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1. H-FABP (heart-type fatty acid-binding protein) is an important fatty acid-binding protein that participates in the metabolism and intracellular transportation of lipids. This study was designed ...

1. Fatty acid-binding proteins (FABP) are members of lipid-binding proteins, which participate in the metabolism and intracellular transportation of lipids. This study was designed to investigate t...

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 (P0.01) 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 (P0.05) 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 (P0.05) 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 (P0.05) than that of other groups. Compared with the NC group, the jejunal crypt depth on DOH and D7 of His group decreased (P0.05), while jejunal villus area and villus crypt ratio on D7 of His group increased (P0.05). 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.

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 (P0.05). 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 (P0.05). 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 (P0.05). The addition of C. butyricum in the CB2 group resulted in linearly increasing levels of serum IgG concentration as compared with the control group (P0.05). Spleen index increased (P0.05) in the CB2 group. Hens fed with C. butyricum reduced (P0.05) the population of E. coli, while Bifidobacterium counts increased quadratically and maximized in the CB2 group (P0.05). 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.

This study was to determine the effects of dietary Zn-methionine (Zn-Met) supplementation on the laying performance, egg quality, antioxidant capacity, and serum parameters of laying hens. Jingh ong-1 strain laying hens (n = 720, 49 wk of age) were randomly assigned to 6 treatments with 6 replications of 20 birds. The control was fed a basal diet supplemented with 80 mg of Zn/kg as Zn sulphate of diet and the 5 groups were fed a basal diet supplemented with 20, 40, 60, 80, and 100 mg of Zn/kg as Zn-Met of diet for 10 wk, respectively. At the terminal experiment, there were significant differences between control and 80 mg/kg Zn-Met group in feed intake (P0.05) and feed conversion ratio (FCR) (P0.01). Egg weight (P0.05) and albumen height (P0.01) reduced and were not significantly influenced by supplemental 80 mg/kg Zn-Met group until being stored 15 d as compared to the control. Zn-Met group in 100 mg/kg significantly increased haugh unit (P0.05) as compared to the control. The activity of MDA in serum had a linear decrease in 20 to 100 mg/kg Zn-Met. The activity of CAT in liver and GSH-Px in serum had quadratic effects in response to the Zn-Met treatments. Compared to the control, 60 mg/kg Zn-Met group increased the T-AOC, GSH-Px activity in serum (P0.01), and the T-AOC (P0.05), CuZnSOD (P0.01), GSH-Px (P0.01) activity in liver. Compared with the control, the concentration of serum ionic Ca in 80, 100 mg/kg Zn-Met treatments reduced (P0.01) significantly while the activity of serum alkaline phosphatase (AKP) increased in the Zn-Met groups of 40, 60, and 80 mg/kg (P0.01), and 100 mg/kg (P0.05). In conclusion, dietary Zn-Met supplementation at 60 to 80 mg/kg had more positive effects on performance, egg quality, and antioxidant capacity in laying hens as compared to 80 mg/kg ZnSO4.

The aim of this study was to explore the effects of early weaning on growth performance, intestinal morphology, digestive enzyme activity, antioxidant status, and cytokine status in domestic pigeon squabs (Columba livia). The conclusion is based on body weight (BW) and average daily gain (ADG), length index and weight index of small intestine, small intestinal morphology, activity of digestive enzymes in duodenum content, the concentrations of jejunal antioxidant status and cytokines. A completely randomized design with 2 treatments, the control group (CON) and early weaning (EW) group, was utilized. Eight squabs per treatment were sampled at the age of 25 d. The results showed that early weaning reduced BW (P < 0.05), ADG (P < 0.05), ileac length index (P < 0.05), and weight index (P < 0.01). Compared with the CON group, small intestinal morphology was altered in the EW group. Ileac crypt depth (CD) increased significantly (P < 0.01). The villus area was decreased in the duodenum (P < 0.05), jejunum (P < 0.01), and ileum (P < 0.05). The ileac ratio of villus height to crypt depth (VCR) in the EW group was lower than the ileac ratio of villus height to VCR in the CON group (P < 0.01). The activity of trypsin (P < 0.05), sucrase (P < 0.01) and aminopeptidase-N (APN) (P < 0.01) in the duodenum was reduced. Jejunal malondialdehyde (MDA) (P < 0.01) was increased and total superoxide dismutase (T-SOD) (P < 0.01) was reduced significantly. Early weaning decreased the concentrations of interferon-γ (IFN-γ) (P < 0.01), interleukin-4 (IL-4) (P < 0.05) and interleukin-10 (IL-10) (P < 0.01) but induced significant upregulation of interleukin-2 (IL-2) (P < 0.05). In conclusion, our results suggested that early weaning did harm the BW and ADG, intestinal length index and weight index, intestinal morphology, activity of digestive enzymes, and antioxidant and cytokine status.

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

The present study was conducted to determine the changes in concentrations of hormones and growth factors and their related receptor gene expressions in crop tissue, relative organ weight, and serum biochemical parameters in male and female pigeons during incubation and chick-rearing periods under artificial farming conditions. Seventy-eight pairs of 60-week-old White King pigeons with 2 fertile eggs per pair were randomly divided into 13 groups by different breeding stages. Serum prolactin and insulin-like growth factor-1 (IGF-1) concentrations in crop tissue homogenates were the highest in both male and female pigeons at 1 d of chick-rearing (R1), while epidermal growth factor (EGF) in female pigeons peaked at d 17 of incubation (I17) (P < 0.05). mRNA expression of the prolactin and EGF receptors in the crop tissue increased at the end of incubation and the early chick-rearing stage in both sexes. However, estrogen, progesterone, and growth hormone receptor expression each decreased during the early chick-rearing stage (P < 0.05). In male pigeons, IGF-1 receptor gene expression reached its peak at R7, while in female pigeons, it increased at the end of incubation. The relative weight of breast and abdominal fat in both sexes and thighs in the males was lowest at R7, and then gradually increased to the incubation period level. Serum total protein, albumin, and globulin concentrations increased to the highest levels at I17 (P < 0.05). Total cholesterol, triglyceride, and low-density lipoprotein reached their highest values at I17 in male pigeons and R25 in female pigeons (P < 0.05). In conclusion, hormones, growth factors, and their receptors potentially underlie pigeon crop tissue development. Changes in organs and serum biochemical profiles suggested their different breeding-cycle patterns with sexual effects.

Zn-doped In0.53Ga0.47As (100) β2 (2 × 4) photocathode surface is an important process for forming the performance of the negative electron affinity (NEA) photocathode. In this paper, the first-principles calculation is used based on the density functional theory (DFT) within scope of the generalized gradient approximation (GGA). The electronic and optical properties of zinc interstitial doped on five sites of In0.53Ga0.47As (100) β2 (2 × 4) photocathode surface are chosen and investigated. The band structure, density of state, dielectric function and absorption coefficient of zinc interstitial doping on In0.53Ga0.47As (100) β2 (2 × 4) photocathode surface are calculated. Results show that the zinc interstitial doping on In0.53Ga0.47As (100) β2 (2 × 4) photocathode surface makes energy band bend and some new energy bands are generated. The band gaps of zinc interstitial doping on In0.53Ga0.47As (100) β2 (2 × 4) surface are all becoming narrow. And it is beneficial for the formation of the NEA photocathode when zinc atom is interstitial doping at 1 position of In0.53Ga0.47As (100) β2 (2 × 4) photocathode surface, which researches dielectric constant and absorption coefficient. The theoretical calculations and analysis provide a guide for designing the near-infrared material.

This study was conducted to evaluate the effect of in ovo feeding of cationic amino acids on hatchability, hatch weights, and organ developments in pigeon squabs. Two experiments were conducted in this study. Eggs in Exp. 1 were subjected to modification of in ovo feeding in pigeons. Optimal time was determined by checking amniotic fluid volume, and suitable length was confirmed through ink injection. Results showed that the optimum time of in ovo feeding was on d 13 of embryonic development, and the suitable injected length was 20 mm to reach the amniotic cavity of the embryo. Eggs in Exp. 2 were transferred to access in ovo feeding of cationic amino acids. A total of 75 fertile pigeon eggs was randomly distributed into 5 treatments of 15 replicate eggs. Treatments in Exp. 2 consisted of non-injected controls (Control), a sterile buffered solution (0.75% saline), or a cationic amino acid mixture (> 98.5% purity crystalline L-arginine, > 98% purity crystalline L-lysine, and > 98.5% purity L-histidine) containing 0.1, 1, or 10% concentration (Conc.), which were relative to their total content in the eggs, respectively. The crystalline amino acids were dissolved in 200 μL buffered solution prior to in ovo feeding. After hatching, hatch weight (HW) and organ weight (OW) of the squabs were measured immediately. In ovo feeding of cationic amino acids increased the proportions of yolk-free hatch weight to hatch weight (YFHW/HW) (quadratic P = 0.01), and those of OW to YFHW including the heart (quadratic P = 0.01), kidney (quadratic P

This study was conducted to investigate the effects of dietary manganese-methionine (Mn-Met) supplementation on the egg quality of laying hens. A total of 480 Jinghong-1 strain layers aged 53 wk were divided into 5 groups with 6 replicates of 16 layers. Birds in the control group were fed a diet supplemented with 60 mg Mn/kg in the form of MnSO4; the birds in other 4 experimental groups were fed a diet supplemented with 20, 40, 60, and 80 mg Mn/kg as Mn-Met, respectively. Dietary Mn-Met treatments significantly affected (P 0.05) the albumen height, yolk color, and Haugh unit compared to those of the control diet. The Mn contents in the eggshell increased (P0.01) significantly by increasing the Mn-Met supplementation, whereas Mn content in eggshell was triple that in the yolk or albumen. Compared with the 60 mg/kg Mn-Met group, the transverse surface in the control group had (P 0.01) a greater width of mammillary cones, and there were obvious cracks on the outer surface in the control. There was no difference (P 0.05) in the eggshell gland (ESG) in the expression of calbindin-D28k (CaBP-D28k) mRNA in response to any diet treatment. In conclusion, dietary Mn-Met supplementation increased internal egg quality and the ultrastructure of the eggshell. Compared to the control, 60 mg/kg Mn-Met treatment resulted in improving egg quality, and 20 mg/kg Mn-Met treatment had similar effects the control treatment had on the egg quality. This indicates that the inorganic Mn can be replaced by the lower concentration of Mn-Met.

This study aimed to evaluate the hepatic glucose and lipid metabolism-related parameters of adult male and female White King pigeons (Columba livia) during incubation and chick rearing. At day 4 (I4), 10 (I10) and 17 (I17) of incubation and day 1 (R1), 7 (R7), 15 (R15) and 25 (R25) of chick rearing, livers were sampled from six pigeons for each sex. Glycogen and fat contents, activities of glycolytic enzymes (hexokinase, HK; 6-phosphofructokinase, 6-PFK), and genes expressions of key enzymes involved in glycolysis (pyruvate kinase, PK; glucokinase, GK), gluconeogenesis (phosphoenolpyruvate carboxykinase cytosolic, PCK1; fructose-1,6-bisphosphatase, FBP1; glucose-6-phosphatase, G6Pase), fatty acid synthesis (fatty acid synthase, FAS; acetyl-CoA carboxylase, ACC) and fatty acid β-oxidation (carnitine palmitoyltransferase 1, CPT1; acyl-CoA 1, ACO) were measured. In male and female pigeon livers, glycogen content and HK activity dramatically increased after I17 and after R1, respectively; expressions of FBP1 and G6Pase genes were maximized at R15; activity of 6-PFK and expressions of PK and CPT1 genes were highest at R7; fat content and expressions of FAS and ACC genes steeply increased from I10 to R1. In females, hepatic expressions of GK and PCK1 genes were greatest at R7 and I17, respectively; however, in males, both of them were maximized at R15. Hepatic expression of ACO gene was significantly enhanced at R1 compared to I17 and R7 in males, whereas it was notably up-regulated at I17 and R7 in females. Furthermore, expressions of PCK1, GK, FAS and ACC genes were in significant relation to fat content in the livers of female pigeons, while fat content in male pigeons was highly correlated with expression of PCK1, ACC, CPT1 and ACO genes. In conclusion, regulations of glucose and lipid metabolic processes were enhanced in parent pigeon livers from terminal phases of incubation to mid phase of chick rearing with sexual effects.

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.

The objective of this study was to investigate the effects of excess dietary fluoride (F) on laying performance and antioxidant capacity of laying hens. A total of 576 laying hens, 51 wk old, was randomly divided into 6 groups, each of which included 6 replicates of 16 hens. Graded amounts of sodium fluoride (NaF) were added to the basal diet to achieve concentrations of 16 (control), 200, 400, 600, 800, and 1,000 mg/kg F, respectively. Dietary F at 1,000 mg/kg significantly decreased ADFI, laying rate, and average egg weight, and increased feed conversion ratio (FCR) (P

1. The primary objective of this experiment was to estimate the toxic effects of arsenic (As) supplementation in feed on laying performance, As retention by eggs and organs, serum biochemical indices and endocrine hormones in laying hens. 2. A total of 320 "Jinghong Number 1" hens, 56-week-old, were randomly allocated into four treatments of four replicates with 20 layers in each. Graded arsenical was added to the basal diet in the experimental diets at As levels of 0, 17, 34 and 51 mg/kg, respectively. The trial lasted for 9 weeks including 1 week for acclimatisation. 3. Supplementation of dietary As for eight weeks had no effect on laying performance. As retention in albumen, yolk, egg, liver and kidney increased as As levels increased The level of serum phosphorus (P) was minimised at the 17 mg As/kg group. The activity of serum glutamic oxaloacetic transaminase (GOT) increased linearly. No differences were observed for levels of serum calcium (Ca), alkaline phosphatase (AKP) and serum glutamic pyruvic transaminase (GPT). Concentrations of estradiol (E

Ghrelin and cholecystokinin (CCK) are multifunctional peptides. In the current study, complete sequences of ghrelin (800 bp) and CCK (739 bp) were firstly cloned in Columba livia by using rapid amplification of cDNA ends (RACE) method. The open reading frames of ghrelin (351bp) and CCK (393bp) encoded 116 amino acids and 130 amino acids, respectively. Sequence comparison indicated that pigeon ghrelin and CCK shared high identity with those reported in other avian species. Quantitative real-time PCR analysis found that ghrelin and CCK mRNAs expressed in three intestinal segments of pigeon during development. Both ghrelin and CCK showed generally higher expressions at days posthatch than embryonic periods regardless of intestinal segments. In duodenum and ileum, the expressions of ghrelin and CCK mRNA reached the peak values at 8 d posthatch. Jejunum CCK mRNA level increased linearly after hatching, and reached the highest point at posthatch 28 d. Based on documented effects of long chain fatty acids (LCFAs) on pigeon ghrelin and CCK expression were also investigated in vitro. Higher concentrations (50 μM or 250 μM) of linoleic acid, α-linolenic acid or arachidonic acid can significantly increase ghrelin mRNA level in pigeon jejunum. However, for oleic acid, the induction of ghrelin gene expressions needed a lower concentration (5 μM). 5 μM of linoleic acid, α-linolenic acid or arachidonic acid and 250 μM palmitic acid repressed CCK expression significantly. A higher concentration (250 μM) of oleic acid or α-linolenic acid can up-regulate CCK mRNA level significantly. Our results indicated that ghrelin and CCK may act key functions in pigeon intestine development and their expressions could be regulated by LCFAs.

Xinyang green-shell laying hens (n = 720), 32 wk of age were allocated to 5 dietary treatments groups, each of which included 6 replicates of 24 hens. The control group was given a basal corn-peanut-soybean meal diet containing 0.47% L-threonine (L-Thr). L-Thr levels of the experimental groups were 0.57, 0.67, 0.77, and 0.87%, respectively. The trial lasted 10 wk. Serum concentrations of total superoxide dismutases (T-SOD) and superoxide dismutases (SOD) were maximized at 0.67% L-Thr group. The 0.57% L-Thr group had the highest serum total antioxidative capacity (T-AOC), while the 0.67% L-Thr group had the lowest serum malondialdehyde (MDA) concentration. Hens fed 0.67% L-Thr of the diet resulted in the highest SOD and T-AOC levels in the liver. The activity of amylase and lipase in the jejunum was maximized at 0.77% L-Thr level. Hens fed 0.77% L-Thr in the diet resulted in the highest IgM and IgG levels in the jejunum. In conclusion, we suggest that a L-Thr level above 0.67% may have had an antioxidant capacity and positive effect on digestive enzyme activities and antibody production in the jejunum of Xinyang green-shell laying hens.

Amino acids are considered to be anabolic factors that affect protein turnover. The aim of this study was to test the effects of dietary L-arginine (Arg) levels on protein metabolism in the liver of laying hens and the expression of genes related to protein synthesis and proteolysis. Xinyang black commercial laying hens (n = 864, 31 wk of age) were randomly allotted 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. Serum concentrations of total protein and albumin were maximized in the 1.27% L-Arg group, and serum concentration of urea acid was the lowest in the 1.27% L-Arg group. The 1.27% L-Arg group had the highest fractional protein synthesis rate and fractional protein gain rate in the liver. Consistent with the data on protein turnover, mRNA abundances of target of rapamycin (TOR) and ribosomal protein S6 kinase 1 increased in the liver of layers fed 1.27% L-Arg, while mRNA abundances of cathepsin B and 20S proteasome decreased at the same dietary L-Arg level. In conclusion, the dietary level of L-Arg increased the liver fractional protein synthesis rate and fractional protein gain rate of laying hens, and the action of an appropriate level of dietary L-Arg involves upregulating the gene expression of the TOR signaling pathway accompanied by suppressing the mRNA expression of cathepsin B and 20S proteasome in the liver.

The objective of this research was to examine the effects of prolactin (PRL) on the lipid synthesis of organ-cultured pigeon crops in vitro. In experiment 1, the histology, activities of enzymes, and expression of genes involved in metabolism and apoptosis of organ-cultured pigeon crops were analyzed over a 7-d culture period. The results showed that cultured crops maintained their structural integrity for up to 3 d in vitro. Beyond 3 d, caspase-3 activity and Bak1 gene expression increased with day of culture, whereas the activities of succinate dehydrogenase, Na+-K+-ATPase, Ca2+-Mg2+-ATPase, total ATPase, and gene expression of Bcl-2 and CK-19 diminished (P < 0.05). In experiment 2, the crops were cultured for 24, 36, and 48 h in medium containing 0, 25, or 50 ng/mL PRL, respectively, and the accumulation of lipid droplets, lipid content, and expression of fatty acid transportation- and lipogenesis-related genes were analyzed. The results showed that the crops with PRL supplements showed higher amounts of lipid droplets than those of the controls, and the droplets were mainly located in the basal nutritive layer in response to PRL. The efficacy of inducing lipid accumulation increased as the concentration of PRL increased. Crops with 50 ng/mL PRL incubated for 36 h displayed the maximal lipid content. Increasing the concentration of PRL from 0 to 50 ng/mL resulted in a dose-dependent increase in the expression of acetyl-CoA carboxylase, fatty acid synthase, fatty acid translocase, fatty acid binding protein 5, acyl-CoA binding protein, and peroxisome proliferator-activated receptor γ genes after incubation for 36 h (P < 0.05). Therefore, our results indicated that the organ-cultured pigeon crops maintained good viability for up to 3 d in vitro. Furthermore, PRL induced the lipid synthesis of organ-cultured pigeon crops in a dose- and time-dependent manner, which was related to the increased expression of genes involved in fatty acid transportation and lipogenesis.

The objective of this study was to test the hypothesis that in ovo injection of carbohydrates into pigeon (Columba livia) amnion may improve the small intestine development. At d 14.5 of incubation, 80 fertile eggs were injected with 200 μL of carbohydrate solution, and 80 control eggs were not injected. The carbohydrate solution (wt/vol) contained 2.5% maltose + 2.5% sucrose, all dissolved in 0.75% saline. Twelve eggs from each treatment were randomly sampled at d 16 of incubation and the day of hatch, embryos or young pigeons were euthanized, and the jejunum samples were collected. Jejunal villus surface area, activity of the brush border enzymes, sucrase, maltase, aminopeptidase-N, and alkaline phosphatase, and mRNA expression of the digestion-absorption related genes oligopeptide transporter 1, sodium glucose transporter 1, glucose transporter 2, aminopeptidase-N, and sucrase-isomaltase were examined. Results showed that in ovo injection of carbohydrate solution caused a villus surface area increase of 38% on d 16 of incubation and 23% on day of hatch relative to controls (P < 0.05). The in ovo injected pigeons exhibited greater (P < 0.05) activities of jejunal sucrase, maltase, and alkaline phosphatase from d 16 of incubation to day of hatch compared with the controls. At day of hatch, aminopeptidase-N activity in embryos injected in ovo was approximately 27% greater (P < 0.05) than control embryos. Enhanced expressions of the jejunal sodium glucose transporter 1, glucose transporter 2, and aminopeptidase-N mRNA were found at d 16 of incubation in embryos that received carbohydrate solution into the amniotic fluid in comparison with the control group (P < 0.05). These results indicate that the in ovo injected pigeon may hatch with more mature enterocytes and greater intestinal digestive and absorptive capacity than the conventional hatchling. Therefore, the in ovo injected pigeons may become more precocial at hatch and easier to hand-rear during the immediate posthatch period.

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.

This study was conducted to evaluate gene expression of the amino acid transporter in post-hatch pigeon small intestine and the association of pigeon milk amino acid with the above transporter's gene expression. A total of 48 pigeon breeding families were randomly allocated to 8 groups of 6 replicates of one parental pigeon pair and 2 squabs. Samples of pigeon milk and duodenum, jejunum, and ileum were collected on d 1, 2, 3, 4, 6, 8, 10, and 14 post hatch. The results showed that levels of crude protein (8.93 to 15.56%) were highest in pigeon milk on an air-dry basis. Amino acid content in pigeon milk remained constant in the first 4 d, declined abruptly at d 6, then increased dramatically from d 8 to 14. There was a significant effect of interaction between age and intestinal segments on those amino acid transporters gene expression. mRNA abundance of ATB0'+, SNAT-2, LAT-4, rBAT, b0'+AT, EAAT-3 and PAT-1 was highest in the ileum; B0AT1, asc-1, and IMINO were predominate in the jejunum; and CAT-1 and y+LAT2 were greatest in the duodenum. Age-related changes of amino acid transporter mRNA was inconsistent. mRNA levels of SNAT-2, rBAT, y+LAT2, b0'+AT, and EAAT-3 ascended with age, whereas that of asc-1, CAT-1, and IMINO diminished significantly. Levels of B0AT1 and PAT-1 mRNA abundance were minimized at d 6. However, few correlations were found between pigeon milk amino acid and the amino acid transporter gene expressions in squab small intestine. Our findings provide a comprehensive elaboration on ontogeny of the amino acid transporter in post-hatch pigeon intestine.

The effects of in ovo feeding of carbohydrates on hatchability, BW, yolk sac weights (YSW), pectoral muscle weights (PMW), liver and pectoral muscle glycogen concentration, serum glucose level, and hepatic glucose-6-phosphatase activity of domestic pigeons, hatched from eggs laid by a 40-wk-old breeder flock, were investigated. At 14.5 of incubation, fertile eggs were injected with 200 μL of 1.5% maltose (M) + 1.5% sucrose (S), 2.5% M + 2.5% S, 3.5% M + 3.5% S, or 4.5% M + 4.5% S in 0.75% saline, with controls not injected. Results showed that in ovo injection with 1.5% M + 1.5% S or 2.5% M + 2.5% S increased the hatchability compared with the control, whereas injection of 4.5% M + 4.5% S decreased the hatchability. The BW at hatch was quadratic, and BW was maximized by injecting 2.5% M + 2.5% S. The YSW at hatch decreased linearly by the injection with 3.5% M + 3.5% S compared with the control group. In ovo injection of 2.5% M + 2.5% S increased the PMW at hatch. There were no significant differences between any of the treatment groups for liver glycogen reserves. Serum glucose level at hatch was quadratic, and the glucose level was maximized between supplemental 2.5% M + 2.5% S and supplemental 3.5% M + 3.5% S. The pectoral muscle glycogen reserves increased quadratically as supplemental carbohydrates increased, and the response was maximized by injecting 2.5% M + 2.5% S. In conclusion, the present results demonstrate that the injected carbohydrates are available for use and storage. In ovo feeding of carbohydrates, especially at the level of 2.5% M + 2.5% S, on 14.5 d of incubation can improve the hatchability, BW, and PMW by elevating the pectoral muscle glycogen reserves in domestic pigeons at hatch. Results also suggested that in ovo injection of carbohydrates could increase the yolk sac nutrient utilization and hence might enhance the pigeon enteric development.