Effect of iron glycine chelate supplementation on egg quality and egg iron enrichment in laying hens

This study was conducted to evaluate the effects of iron glycine chelate (Fe-Gly) on egg quality of laying hens. A total of 810 laying hens (HyLine Variety White, 26 wk old) were randomly assigned to 6 groups, and each group consisting of 135 hens (5 replicates of 27 hens each). Hens in the control group received a diet supplemented with 60 mg Fe/kg as FeSO4, whereas hens in the other 5 groups received diets supplemented with 0, 20, 40, 60, and 80 mg Fe/kg from Fe-Gly, respectively. The study showed that dietary Fe-Gly treatments influenced (P < 0.05) the internal egg quality (egg weight, Haugh unit, albumen height), compared with the control group. However, dietary Fe-Gly supplementation showed few effects on the ultrastructure of eggshell in this study. The group of 60 mg Fe/kg as Fe-Gly was promoted (P < 0.05) in succinate dehydrogenase levels of liver and spleen compared with the 0 mg Fe-Gly/kg group, whereas the control (Fe/kg as FeSO4) group has no differences compared with the 0 mg Fe-Gly/kg group. The concentrations of Fe in the eggshell, yolk, and albumen were increased with increasing concentrations of Fe-Gly, where Fe-Gly (60, 80 mg Fe/kg) had higher (P < 0.01) Fe concentration than the control in yolk and albumen. The Fe-Gly groups (60, 80 mg Fe/kg) were influenced (P < 0.05) in transferrin, divalent mental transport 1, and ferroportin 1, compared with the control (FeSO4). In conclusion, Fe-Gly (60 mg Fe/kg) improved egg quality and egg iron enrichment. In general, there were no significant differences between Fe-Gly (40) and the control group in albumen height, Haugh unit, Fe concentration in eggshell and yolk. It revealed that FeSO4 could be substituted by a lower concentration of Fe-Gly and Fe-Gly may be superior to FeSO4 for egg quality in laying hens.

Excess dietary fluoride affects laying performance, egg quality, tissue retention, serum biochemical indices, and reproductive hormones of laying hens

The present study aimed to evaluate the effects of excess dietary fluoride (F) on laying performance, egg quality, tissue retention, serum biochemical indices, and serum reproductive hormones of laying hens. A total of 384 Hy-Line Gray hens, 37 wk old, were treated with sodium fluoride added to a corn-soybean meal basal diet at 0, 400, 800, and 1200 mg fluorine/kg feed. The results showed that dietary F levels at 800 and 1200 mg/kg markedly decreased ADFI, laying rate, average egg weight, and increased feed conversion ratio (FCR) (P < 0.05). Dietary F levels at 800 and 1200 mg/kg dramatically decreased the egg quality of albumen height, yolk color, eggshell strength, and eggshell thickness, and on the 49th D, 400 mg/kg F group significantly decreased the eggshell strength, compared to those of control group. Fluoride residues in tissues of hens were increased significantly with the increase of dietary F supplemental levels (P < 0.05). Fluoride concentrations were generally high in feces, eggshell, tibia, kidney, and ovary, and the highest in feces, following with eggshell and tibia, lower in kidney and ovary, and the lowest in serum. Serum uric acid levels and alanine aminotransferase activity increased significantly (P < 0.05), and glucose, triglycerides, and phosphorus decreased significantly (P < 0.05) in response to dietary F concentration, compared to those of the control group, respectively. Dietary F supplementation at 1200 mg/kg significantly decreased (P < 0.05) the estrogen concentrations in serum, compared to those of the control group. Concentrations of progesterone in the fluoride-treated groups were significantly (P < 0.05) decreased relative to those of the control group. In conclusion, these results indicated that the excessive ingestion of F has had a detrimental effect on egg laying rate and quality of eggs by damaging the function of the liver, kidney, and ovary of laying hens.

POMC gene expression, polymorphism, and the association with reproduction traits in chickens

Reproduction trait is one of the most important economic traits in poultry industry. This study was aimed to investigate the mRNA expression levels, single nucleotide polymorphisms (SNP) of POMC gene, and the association with reproduction traits in chickens. Five SNP (g.958 G > A, g.1374 G > C, g.1393 G > A, g.1817 C > T, and g.1918G > A) were detected in introns of POMC gene in 317 Zhenning yellow chickens. Association analysis revealed that g.958 G > A and g.1817 C > T showed significantly associations with fertilization rate, hatching rate of hatching eggs, and hatching rate of fertilized eggs in chickens. Simultaneously, g.1374 G > C and g.1918G > A were both associated with egg weight at 300 D of age (P < 0.05). The SNP of g.958 G > A, g.1393 G > A, and g.1817 C > T were all associated with E2 hormone levels (P < 0.05). The result of mRNA expression levels in different tissues showed that POMC mRNA expression level in the pituitary was higher than those in the other tissues and varied in different genotypes. In conclusion, the results in this study provided new evidences that polymorphisms of the POMC gene have potential effects on reproduction traits in chickens. The 5 SNP detected in this study could be potential markers for improving reproduction traits in chickens.

[Clinical study on factor Ⅷ inhibitor in children with hemophilia A]

目的

探讨血友病A（HA）患儿凝血因子Ⅷ（FⅧ）抑制物产生的相关因素及抑制物产生前后出血与关节病表现的差异。

方法

对2015年1月至2018年8月河南省血友病管理中心登记收治的381例16岁以下HA患儿进行回顾性分析。

结果

381例HA患儿中，轻型116例（30.4%），中间型196例（51.4%），重型69例（18.1%）。FⅧ抑制物阳性患者54例（14.2%），高滴度、低滴度分别为22、32例。血友病家族史与FⅧ抑制物阳性相关[P<0.001，OR=3.299（95%CI 1.743~5.983）]；高强度暴露与FⅧ抑制物的产生相关[P=0.002，OR=2.587（95%CI 1.414~4.731）]。高强度暴露与高滴度FⅧ抑制物产生相关[P=0.001，OR=8.689（95%CI 2.464~30.638）]。54例HA患者产生抑制物后，总体关节年出血率、创伤性年出血率增加（z=−3.440，P=0.001；z=−2.232，P=0.026），而非关节年出血率、自发性年出血率与抑制物产生前比较差异无统计学意义（z=−1.342，P=0.180；z=−1.414，P=0.157）。关节超声评分较产生抑制物前差异无统计学意义（z=−0.632，P=0.527）。

结论

血友病家族史、高强度暴露可增加HA患儿发生FⅧ抑制物的风险，且高强度暴露可增加HA患者出现高滴度抑制物的风险。

Effects of parental dietary linoleic acid on growth performance, antioxidant capacity, and lipid metabolism in domestic pigeons (Columba livia)

The objective of this study was to evaluate the effects of dietary linoleic acid (LA) on growth performance, antioxidant capacity, and lipid metabolism in pigeon squabs by supplementing LA in their parental diets. A completely randomized design that consisted of a control group, 1% dietary LA addition group (LA1%), 2% dietary LA addition group (LA2%), and 4% dietary LA addition group (LA4%) was used. Six squabs from each treatment were randomly sampled at the day of hatch and days 7, 14, and 21 after hatch. The results showed that parental dietary LA had no significant influence (P > 0.05) on body weight (BW) gain or relative organ weights (% of BW) in squabs. The activities of superoxide dismutase, catalase, and glutathione peroxidase in the LA1% were significantly increased (P < 0.05) compared with those in the control group. The malondialdehyde content in the LA1% was significantly lower (P < 0.05) than that in the control group. The levels of serum triglyceride in the LA1% and LA2% were significantly decreased (P < 0.05) compared with those in the control group, whereas the serum high-density lipoprotein cholesterol level in the LA1% and LA2% and the free fatty acid level in the LA4% were significantly higher (P < 0.05) than those of the control group. The activities of lipoprotein lipase, hepatic lipase, and hormone-sensitive lipase in the LA1% were significantly higher (P < 0.05) than those in the control group. The 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in the LA1% and the hormone-sensitive lipase activity in the LA4% were significantly decreased (P < 0.05) compared with those in the control group. The mRNA expression of carnitine palmitoyltransferase 1, acyl-CoA 1, and peroxisome proliferator-activated receptor α was significantly upregulated (P < 0.05) in the LA1% compared with that in the control group. The Oil Red O staining area in the LA1% and LA2% was significantly reduced compared with that in the control group. The results indicated that although supplemental LA had negligible effects on growth and development in pigeon squabs, parental dietary LA at a concentration of 1% could have beneficial effects on maintaining squabs healthy as reflected by improved antioxidant capacity and lipid metabolism.

[Effects of Akkermansia muciniphila on the Proliferation, Apoptosis and Insulin Secretion of Rat Islet Cell Tumor Cells]

Objective

To investigate the effects of Akkermansia muciniphila ( A. muciniphila) on the proliferation, apoptosis and insulin secretion of rat pancreatic islet cell tumor cells (INS-1).

Methods

INS-1 cells were divided into three groups, normal, repair, and protect groups, and subsequently every group was subjected with A. muciniphila metabolites, live A. muciniphilaorpasteurized A. muciniphila for 48 h. A group that did not treat with anything was set as blank control. After intervention, the cell viability was determined by MTT method, the insulin secretion level stimulated by glucose was determined by ELISA, the expressions of the genes involved in insulin secretion and apoptosis were tested by qRT-PCR, and the expression of apoptosis related protein Bax was evaluated by Western blot.

Results

There was no significant change in INS-1 cell morphology after co-incubation with 3 types of A. Muciniphila interventions for 48 h. The proliferative activity of INS-1 cells was decreased in the repair group that treated with live A. muciniphila than that of control ( P<0.005). A. muciniphila intervention had no effect on insulin secretion in INS-1 cells in normal, repair or protection group ( P>0.05). A. muciniphila secretions promoted the expression of glucose transporter 2 ( Glut2) in 3 groups and the expression of glucokinase ( GCK) in repair group ( P<0.05). The expression of Baxof the INS-1 cell in the normal group was decreased after intervented with 3 kinds of A. muciniphila intervention materials ( P<0.001).The expression of Bax gene of the INS-1 cell in the repair group that treated with dead A. muciniphilawas decreased ( P<0.05). The expression of Bax protein of INS-1 cells that treated with A. muciniphila interventions was decreased.

Conclusion

A. muciniphila can promote the expression of insulin secretion-related genes in INS-1 cells, inhibit the expression of apoptotic genes and apoptosis protein Bax.This research provides a new direction for applying A. muciniphila in improving type 2 diabetes.

Effects of in ovo feeding of L-lysine on hatchability, hatching time, and early post-hatch development in domestic pigeons (Columba livia)1

This study was conducted to evaluate the effects of in ovo feeding (IOF) of L-lysine (Lys) on hatchability and development in pigeon neonates. At day 13 of incubation, fertile eggs were injected with 200 μL of sterilized saline (0.75%, SC group), 1% Conc. Lys solution (Lys group, 2.11 mg Lys dissolved in 200 μL of sterilized saline), with controls not injected (NC group). The results showed that IOF of Lys decreased the hatchability (P < 0.05) compared with other groups, whereas the hatching time was not affected among groups. On day 14 of post-hatch (D14), the body weight (BW) of squabs received Lys IOF was increased relative to the NC group (P < 0.05). Squabs in Lys group exhibited higher (P < 0.05) body weight gain (BWG) than other groups from D14 to day of hatch (DOH). Meanwhile, IOF of Lys increased the brain relative weight on DOH (P < 0.05), and organ index of heart, legs, and gizzard on day 7 of post-hatch (D7) compared with other groups. In addition, the length index of duodenum, jejunum, or ileum had no difference between groups, as well as the weight index except the weight index of duodenum in Lys group was higher than that of SC group on DOH. However, squabs received Lys IOF showed lower villus height, crypt depth, and villus surface area of jejunum than NC group (P < 0.05) on DOH, and lower crypt depth than NC and SC groups on D7. The situation was improved by D14, although there was no significant difference in morphometric trait of jejunum between Lys group and NC group, squabs received Lys IOF showed higher villus height, crypt depth, and villus surface area of jejunum than NC group. In conclusion, the present study demonstrates that IOF of Lys has negative effects on hatchability and development of early post-hatch squabs, but the situation will be improved with the growth of age.

Expression of MSTN gene and its correlation with pectoralis muscle fiber traits in the domestic pigeons (Columba livia)

Myostatin (MSTN) is a negative regulator of skeletal muscle growth and plays an important role in muscle development. In this research, we constructed a tissue expression profile of the pigeon MSTN gene in eight tissues and a spatio-temporal expression profile in the pectoral muscle using qRT-PCR method. And the pectoralis muscle fiber traits during pigeon post-hatching stages at 1, 7, 14, 21, and 28 D were analyzed through the paraffin sections. Then the correlations between the muscle fiber diameter, cross-sectional area, density, and the expression of MSTN in the pectoral muscle were analyzed. Results showed that MSTN mRNA was mainly expressed in breast muscle, heart, spleen, and kidney and it was almost unexpressed in the liver and lungs. Moreover, the MSTN mRNA expression level in breast muscle was significantly higher than that in other tissues (P < 0.05), and showed an interesting trend that it decreased in the first week and then increased with age. Meanwhile, decrease of myostatin transcripts was accompanied by the down-regulation of Myf5 and the up-regulation of MyoG during the first week post-hatching. In addition, the paraffin sections analysis results revealed that the diameter and cross-sectional area of pectoralis muscle fiber significantly increased with age (P < 0.05), and a significant positive correlation was shown between the MSTN gene expression level and muscle fiber diameter (P < 0.05). These fundamental researches might contribute to further understanding of the roles MSTN played in the post-hatching muscle fiber development in pigeon.

[Risk factor analysis on anastomotic leakage after laparoscopic surgery in rectal cancer patient with neoadjuvant therapy and establishment of a nomogram prediction model]

Objective: To investigate the risk factors of anastomotic leakage (AL) after laparoscopic surgery in rectal cancer patient with neoadjuvant therapy and construct a nomogram prediction model. Methods: This study was a retrospective case-control study that collected and reviewed the clinicopathological data of 359 patients who underwent laparoscopic surgery from January 2012 to January 2018, including 202 patients from the Department of General Surgery, Nanfang Hospital of Southern Medical University and 157 patients from the Department of Gastrointestinal Surgery of Fujian Provincial Cancer Hospital. Inclusion criteria: (1) age ≥ 18 years old; (2) diagnosis as rectal cancer by biopsy before treatment; (3) distance from tumor to anus within 12 cm; (4) locally advanced stage (T3-T4 or N+) diagnosed by imaging (CT, MRI, PET or ultrasound); (5) standardized neoadjuvant therapy followed by laparoscopic radical operation. Exclusion criteria: (1) previous history of colorectal cancer surgery; (2) short-term or incomplete standardized neoadjuvant therapy; (3) Miles, Hartmann, emergency surgery, palliative resection; (4) conversion to open surgery. Clinicopathological data, including age, gender, body mass index (BMI), preoperative albumin, distance from tumor to anus, operation hospital, American Society of Anesthesiologists score (ASA score), operation time, T stage, N stage, M stage, TNM stage, pathological complete response (pCR) were analyzed with univariate analysis to identify predictors for AL after laparoscopic surgery in rectal cancer patient with neoadjuvant therapy. Then, incorporated predictors of AL, which were screened by multivariate logistic regression, were plotted by the "rms" package in R software to establish a nomogram model. According to the scale of the nomogram of each risk factor, the total score could be obtained by adding each single score, then the corresponding probability of postoperative AL could be acquired. The area under ROC curve (AUC) was used to evaluate the predictive ability of each risk factor and nomogram on model. AUC > 0.75 indicated that the model had good predictive ability. The Bootstrap method (1000 bootstrapping resamples) was applied as internal verification to show the robustness of the model. The discrimination of the nomogram was determined by calculating the average consistency index (C-index) whose rage was 0.5 to 1.0. Higher C-index indicated better consistency with actual risk. The calibration curve was used to assess the calibration of prediction model. The Hosmer-Lemeshow test yielding a non-significant statistic (P>0.05) suggested no departure from the perfect fit. Results: Of 359 cases, 224 were male, 135 were female, 189 were ≥ 55 years old, 98 had a BMI > 24 kg/m(2), 176 had preoperative albumin ≤ 40 g/L, 128 had distance from tumor to anus ≤ 5 cm, 257 were TNM 0-II stage, 102 were TNM III-IV stage, and 84 achieved pCR after neoadjuvant therapy. The incidence of postoperative AL was 9.5% (34/359). Univariate analysis showed that gender, preoperative albumin and distance from tumor to the anus were associated with postoperative AL (All P<0.05). Multivariate logistic regression analysis revealed that male (OR=2.480, 95% CI: 1.012-6.077, P=0.047), preoperative albumin ≤40 g/L (OR=5.319, 95% CI: 2.106-13.433, P<0.001) and distance from tumor to anus ≤ 5 cm (OR=4.339, 95% CI: 1.990-9.458, P<0.001) were significant independent risk factors for postoperative AL. According to these results, a nomogram prediction model was constructed. The male was for 55 points, the preoperative albumin ≤ 40 g/L was for 100 points, and the distance from tumor to the anus ≤ 5 cm was for 88 points. Adding all the points of each risk factor, the corresponding probability of total score would indicated the morbidity of postoperative AL predicted by this nomogram modal. The AUC of the nomogram was 0.792 (95% CI: 0.729-0.856), and the C-index was 0.792 after internal verification. The calibration curve showed that the predictive results were well correlated with the actual results (P=0.562). Conclusions: Male, preoperative albumin ≤ 40 g/L and distance from tumor to the anus ≤ 5 cm are independent risk factors for AL after laparoscopic surgery in rectal cancer patient with neoadjuvant therapy. The nomogram prediction model is helpful to predict the probability of AL after surgery.

Effects of in ovo injection of L-histidine on hatch performance and post-hatch development in domestic pigeons (Columba livia)

The objective of this study was to evaluate the effects of in ovo injection of histidine on hatch performance and post-hatch development by determining hatchability, hatching time, BW gain, carcass traits, and intestinal morphology in domestic pigeons (Columba livia). A completely randomized design (n = 3) with a L-histidine injection treatment (His group, 0.55 mg histidine dissolved in 200 μL 0.75% saline as 1% Conc compared to total histidine in the egg), a 0.75% saline injection treatment (SC group), and non-injection treatment (NC group) was used. Six squabs from each treatment were randomly sampled at day of hatch (DOH), day 7 (D7), and day 14 (D14) post hatch, respectively. Results showed that in ovo injection of histidine solution increased (P < 0.01) the hatchability in comparison with that of other groups. The hatching time of His group was earlier (P = 0.05) than that of the NC group. In ovo injection of histidine had no influence (P > 0.05) on BW gain and carcass traits, but had a significant effect on the organ index of pigeons. The index of pancreas on DOH, the indices of leg, gizzard, proventriculus, small intestine, and pancreas on D7, and the index of head on D14 were significantly increased (P < 0.05) by injection of histidine. Moreover, in ovo injection of histidine had significant effects on the weight indices of different intestinal segments and jejunal morphology in squabs. Ileum weight index on D7 from His group was significantly higher (P < 0.05) than that of other groups. Compared with the NC group, the jejunal crypt depth on DOH and D7 of His group decreased (P < 0.05), while jejunal villus area and villus crypt ratio on D7 of His group increased (P < 0.05). The results of this study indicate that in ovo injection of histidine may have beneficial effects on squabs' hatchability, intestinal development but have negligible effects on their growth performance during early post-hatch period.

Effects of in ovo injection of sulfur-containing amino acids on heat shock protein 70, corticosterone hormone, antioxidant indices, and lipid profile of newly hatched broiler chicks exposed to heat stress during incubation

This study hypothesizes that in ovo sulfur amino acids (SAA) injection can alleviate the heat or oxidative stress of hatched chicks. Thus, the study aimed to assess the impact of in ovo injection of SAA with heat stress during the incubation on heat shock protein 70 (HSP70), corticosterone hormone, antioxidant indices, and lipid profile of newly hatched broiler chicks. Eggs were incubated under optimal incubation temperature (37.8°C) from days 1 to 10 then under high temperature (39.6°C for 6 h daily) between 10 and 18 D of the incubation. At day 17.5 of incubation, 150 eggs were randomly divided into 3 groups of 50 replicate eggs. The first group served as control (non-injected group, NIG), the second group was only injected with saline solution (saline-injected group, SIG), and the third group was injected with a mixture of 5.90 mg L-methionine plus 3.40 mg L-cysteine (sulfur amino acids-injected group, SAAIG). The results exhibited that serum HSP70 and corticosterone concentrations were significantly reduced (P < 0.001) in the SAAIG compared with the NIG and SIG. In ovo SAA injection significantly augmented the antioxidant indices in the serum and tissues compared with the NIG and SIG. HSP70 mRNA relative expression was decreased but glutathione peroxidase (GSH-Px) mRNA relative expression was augmented in the tested tissues (P < 0.001) in the SAAIG compared with the NIG. The SAAIG had significantly (P < 0.05) lower levels in serum lipid profile compared to those of the control and SIG. In conclusion, in ovo SAA injection (methionine plus cysteine) in the embryonated eggs exposed to heat stress increased GSH-Px gene expression and antioxidant indices, and reduced HSP70 gene expression, corticosterone concentrations, and lipid profile of newly hatched broiler chicks.

Effects of dietary supplementation with Clostridium butyricum on laying performance, egg quality, serum parameters, and cecal microflora of laying hens in the late phase of production

This experiment was conducted to evaluate the effects of dietary supplementation with Clostridium butyricum on laying performance, egg quality, serum parameters, and cecal microflora of laying hens in the late phase of production. Jinghong-1 strain laying hens (n = 960; 48 wk of age) were randomly allocated to 5 treatment groups with 6 replicates of 32 hens. Hens were fed with basal diet (control) and basal diet supplemented with 2.5 × 104 (CB1), 5 × 104 (CB2), 1 × 105 (CB3), and 2 × 105 (CB4) cfu/g C. butyricum for 10 wk. The results showed that egg production, egg mass, and eggshell strength increased quadratically as supplemental C. butyricum increased, and these responses were maximized in the CB2 group (P < 0.05). Compared with the control group, the addition of C. butyricum resulted in quadratic effects on serum total protein, uric acid, calcium, complement component C3 and catalase concentrations, and these responses were maximized or minimized in the CB2 group (P < 0.05). Linear and quadratic increases were observed in serum IgM, total superoxide dismutase, and glutathione peroxidase concentrations, and these responses were maximized in CB2 or CB3 group (P < 0.05). The addition of C. butyricum in the CB2 group resulted in linearly increasing levels of serum IgG concentration as compared with the control group (P < 0.05). Spleen index increased (P < 0.05) in the CB2 group. Hens fed with C. butyricum reduced (P > 0.05) the population of E. coli, while Bifidobacterium counts increased quadratically and maximized in the CB2 group (P < 0.05). In conclusion, the results indicated that dietary supplementation with C. butyricum (5 × 104 or 1 × 105 cfu/g) could improve laying performance and egg quality by promoting immune function, enhancing antioxidative capacity, and benefiting the cecal microflora of laying hens in the late phase of production.

[The clinical characteristics of immunocompetent adults with chronic active Epstein-Barr virus associated enteritis]

Objective: To investigate the clinical and pathological characteristics of chronic active Epstein-Barr virus associated enteritis (CAEAE) . Methods: The clinical data of 6 CAEAE patients in Peking Union Medical College Hospital were retrospectively analyzed from January 2010 to November 2017, including clinical manifestations, endoscopic, pathological features, medications and clinical outcome. Results: The male∶female ratio was 4∶2 and the average age was 34 years old. All patients did not have personal and family history of immunodeficiency. The common symptoms consisted of fever (6/6), abdominal pain (6/6), hematochezia (6/6) and diarrhea (5/6). The most frequently affected sites were colorectum (5/6), followed by small intestine (3/6). Further serologic tests revealed a high load of serum Epstein-Barr virus(EBV) DNA. The main manifestations under endoscopy were multifocal or diffuse irregular ulcers. There was inflammation in the ulcer bases and surrounding areas, where EBV-encoded small RNA (EBER) was positive by in situ hybridization (6/6). The common complications were massive hemorrhage (3/6) and intestinal perforation (2/6). None of treatment agents including glucocorticoid, ganciclovir, foscarnet sodium and cytotoxic drugs was effective. All patients died within 0.5 to 13 months after diagnosis. Conclusions: CAEAE in immunocompetent individuals is a rare disorder with poor prognosis. It is difficult to differentiate CAEAE from inflammatory bowel disease due to similar clinical and endoscopic manifestations.

Effects of rearing systems on reproductive hormones secretion and their receptors gene expression in Xianju chickens under summer conditions

Previous study in our lab showed that indigenous Xianju chickens from free-range system (FRS) under summer conditions had lower egg production than those from conventional cage rearing system (CRS). The objective of this study was to preliminarily determine the FRS-dependent mechanism of depressing laying performance according to determining the effect of rearing systems on reproductive hormones secretion and their receptors mRNA expression in Xianju chickens reared under summer conditions. A total of 360 indigenous Xianju chickens were randomly allocated to CRS and FRS groups, each of which included 5 replicates of 36 hens. The experiment lasted between 21 and 29 wk of age. We found that the ovarian weight, numbers of small yellow follicles, and large white follicles in the FRS group were lower than those in the CRS group (P < 0.05). Changing from CRS to FRS increased serum concentrations of prolactin and decreased serum-luteinizing hormone and progesterone levels (P < 0.05). Gene expressions in the preovulatory follicles from FRS hens were upregulated for prolactin receptor and downregulated for luteinizing hormone receptor and progesterone receptor, compared to those from CRS hens (P < 0.05). It can be concluded that changing from CRS to FRS in the current experimental conditions depressed egg production traits in Xianju chickens by inducing a synergistic activity of reproductive hormones and the gene expressions of their receptors.

Association of ADSL gene polymorphisms with meat quality and carcass traits in domestic pigeons (Columba livia)

1. Adenylosuccinate lyase (ADSL) plays an important role in the synthesis of inosine monophosphate (IMP). In this trial, a total of 200 pigeons were sampled and slaughtered. Seven meat quality traits and 11 carcass traits were measured. DNA sequencing was used to detect nucleotide mutations, and associations between ADSL gene polymorphisms and meat quality and carcass traits were analysed. 2. Sequencing results showed that 9 nucleotide mutations were found in the exons of the ADSL gene. All the mutations were synonymous except C13065G, which caused a change in amino acids (Ser to Arg). In addition, two of the detected single nucleotide polymorphisms (SNPs) had significant associations with meat quality and carcass traits. 3. For the C13065G SNP located in exon11, the IMP content of breast muscle in AA and AB genotype was higher than in the BB genotype (P < 0.01). The SNP G10696A located in exon10 was significantly associated with carcass rate, in which AA and AB genotype were higher than the BB genotype (P < 0.01). 4. The results indicated that the ADSL gene has a close association with meat quality and carcass traits in domestic pigeons, and G10696A and C13065G SNPs could be applied as genetic markers in molecular marker-assisted breeding of pigeons.

Effects of dietary L-arginine levels on small intestine protein turnover and the expression of genes related to protein synthesis and proteolysis of layers

The aim of this study was to test the effects of dietary L-arginine (Arg) levels on protein turnover in the small intestine and the expression of genes related to protein synthesis and proteolysis of laying hens. Xinyang Black commercial laying hens (n = 864, aged 217 d) were randomly distributed to 6 treatments with 4 replicates of 36 birds. The dietary treatments were corn-corn gluten meal based diets containing 0.64, 0.86, 1.03, 1.27, 1.42 and 1.66% L-Arg, respectively. Fractional protein synthesis rate (FSR) and fractional protein gain rate (FGR) in the jejunum were the highest in the 1.27% L-Arg group. The mRNA expression of target of rapamycin (TOR), ribosomal protein S6 kinase 1 (S6K1), and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) in the duodenum reached the highest in the 1.27% L-Arg group, while the mRNA expression of 20S proteasome (20S) was the lowest in the 1.27% L-Arg group. The mRNA abundances of TOR and S6K1 in the jejunum were the highest in the 1.27% L-Arg group, while the mRNA expression of 20S was the lowest in the 1.27% L-Arg group, and the protein expression and phosphorylation levels of TOR in the 1.27% L-Arg group were higher than those in the 0.64% L-Arg group. These results indicate that the action of an appropriate level of dietary L-Arg to improve the protein synthesis of the small intestine involves up-regulating the protein expression and phosphorylation level of TOR in the jejunum accompanied by inhibiting the mRNA expression of 20S of laying hens.

Effect of mercury chloride on oxidative stress and nuclear factor erythroid 2-related factor 2 signalling molecule in liver and kidney of laying hens

This study investigated the effects of mercury chloride (HgCl₂ ) on the deposition of mercury (Hg), histopathology and oxidative stress in liver and kidney of laying hens. The gene expressions of antioxidant enzymes and nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) were further studied to uncover the molecular mechanism. A total of 960 40-week-old Hyline brown laying hens were randomly allocated to five treatments with eight pens per treatment and 24 hens per pen. The hens were fed with five experimental diets containing graded levels of Hg at 0.270, 1.250, 3.315, 9.405 and 27.230 mg/kg respectively. Results revealed that both deposition of Hg and score of injury in liver and kidney were significantly increased as dietary Hg dosage up to 27.230 mg/kg diet. Deposition of Hg was positively related to score of injury in liver and kidney of laying hens. Besides, the activities of superoxidative dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GSH-Px), and glutathione (GSH) content all significantly decreased (p < 0.05), while malondialdehyde (MDA) content significantly increased (p < 0.05) after Hg exposure in liver and kidney of laying hens. In addition, positive relationships occurred between antioxidant enzyme activities and antioxidant enzyme gene expressions except between SOD activity and manganese superoxide dismutase (MnSOD) gene expression in liver. Meanwhile, Nrf2 gene expression was positively related to antioxidant gene expressions and negatively connected with Keap1 gene expression. Negative relationships occurred between Nrf2 and Keap1 protein levels in liver and kidney. In conclusion, Hg could dose-dependently damage liver and kidney and induced hepatic and renal oxidative stress by means of suppressing Nrf2-Keap1 signalling molecule in laying hens.

Intrauterine hyperglycemia exposure results in intergenerational inheritance via DNA methylation reprogramming on F1 PGCs

BACKGROUND

The existing reports about intergenerational or transgenerational effects of intrauterine hyperglycemia have included both intrauterine and postnatal metabolic exposure factors, while the impact of intrauterine hyperglycemia per se has not been assessed alone. A number of studies suggest DNA methylation reprogramming of gametes plays a crucial role in the metabolic inheritance, but it is unclear when and how DNA methylation patterns are altered when exposed to intrauterine hyperglycemia. In this study, we selected nondiabetic F1- and F2-gestational diabetes mellitus (GDM) male mice as founders to examine metabolic changes in the next generation and performed methylome sequencing of day 13.5 primordial germ cells (PGCs) from F1-GDM to explore the underlying epigenetic mechanism.

RESULTS

We found that intrauterine hyperglycemia exposure resulted in obesity, insulin resistance, and/or glucose intolerance in F2 male mice, but no metabolic changes in F3 male mice at 8 weeks. Using reduced representation bisulfite sequencing, we found DNA methylome of day 13.5 PGCs from F1-GDM fetuses revealed differently methylated genes enriched in obesity and diabetes. Methylation validation of the insulin resistance and fat accumulation gene Fyn showed a consistent hypomethylation status in F1 PGCs, F1 fetal testes, sperm from F1/C-GDM mice, and somatic cells from F2-GDM male mice. In contrast, no methylation alteration was observed in F2-GDM male germ cells and F3-GDM somatic cells.

CONCLUSION

We provide evidence that intrauterine hyperglycemia exposure per se contributes to intergenerational metabolic changes in the F2 but not F3 generation. And the aberrant DNA methylation reprogramming occurs as early as day 13.5 in PGCs of the F1 generation. Our findings suggest that intrauterine exposure alone is sufficient to cause the epigenetic inheritance in F2 offspring, and the epigenetic memory carried by DNA methylation pattern could be erased by the second wave of methylation reprogramming in F2 PGCs during fetal development.

Effects of rearing systems on laying performance, egg quality, and serum biochemistry of Xianju chickens in summer

The objective of this study was to compare the laying performance, egg quality, and serum biochemistry of hens maintained in conventional cage rearing system (CRS), flat net-rearing system (NRS), and free range system (FRS) under summer conditions. Indigenous Xianju chickens (n = 540) were randomly allocated into cages or pens of rearing system groups, within each system there were 5 replicates with 36 hens in each replicate. The experiment lasted between 21 and 29 wk of age. Hen-day egg production (P = 0.00) and egg mass (P = 0.00) were higher in the CRS but were similar in the NRS and FRS. Lowest egg weight (P = 0.02), yolk weight (P = 0.00) and yolk ratio (P = 0.01), and feed intake (P = 0.01) were observed from the FRS, whereas lowest feed conversion ratio (FCR) was recorded from the CRS (P = 0.01). Rearing systems had negligible effect on egg quality. Serum Ca (P = 0.04) and total protein (P = 0.03) levels were found to be higher in the CRS but were lower in the FRS. Serum levels of glucose (P = 0.01), cholesterol (P = 0.00), and triglyceride (P = 0.00) in the CRS increased compared with the NRS and FRS groups, whereas serum levels of high density lipoprotein cholesterol (HDL-C; P = 0.01) in the CRS decreased. It can be concluded that under summer conditions, Xianju chickens from CRS had an advantage in terms of productivity parameters, but exhibited higher levels of serum lipids and glucose.

Effects of dietary threonine supplementation on intestinal barrier function and gut microbiota of laying hens

The effects of supplemental dietary threonine (Thr) on laying performance, expression of intestinal mucin 2 (MUC2) and secretory IgA (sIgA), and intestinal microbiota of laying hens fed a low CP diet were investigated. A total of 240 Lohmann Brown laying hens, 28 wk of age, was allocated to 3 dietary treatments, each of which included 5 replicates of 16 hens. Hens were fed a control diet (16% CP), a low CP diet (14% CP), or a low CP diet supplemented with 0.3% L-Thr for 12 weeks. Chemical analyses of the diets for Thr are 0.49, 0.45, and 0.69%, respectively. Lowering dietary CP impaired egg production and egg mass of laying hens. Dietary Thr supplementation to the low CP diet increased (P < 0.05) egg production and egg mass. In addition, ileal sIgA contents and MUC2 and sIgA mRNA expression were increased (P < 0.05) by dietary Thr addition. Dietary CP reduction reduced (P < 0.05) intestinal bacterial diversity, whereas dietary Thr supplementation to the low CP diet recovered the bacteria diversity and significantly increased the abundance of potential beneficial bacteria. In conclusion, dietary Thr supplementation to a low CP diet could affect intestinal health and hence productivity via regulating intestinal mucin and sIgA expression, and microbial population of laying hens.

Effects of in ovo feeding of l-arginine on hatchability, hatching time, early posthatch development, and carcass traits in domestic pigeons (Columba livia)

The objective of this research was to test the hypothesis that in ovo feeding of arginine (Arg) may improve hatchability and posthatch performance in domestic pigeons (). A completely randomized design ( = 3) with an Arg feeding treatment (Arg group, 1.14 mg Arg dissolved in 200 μL of 0.75% NaCl buffered saline as 1% concentration compared to total Arg in the egg), a buffered saline feeding treatment (SC group, 7.5 g NaCl dissolved in 1 L sterile distilled water as the concentration of poultry physiological saline), and a nonfeeding treatment (NC group) was used. Six squabs from each treatment were randomly sampled on day of hatch (DOH), posthatch d 7 (D7), and posthatch d 14 (D14), respectively. Hatchability, hatch time, BW, organ development, and carcass traits were examined. Results showed that in ovo feeding of the Arg solution increased ( < 0.05) the hatchability and advanced ( < 0.05) the hatching time in comparison with those of the other groups. Body weight of pigeon squabs that received Arg in ovo feeding was heavier ( < 0.05) on DOH and D14 than that of the NC group, and a greater ( < 0.05) BW gain from DOH to D14 and D7 to D14 was observed. Three clusters of 12 organs were classified according to the changes of organ indices. Squabs provided the Arg in ovo feeding treatment gained a priority in organ development. The heart index and gizzard index on D7 and the proventriculus index on D14 of squabs receiving Arg in ovo feeding were increased ( < 0.05) compared to those of the other groups. The brain index on DOH, the small intestine index and pancreas index on D7, and the liver index, pancreas index, and spleen index on D14 of squabs fed Arg were higher ( < 0.05) than those of the NC group. The spleen index on D7 and the small intestine index on D14 of squabs provided the Arg feeding treatment were enhanced ( < 0.05) compared with those of the SC group. The semieviscerated carcass weight of squabs receiving Arg was higher ( < 0.05) on D14 than that of other groups. The absolute weight of breast meat yield on D7 and breast meat yield percentage on D7 and D14 were improved ( < 0.05) in the Arg group compared with the NC group. The leg meat percentage on D7 and the carcass weight, eviscerated carcass weight, and absolute weight of breast meat yield on D14 were increased ( < 0.05) in the Arg group compared with those of the SC group. The results of this study indicate that in ovo feeding of pigeon embryos with Arg may have beneficial effects on squab hatch performance and early posthatch performance.

Association of DGAT2 gene polymorphisms with carcass and meat quality traits in domestic pigeons (Columba livia)

1. Diacylglycerol acyltransferase (DGAT) plays an important role in the synthesis of triacylglycerol, but its effects on meat quality and carcass composition in pigeons are unclear. In this study, single-nucleotide polymorphisms (SNPs) in the exons of the DGAT2 gene were identified and analysed by using DNA sequencing methods in 200 domestic pigeons (Columba livia). The associations between DGAT2 polymorphisms and carcass and meat quality traits were also analysed. 2. Sequencing results showed that 5 nucleotide mutations were detected in exons 3, 4, 5 and 6 of the DGAT2 gene. The analysis revealed three genotypes (AA, AB and BB) in G18398T and G22484C, in which the AA genotype and A allele had the highest frequency. 3. In the SNP of G18398T located in exon 5, individuals with genotype BB had significantly higher meat quality and lower abdominal fat content than those with AA or AB genotype. In the SNP of G22484C located in exon 6, the genotype AA showed highest carcass trait values, while the genotype BB represented better meat quality, compared to AA and AB genotypes. 4. The results imply that DGAT2 gene has a close relationship with carcass and meat quality traits in pigeons, and the SNPs of G18398T and G22484C can be used as genetic markers for marker-assisted breeding in pigeon.