role of the cecal microbiota and their metabolites. A total of 200 ninety-day-old Huxu female chickens were divided into 2 dietary treatments, each with 10 replicates of 10 birds, and were fed two finisher diets, from 90 to 135 d. The diets were a typical corn-soybean control diet (CON) and that diet with CCM partially replacing corn and corn gluten meal. Results showed that the CCM diet markedly decreased live weight and abdominal fat percentage (P < 0.05); chickens fed the CCM diet exhibited lower (P < 0.01) expression in abdominal fat of fatty acid binding protein 4 (FABP4), stearoyl-CoA desaturase (SCD), fatty acid synthase (FAS), and peroxisome proliferator-activated receptor γ (PPARγ) but higher (P < 0.05) expression of estrogen receptor alpha (ESR1). The CCM increased the abundance of Akkermansia (P < 0.05) and markedly reduced the relative cecal abundance of Phascolarctobacterium (P < 0.01), Rikenellaceae (P < 0.05), and Faecalibacterium (P < 0.01). The metabolomic and biochemical analyses demonstrated that the CCM diet increased (P < 0.05) the concentrations of butyrate in cecal contents. The majority of the metabolites in cecal digesta with differences in abundance were organic acids. The CCM diet increased (P < 0.05) contents of (R)-5-diphosphomevalote, pantothenic acid, 2-epi-5-epi-valiolone 7-phosphate, D-ribose 5-diphosphate, arbutin 6-phosphate, D-ribitol 5-phosphate, undecanoic acid, nicotinic acid, 4-methyl-2-oxovaleric acid, while decreasing (P < 0.05) those of oleic acid, glutaric acid, adipic acid, suberic acid, and L-fuculose 1-phosphate. In conclusion, these findings demonstrated that the dietary CCM treatment significantly decreased abdominal fat and altered the cecal microbiota and metabolite profiles of the yellow chickens.

The therapeutic effect of bromocriptine as mesylate and estradiol valerate on serum and blood biochemistry of common quails.

Hematology and serum biochemistry study may provide antique knowledge about the physical status of individuals, making them a valuable tool to differentiate healthy animals from affected animals. We aimed to investigate Steroid safety levels in birds through ex-situ studies at regular therapeutic doses. A total of 100 birds were used for hematology and serum biochemistry. This study was designed into 2 trials over the summer and winter, each comprised 5, 10, 15, and 20 d. Each study group was based on 5 control group birds and 20 experimental group birds. A sum of 2 groups representing 2 different steroids trial groups was treated with therapeutic doses to the stretch of 5, 10, 15, and 20 d each season. A therapeutic dose of each of the steroids was given at the rate of 3 drops 2 times a day to each bird. Analysis of data reveals that steroids had severe effects on bird's (Coturnix coturnix) hematological parameters. In most trials, the hematological effects of bromocriptine as mesylate showed an increase in red blood cell count and white blood cell count. On the other hand, steroid estradiol valerate showed a decrease in these parameters. Effect of steroids on serum biochemistry profile indicate acute damage to vital organs, especially to liver and kidney, indicating an increase in cholesterol, total protein, albumin, urea, and uric acid. The overall effect of steroids on the bird's serum and biochemistry of quails were nearly similar but different only in their intensity.

Effects of dietary oregano essential oil supplementation on growth performance, intestinal antioxidative capacity, immunity, and intestinal microbiota in yellow-feathered chickens.

Essential oils are plant-derived aromatic volatile oils, and they contain bioactive compounds that have been shown to improve poultry nutrition. In this study, we investigated the effects of oregano essential oil (OEO) on intestinal antioxidative capacity, immunity, and gut microbiota of young yellow-feathered chickens. A total of nine hundred and sixty 1-d-old female Qingyuan partridge chickens were randomly allocated to four treatment groups with six replicates of 40 birds each, and the feeding trial was lasted for 30 d. The controls were fed on a basal diet without in-feed antibiotics; the birds in the antibiotic group were fed the basal diet supplemented with 20 mg/kg virginiamycin; the remaining birds were fed the basal diet containing 150 or 300 mg/kg OEO, respectively. Dietary supplementation with 150 or 300 mg/kg OEO increased average daily feed intake (P = 0.057) and average daily gain (P < 0.05). The activities of glutathione peroxidase and total antioxidative capacity in plasma, jejuna, and ileal mucosa were increased by OEO supplementation (P < 0.05), with a trend of lower jejunal content of malonaldehyde (P = 0.062). Moreover, dietary OEO increased the content of secretory immunoglobulin A (P = 0.078) and the relative expression of Claudin 1, Mucin 2, and Avain beta-defensin 1 in ileum (P < 0.05). Sequencing data of 16S rRNA indicated that dietary OEO increased the relative abundance of Firmicutes phylum, and Clostridium and Lactobacillus genera, and decreasing that of Romboutsia. Functional analyses indicated that microbial amino sugar and nucleotide sugar metabolism, replication, and repair systems were higher in OEO groups than those of controls and antibiotic treatment. In conclusion, dietary supplementation with OEO enhanced growth performance, alleviated local oxidative stress in intestine, improved production of natural antibodies, and favorably modulated intestinal microbiota composition.

Effects of dietary iron on reproductive performance of Chinese Yellow broiler breeder hens during the egg-laying period.

The objective of this study was to investigate the effects of dietary iron (Fe) on reproductive performance of Chinese Yellow broiler breeder hens during the egg-laying period. A total of 480, 55-wk-old hens were balanced for laying rate and then randomly allotted into 5 groups, each with 6 replicates (8 cages for each replicate with 2 birds per cage). The trial was for 10 wk. Birds were fed diet with 44, 58, 72, 86, or 100 mg/kg Fe contained feed. Laying performance, biochemical indices and reproductive hormones in plasma, egg quality, ovarian and oviductal variables, tibial breaking strength, and hatching performance were determined. The key performance variables hematocrit, hatchability of live embryos, and tibial breaking strength were selected for analysis by quadratic polynomial (QP) and broken-line (BL) regressions to better determine optimal dietary Fe level. Qualified egg (excluding those with double-yolk, soft-shell, cracked, very small malformed, etc.) rate tended to decrease with the lowest and highest dietary Fe levels. Hematocrit was affected (P = 0.003) by dietary Fe, along with linear (P = 0.017) and quadratic (P = 0.002) effect. There was a significant effect (P = 0.034) of dietary Fe level on tibial breaking strength of breeder hens with a quadratic (P = 0.044) effect. Breeder hens fed inadequate (44 mg/kg diet) or excess (100 mg/kg) Fe both had lower (P < 0.05) tibial breaking strength compared to that of hens fed 86 mg/kg Fe. Hatchability of live embryos was affected (P = 0.004) by diet; with both linear (P = 0.014) and quadratic (P = 0.001) effects. Maximal hatching of live embryos occurred with diets of breeder hens containing 72 mg/kg Fe. From the QP and BL models fitted to hematocrit, tibial breaking strength, and hatchability variables, the optimal dietary Fe level for Chinese Yellow broiler breeder hens in the laying period was 70-90 mg/kg. The daily Fe fed (allowance) was about 8-11 mg.

Effects of maternal and dietary vitamin A on growth performance, meat quality, antioxidant status, and immune function of offspring broilers.

The aim of this study was to evaluate the effects of maternal and dietary vitamin A (VA) level on growth performance, meat quality, antioxidant status, and immune function of offspring broilers. Chinese yellow-feathered breeder hens were fed a basal diet supplemented with 0, 5,400, 10,800, and 21,600 IU/kg VA for 8 wk, with 6 replicates of 22 hens per replicate. Then the offspring hatched from each of the 4 maternal groups were fed a basal diet supplemented with 0 or 5,000 IU/kg VA for 63 D. Overall, there were 8 treatment combinations, each with 6 replicate pens of 20 birds. Results showed that (1) providing VA in offspring diets increased final body weight (FW), average daily gain, and average daily feed intake but reduced feed-to-gain ratio and mortality of offspring broilers (P < 0.05), whereas maternal provision of VA did not significantly affect the growth performance and mortality of offspring broilers. Maternal or offspring VA did not affect proportion of breast or thigh muscle (P > 0.05). (2) Maternal feeding with 21,600 IU/kg VA increased (P < 0.05) pH 24 h postmortem of breast muscle, compared with those without maternal supplication of VA. Dietary provision of 5,000 IU/kg VA in the posthatching diet decreased (P < 0.05) drip loss, yellowness (b∗) value and lightness (L∗) value, and increased shear force and pH of breast muscle compared with those without dietary VA supplication. (3) Maternal or offspring VA did not affect the activities of total superoxide dismutase and glutathione peroxidase (GSH-Px) or the content of malondialdehyde; however, there was a significant interaction (P < 0.05) between maternal and offspring VA on the activity of GSH-Px in serum. (4) Dietary provision of 5,000 IU/kg VA increased (P < 0.05) the weight proportion of liver and bursa of fabricius, whereas maternal feeding with 21,600 IU/kg VA increased the hatchling BW. Maternal feeding with 5,400 and 21,600 IU/kg VA decreased (P < 0.05) splenic interferon-γ (IFN-γ) transcripts and increased (P < 0.05) those of interleukin-2 (IL-2) in the progeny. There were interactions (P < 0.05) between maternal and offspring VA on splenic IL-2, IL-1ß, and IFN-γ expression. In summary, maternal and offspring provision of VA both had influence on meat quality and immune function in progeny broilers. Dietary VA increased growth performance, whereas the maternal VA affected the initial body weight of progeny when hatched, but the difference in performance caused by maternal VA level was able to be eliminated by dietary VA supplementation. Therefore, offspring provision had greater importance than maternal VA in the production; however, both should be considered in broiler nutrition to achieve good meat quality and immune status of broilers.

Effects of Dietary Iron Level on Growth Performance, Immune Organ Indices and Meat Quality in Chinese Yellow Broilers.

The objective of three trials was to investigate the effects of dietary Fe on growth performance, immune organ indices and meat quality of Chinese yellow broilers during the whole growth period. A total of 1440 1-day-old, 1440 22-day-old, and 1080 43-day-old Lingnan yellow male broilers were randomly assigned to one of six dietary treatments with six replicates per treatment (40 birds per replicate for both 1 to 21 d and 22 to 42 d, 30 birds for 43 to 63 d). Additional Fe (0, 20, 40, 60, 80, and 100 mg/kg) was added as FeSO4 • H2O to the three basal diets (calculated Fe 50 mg/kg, analyzed 48.3, 49.1, 48.7 mg/kg, respectively). The calculated final dietary Fe concentrations in Starter, Grower and Finisher phases were 50, 70, 90, 110, 130, and 150 mg/kg. The results showed that average daily gain (ADG), average daily feed intake (ADFI) and feed conversion rate (FCR) of the broilers were not influenced by the different levels of Fe (p> 0.05). Weight indices of the spleen, thymus and bursa of Fabricius were not influenced (p > 0.05) by the different levels of Fe during three 21-day experimental periods. Hematocrit, and Fe contents of the liver and kidney were not affected by different levels of Fe (p> 0.05). The diet with 150 mg/kg of Fe increased the a* (relative redness) value of breast muscle compared to the 50 and 70 mg/kg diets at 24 h post mortem (p< 0.05). The diet with 90 mg/kg Fe increased the pH of breast muscle compared to broilers fed 50 or 150 mg/kg Fe (p < 0.05) 45 min after slaughter. The diet with 90 mg/kg Fe decreased drip loss of breast muscle compared to 150 mg/kg Fe (p< 0.05). These data suggest that feeding yellow-feathered broilers on a conventional corn-soy based diet satisfies their requirements without additional Fe at ages 1 to 21, and 22 to 42 d, while 90 mg/kg in the finisher phase improved meat quality, and from the QP (quadratic polynomial) models of the key meat quality variables, pH of breast muscle and drip loss of breast muscle, the optimal dietary Fe level was 89 to 108 mg/kg, and daily Fe fed allowance was 11 to 13 mg in the finisher phase (43 to 63 d).

Effects of dietary perilla seed oil supplementation on lipid metabolism, meat quality, and fatty acid profiles in Yellow-feathered chickens.

This study evaluated the effect of the dietary replacement of 1% lard (CT) with 1% perilla oil (PO), 0.9% perilla oil + 0.1% anise oil (PA), or 0.9% perilla oil + 0.1% ginger oil (PG) on indices of lipid metabolism, antioxidant capacity, meat quality, and fatty acid profiles from Yellow-feathered chickens at day 63. Compared with the CT chickens, those given perilla oil had decreased (P < 0.05) plasma lipid levels including triglycerides (TG), total cholesterol (TCH), and low-density lipoprotein cholesterol (LDL-C). Hepatic TG, TCH levels, and fatty acid synthase activity were also decreased (P < 0.05) in chickens fed diets containing perilla oil. Abdominal fat percentage was significantly decreased in birds fed the PG compared to CT diets. Birds fed the PA or PG diets had increased (P < 0.05) hepatic total SOD, glutathione peroxidase, and glutathione-S-transferase than in chickens given PO alone. In addition, the content of reduced glutathione (GSH) in breast muscle was lower (P < 0.05) in birds fed PO compared with those given PG, and the reverse was true for content of malondialdehyde. Compared with the CT diet, the PO diet decreased breast muscle shear values and increased yellowness (b*) of breast muscle (P < 0.05). Birds fed the PA or PG diets had meat with better overall acceptability than those fed the CT diet. Chickens fed perilla oil diets exhibited higher contents of α-linolenic acid (C18:3n-3), DHA (22:6n-3), polyunsaturated fatty acids, and n-3 fatty acids, together with a lower content of myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), total saturated fatty acids, and n-6/n-3 ratio compared to controls (P < 0.05). These findings indicate that perilla oil has the potential to decrease lipid-related indices and improve fatty acid profiles of breast meat in chickens without adverse effect on antioxidant status or meat quality; this was even better when perilla oil was given together with anise oil or ginger oil.

Protocatechuic acid improved growth performance, meat quality, and intestinal health of Chinese yellow-feathered broilers.

The aim of this study was to investigate the effect of protocatechuic acid (PCA) on the growth performance, meat quality, and intestinal health of Chinese yellow-feathered broilers. Growing broilers were fed the basal diet or diets supplemented with 300 or 600 mg/kg PCA, or 200 mg/kg enramycin for 52 D. We found that addition of 300 mg/kg PCA significantly increased body weight, live weight, and carcass weight and decreased the feed to gain ratio of broilers; PCA improved meat quality through reducing shear force, and increasing a* (relative redness) and decreasing b* (relative yellowness) at 24 h after slaughter. The activities of alkaline phosphatase and diamine oxidase in plasma were significantly decreased by administration of 300 mg/kg PCA; PCA also significantly increased total antioxidant capability and decreased malondialdehyde content and activity of xanthine oxidase in liver. Meanwhile, it enhanced activities of total superoxide dismutase, glutathione s-transferase, and glutathione peroxidase in the jejunal mucosa. Interleukin-10 and transforming growth factor-ß were significantly increased in jejunal mucosa and plasma of 300 mg/kg PCA diet group, whereas interluekin-2 and interferon-γ dropped dramatically. Moreover, relative expression of apoptosis-related genes decreased in liver, whereas that of intestinal barrier-related and immunity-related genes increased in jejunum. Furthermore, 300 mg/kg PCA treatment significantly changed α-diversity and structure of the cecal microflora in broilers, with increasing relative abundance of Firmicutes and Actinobacteria while reducing Bacteroidetes and Proteobacteria. These results indicated that PCA improved the feed efficiency, growth performance, meat quality of broilers, and antioxidant capacity. It also enhanced intestinal immune function and improved the structure of intestinal flora to favor improved intestinal health in Chinese yellow-feathered broilers.

Harmful Effects and Control Strategies of Aflatoxin B1 Produced by Aspergillus flavus and Aspergillus parasiticus Strains on Poultry: Review.

The presence of aflatoxin B1 (AFB1) in poultry diets decreases the hatchability, hatchling weight, growth rate, meat and egg production, meat and egg quality, vaccination efficiency, as well as impairing the feed conversion ratio and increasing the susceptibility of birds to disease and mortality. AFB1 is transferred from poultry feed to eggs, meat, and other edible parts, representing a threat to the health of consumers because AFB1 is carcinogenic and implicated in human liver cancer. This review considers how AFB1 produced by Aspergillus flavus and Aspergillus parasiticus strains can affect the immune system, antioxidant defense system, digestive system, and reproductive system in poultry, as well as its effects on productivity and reproductive performance. Nutritional factors can offset the effects of AFB1 in poultry and, thus, it is necessary to identify and select suitable additives to address the problems caused by AFB1 in poultry.

Glycyrrhizic acid activates chicken macrophages and enhances their Salmonella-killing capacity in vitro.

OBJECTIVE: Salmonella enterica remains a major cause of food-borne disease in humans, and Salmonella Typhimurium (ST) contamination of poultry products is a worldwide problem. Since macrophages play an essential role in controlling Salmonella infection, the aim of this study was to evaluate the effect of glycyrrhizic acid (GA) on immune function of chicken HD11 macrophages. METHODS: Chicken HD11 macrophages were treated with GA (0, 12.5, 25, 50, 100, 200, 400, or 800 µg/ml) and lipopolysaccharide (LPS, 500 ng/ml) for 3, 6, 12, 24, or 48 h. Evaluated responses included phagocytosis, bacteria-killing, gene expression of cell surface molecules (cluster of differentiation 40 (CD40), CD80, CD83, and CD197) and antimicrobial effectors (inducible nitric oxide synthase (iNOS), NADPH oxidase-1 (NOX-1), interferon-γ (IFN-γ), LPS-induced tumor necrosis factor (TNF)-α factor (LITAF), interleukin-6 (IL-6), and IL-10), and production of nitric oxide (NO) and hydrogen peroxide (H2O2). RESULTS: GA increased the internalization of both fluorescein isothiocyanate (FITC)-dextran and ST by HD11 cells and markedly decreased the intracellular survival of ST. We found that the messenger RNA (mRNA) expression of cell surface molecules (CD40, CD80, CD83, and CD197) and cytokines (IFN-γ, IL-6, and IL-10) of HD11 cells was up-regulated following GA exposure. The expression of iNOS and NOX-1 was induced by GA and thereby the productions of NO and H2O2 in HD11 cells were enhanced. Notably, it was verified that nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) pathways were responsible for GA-induced synthesis of NO and IFN-γ gene expression. CONCLUSIONS: Taken together, these results suggested that GA exhibits a potent immune regulatory effect to activate chicken macrophages and enhances Salmonella-killing capacity.

Effects of equol on H2O2-induced oxidative stress in primary chicken intestinal epithelial cells.

This experiment investigated the antioxidant effects of equol on oxidative stress induced by H2O2 in chicken intestinal epithelial cells (IEC). IEC, from Lingnan yellow broiler chick embryos at embryonic day 18, were cultured in Dulbecco's modified Eagle's medium/F12. Cells were pretreated with 0, 10, 100, or 500 nM equol for 24 h before exposure to 300 µM H2O2 during a further 24 h. Oxidative damage was assessed by photomicrographs of cells, measuring cell proliferation, malondialdehyde (MDA) content, and antioxidative capacity from cellular total superoxide dismutase (T-SOD) activity, as well as the relative expressions of Nrf2, Bcl-2, SOD-1, GSH-Px3, Claudin-1 Treatment with 300 µM H2O2 caused serious damage to cells, with fewer normal intestinal epithelial cells, revealed by photomicroscopy. Treatment with 300 µM H2O2 significantly decreased live cell numbers compared with controls and prior treatment with equol had no effect in offsetting this action of H2O2 (P > 0.05). Compared with the cells treated just with H2O2, pre-treatment with 10, 100 and 500 nM equol significantly enhanced T-SOD activity (P < 0.05), while 10 and 100 nM equol before H2O2 significantly enhanced T-SOD activity compared with the untreated controls (P < 0.05). In cells pre-treated with 100 nM equol, the relative abundance of Nrf2 transcripts increased from the controls (P < 0.05) but expressions of Bcl-2, GSH-Px3, or SOD-1 were unaffected (P > 0.05). Pre-treatment with 10 and 100 nM equol significantly increased the transcript abundance of Claudin-1 (P < 0.05). Equol is shown here to protect IECs from oxidative damage by promoting the expression of antioxidant genes, increasing the activities of antioxidant enzymes, and by enhancing antioxidant capacity; 100 nM equol appeared to be the most effective concentration.

Consumption of Oxidized Soybean Oil Increased Intestinal Oxidative Stress and Affected Intestinal Immune Variables in Yellow-feathered Broilers.

This study investigated the effect of oxidized soybean oil in the diet of young chickens on growth performance and intestinal oxidative stress, and indices of intestinal immune function. Corn-soybean-based diets containing 2% mixtures of fresh and oxidized soybean oil provided 6 levels (0.15, 1.01, 3.14, 4.95, 7.05, and 8.97 meqO2/kg) of peroxide value (POV) in the diets. Each dietary treatment, fed for 22 d, had 6 replicates, each containing 30 birds (n = 1,080). Increasing POV levels reduced average daily feed intake (ADFI) of the broilers during d 1 to 10, body weight and average daily gain at d 22 but did not affect overall ADFI. Concentrations of malondialdehyde (MDA) increased in plasma and jejunum as POV increased but total antioxidative capacity (T-AOC) declined in plasma and jejunum. Catalase (CAT) activity declined in plasma and jejunum as did plasma glutathione S-transferase (GST). Effects were apparent at POV exceeding 3.14 meqO2/kg for early ADFI and MDA in jejunum, and POV exceeding 1.01 meqO2/kg for CAT in plasma and jejunum, GST in plasma and T-AOC in jejunum. Relative jejunal abundance of nuclear factor kappa B (NF-κB) P50 and NF-κB P65 increased as dietary POV increased. Increasing POV levels reduced the jejunal concentrations of secretory immunoglobulin A and cluster of differentiation (CD) 4 and CD8 molecules with differences from controls apparent at dietary POV of 3.14 to 4.95 meqO2/kg. These findings indicated that growth performance, feed intake, and the local immune system of the small intestine were compromised by oxidative stress when young broilers were fed moderately oxidized soybean oil.

Equol Inhibits LPS-Induced Oxidative Stress and Enhances the Immune Response in Chicken HD11 Macrophages.

BACKGROUND/AIMS: There has been increasing recent attention on the antioxidative capacity of equol. This study tested the effect of equol on oxidative stress induced by lipopolysaccharide (LPS) and regulation of immunity in chicken macrophages. METHODS: Chicken HD11 macrophages were challenged with LPS (100 ng/mL) alone or with LPS (100 ng/mL) and (±)equol (10, 20, 40, 80, 160 µmol/L) together for 24h. Evaluated responses included the contents of malondialdehyde (MDA) and reduced glutathione (GSH), activities of total superoxide dismutase (T-SOD) and inducible nitric oxide synthase (iNOS), transcript abundance of superoxide dismutase 2 (SOD2), catalase (CAT), glutathione transferase (GST), Toll-like receptor 4 (TLR4), tumor necrosis factor alpha (TNFα) and interleukin-1 beta (IL-1ß), and contents of the cytokines TNFα, IL-1ß, interleukin-2 (IL-2) and interferon beta (IFNß). RESULTS: Exposure to LPS induced oxidative stress as contents of MDA increased and GSH decreased in LPS-treated cells (P < 0.05) compared to those in control cells. Compared to LPS alone, co-treatment with equol (20 µmol/L, 40 µmol/L or 80 µmol/L) reduced contents of MDA and increased those of GSH (both P < 0.05). Activity of T-SOD increased (P < 0.05) in cells treated with the higher contentration of equol (80 µmol/L or 160 µmol/L), however, all concentrations (20 µmol/L to 160 µmol/L) increased activity of iNOS (P < 0.05). The highest concentration of equol (160 µmol/L) increased SOD2 and GST transcripts (P < 0.05). Equol treatment increased transcripts of TLR4, TNFα and IL-1ß (P < 0.05). And there were similar changes in contents of IL-1ß, IL-2, IFNß and TNFα in the cells (P < 0.05). CONCLUSIONS: It concluded that equol can protect chicken HD11 macrophages from oxidative stress induced by LPS through reducing lipid peroxidation products and enhancing contents of antioxidants, and activities of relevant antioxidase enzymes; effects were also seen in gene expression related to the immune response and increased contents of cytokines. The optimal concentration of equol on antioxidation and immune enhancement in chicken macrophages was 40 µmol/L.

Effects of dietary selenomethionine supplementation on growth performance, meat quality and antioxidant property in yellow broilers.

This study was conducted to investigate the effects of dietary selenomethionine (Se-Met) supplementation on growth performance, meat quality and antioxidant property in male broilers. A total of 800 43-day-old Lingnan yellow male broilers were randomly allotted to 5 dietary treatments with four replicates of 40 birds for a period of 3 weeks ad libitum. Final BW and weight gain of birds significantly increased by Se-Met supplementation at the 0.225 mg/kg level (P < 0.05). The addition of Se-Met significantly decreased drip loss, lightness value, and elevated pH value of meat (p < 0.05). Adding sodium selenite (SS) only increased pH value of meat (p < 0.05). In plasma, supplemental Se-Met at 0.225 mg/kg level increased total antioxidant capability (T-AOC), glutathione peroxidase (GPX), total superoxide dismutase (T-SOD), catalase (CAT) activities, glutathione (GSH) concentration (p < 0.05), and decreased malondialdehyde production (p < 0.05), compared with the control and broilers fed SS diet. In breast muscle, the addition of Se-Met significantly elevated T-AOC, GPX, T-SOD, CAT activities, contents of metallothionein and GSH (p < 0.05), and reduced carbonyl protein content (p < 0.05). While compared with broilers fed SS diet, supplemental 0.225 mg/kg Se-Met increased T-AOC, GPX, CAT activities, and GSH content (p < 0.05). Therefore, dietary Se-Met supplementation could improve growth performance and meat quality by enhancing antioxidative capacity in broilers compared with SS.