This study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers....This study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per cage.The dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)O.Compared with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(P<0.0001).Adding 640 and 1,280 mg Fe kg^(-1)significantly decreased ADG(P<0.0001)and average daily feed intake(ADFI)(P<0.0001)compared with supplementation of 20mg Fe kg^(-1).Malondialdehyde(MDA)concentration in plasma and duodenum increased linearly(P<0.0001),but MDA concentration in liver and jejunum increased linearly(P<0.05)or quadratically(P<0.05)with increased dietary Fe concentration.The villus height(VH)in duodenum and jejunum,and the ratio of villus height to crypt depth(V/C)in duodenum decreased linearly(P?0.05)as dietary Feincreased.As dietary Fe increased,the jejunal relative mRNA abundance of claudin-1 decreased linearly(P=0.001),but the jejunal relative mRNA abundance of zona occludens-1(ZO-1)and occludin decreased linearly(P?0.05)or quadratically(P?0.05).Compared with the supplementation of 20 mg Fe kg^(-1),the supplementation of640 mg Fe kg^(-1)or higher increased(P?0.05)MDA concentrations in plasma,duodenum,and jejunum,decreased VH in the duodenum and jejunum,and the addition of 1,280 mg Fe kg^(-1)reduced(P?0.05)the jejunal tight junction protein(claudin-1,ZO-1,occludin)mRNA abundance.In summary,640 mg of supplemental Fe kg^(-1)or greater was associated with decreased growth performance,increased oxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein.展开更多
Fatty acid transport protein-1 （FATP-1） is one of the important transporter proteins involved in fatty acid transmembrane transport and fat deposition. To study the relationship between FATP-1 mRNA expression and fa...Fatty acid transport protein-1 （FATP-1） is one of the important transporter proteins involved in fatty acid transmembrane transport and fat deposition. To study the relationship between FATP-1 mRNA expression and fat deposition, chicken （Gallus gallus） FATP-1 sequence was first cloned by rapid amplification of cDNA ends （RACE）. Tissue samples of chest muscle, leg muscle, subcutaneous fat, and abdominal fat were collected from six male and six female broilers each, at 22 days, 29 days, and 42 days, respectively. The tissue specificity and ontogenesis expression pattern of the FATP-1 mRNA of yellow-feathered broilers was studied by real-time reverse transcription polymerase chain reaction （RT-PCR）, and the fat deposition laws in different tissues were also compared. A 2,488 bp cDNA sequence of chicken FATP-1 was cloned by RACE （GenBank accession no. DQ352834）, including 547 bp 3＇ end untranslated region （URT） and 1,941 bp open reading frame （ORF）. Chicken FATP-1 encoded 646 amino acid residues, which shared 83.9% and 83.0% identity with those of human and rat, respectively. The results of quantitative PCR demonstrated a constant FATP-1 mRNA expression level in the chest muscle and subcutaneous fat of both male and female broilers at three stages, whereas the expression level of the FATP-1 mRNA in the leg muscle at 42 days was significantly higher than that at 22 days or 29 days. In the abdominal fat of male broilers, the gene expression significantly increased with age, whereas the female broilers showed a dramatic downregulation of FATP-1 expression in abdominal fat at 42 days. This suggested a typical tissue-and gender-specific expression pattern of chicken FATP-1, mediating the specific process of fatty acid transport or utilization in muscle and adipose tissues.展开更多
Quail egg ovomucoid can inhibit activation of basophils and eosinophils,while hen egg ovomucoid has been shown to be a major allergen,named Gal d 1.At present,the differences in structure and function between two ovom...Quail egg ovomucoid can inhibit activation of basophils and eosinophils,while hen egg ovomucoid has been shown to be a major allergen,named Gal d 1.At present,the differences in structure and function between two ovomucoid are unclear.We found the homology of ovomucoid in quail eggs and hen eggs reached77%.Compared with hen egg ovomucoid,the distribution of secondary structure was different in AA52-53,AA57-58,AA66-68,AA71-72,AA131-133,AA139-140,AA157-159 and AA184-185.Among 9 epitopes of egg ovomucoid,there were different amino acids from quail egg ovomucoid in 8 epitopes.Recombination quail egg ovomucoid had trypsin inhibition activity and quail egg ovomucoid didn't specifically bind to serum of eggs allergic patients.Quail egg ovomucoid can significantly inhibit RBL-2 H3 cells degranulation and protect cells morphology to a certain extent,indicating quail egg ovomucoid can inhibit cells activation and have potential anti-allergic effects,which is related to trypsin inhibitory activity.The difference in sensitization compare to hen egg ovomucoid may be due to amino acids differences affecting protein structure by changing antigenic epitopes.展开更多
The myostatin(MSTN)gene is considered a potential genetic marker to improve economically important traits in live-stock,since the discovery of its function using the MSTN knockout mice.The anti-myogenic function of th...The myostatin(MSTN)gene is considered a potential genetic marker to improve economically important traits in live-stock,since the discovery of its function using the MSTN knockout mice.The anti-myogenic function of the MSTN gene was further demonstrated in farm animal species with natural or induced mutations.In poultry species,myo-genesis in cell culture was regulated by modulation of the MSTN gene.Also,different expression levels of the MSTN gene in poultry models with different muscle mass have been reported,indicating the conserved myogenic function of the MSTN gene between mammalian and avian species.Recent advances of CRISPR/Cas9-mediated genome edit-ing techniques have led to development of genome-edited poultry species targeting the MSTN gene to clearly dem-onstrate its anti-myogenic function and further investigate other potential functions in poultry species.This review summarizes research conducted to understand the function of the MSTN gene in various poultry models from cells to whole organisms.Furthermore,the genome-edited poultry models targeting the MSTN gene are reviewed to inte-grate diverse effects of the MSTN gene on different traits of poultry species.展开更多
A physically-based numerical three-dimensional earthen dam piping failure model is developed for homogeneous and zoned soil dams.This model is an erosion model,coupled with force/moment equilibrium analyses.Orifice fl...A physically-based numerical three-dimensional earthen dam piping failure model is developed for homogeneous and zoned soil dams.This model is an erosion model,coupled with force/moment equilibrium analyses.Orifice flow and two-dimensional(2D)shallow water equations(SWE)are solved to simulate dam break flows at different breaching stages.Erosion rates of different soils with different construction compaction efforts are calculated using corresponding erosion formulae.The dam's real shape,soil properties,and surrounding area are programmed.Large outer 2D-SWE grids are used to control upstream and downstream hydraulic conditions and control the boundary conditions of orifice flow,and inner 2D-SWE flow is used to scour soil and perform force/moment equilibrium analyses.This model is validated using the European Commission IMPACT(Investigation of Extreme Flood Processes and Uncertainty)Test#5 in Norway,Teton Dam failure in Idaho,USA,and Quail Creek Dike failure in Utah,USA.All calculated peak outflows are within 10%errors of observed values.Simulation results show that,for a V-shaped dam like Teton Dam,a piping breach location at the abutment tends to result in a smaller peak breach outflow than the piping breach location at the dam's center;and if Teton Dam had broken from its center for internal erosion,a peak outflow of 117851 m'/s,which is 81%larger than the peak outflow of 65120 m3/s released from its right abutment,would have been released from Teton Dam.A lower piping inlet elevation tends to cause a faster/earlier piping breach than a higher piping inlet elevation.展开更多
Objective To establish abdominal fat accumulation with hyperuricemia and hypercholesterolemia quail model fed with high fat diet. And then to investigate the pathological characteristics of this quail model. Methods ...Objective To establish abdominal fat accumulation with hyperuricemia and hypercholesterolemia quail model fed with high fat diet. And then to investigate the pathological characteristics of this quail model. Methods Thirty Longcheng quails were randomly divided into two groups： control group and model group （n=15）. The control group quails were fed with normal diet and model group quails were fed with high fat diet for 14 days. After a 12-hour overnight fast, liver and abdominal fat at euthanasia as well as serum were collected. The levels of serum uric acid, total cholesterol, high density lipoprotein cholesterol （HDL-C）, low density lipoprotein cholesterol （LDL-C）, triglyceride, free fatty acid （FFA）, and blood glucose were assayed. The activity changes of adenosine deaminase （ADA）, xanthine oxidase （XOD）, lipoprotein lipase （LPL）, hepatic lipase （HL）, and fatty acid synthetase （FAS） were analyzed. Results Compared with control group, the abdominal fat content （0.74±0.63 vs. 1.36±0.65 g, P〈0.05） and abdominal fat index （0.44%±0.30% vs. 0.85%±0.30%, P〈0.01） as well as live lipid index （3.61%±0.65% vs. 11.33%±2.14%, P〈0.01） in model group significantly increased; the levels of serum uric acid （210.61±94,76 vs. 304.25±141.94 /amol/L, P〈0.05）, total cholesterol （4.20±0.51 vs. 20.10±11.25 mmol/L, P〈0.01）, LDL-C （1.16±0.29 vs. 10.78±6.48 mmol/L, P〈0.01）, and FFA （0.39±0.14 vs. 0.55±0.15 mmol/L, P〈0.01） in model group significantly increased; HDL-C （5.85±0.95 vs. 4.14±2.03 mmol/L, P〈0.05） significantly decreased; the levels of triglyceride and blood glucose had no significant changes （P〉0.05）; the activities of ADA （9.71±3.05 vs. 17.19±5.10 U/ml, P〈0.01） and XOD （10.58±6,88 vs. 19.22＋9.44 U/L, P〈0.01） in model group significantly increased; and FAS, LPL, HL had no significant changes （P〉0.05）. Conclusions High fat diet can induce abdominal fat accumulation with hyperuricemia and hypercholesterolemia quail model. The changes of uric acid and lipid metabolic enzyme activities may he the pathological mechanism of abdominal fat accumulation with hyperuricemia and hypercholesterolemia.展开更多
[ Objective] To investigate the effects of Newcastle disease vaccination and lead exposure on growth and development of egg yellow feather quail. [ Method] Ninety 14-day-old quails were assigned randomly to 10 groups ...[ Objective] To investigate the effects of Newcastle disease vaccination and lead exposure on growth and development of egg yellow feather quail. [ Method] Ninety 14-day-old quails were assigned randomly to 10 groups （ n = 9）, and they fed and drunk at liberty. A 2 ×5 factorial design was used. The quail immunized with ND vaccine and those non-immunized were exposed to lead at a dosage of 0, 50,500, 1 000 and 2 000 mg/L, respectively. [Result] The ND immunization reduced body weight significantly （ P 〈 0.01 ） and increased liver index and serum levels of hy- aluronic acid in quail within 1 -2 weeks post inoculation. The quail exposed to 2 000 mg/L lead acetate had significantly lower body weight than the control （ P 〈 0.01 ）. From 7 weeks old, the same inhibitory effect was observed in the quail＇exposed to lead at different dosages （ P 〈 0.01 ）. In addition, the lead poisoning could cause decreased feed intake, depilation, gonadal dysgenesis, and increased serum levels of hyaluronic acid. [ Conduslon] The inhibitory effect of ND vaccination on growth of quail occurs within 1 -2 weeks post inoculation; thus, the effects of immune stress should not be worried in quail production. The lead poisoning has significant effects on body weight and feed intake of quail, and lead dosage and duration affect the inhibitory effects of lead. Gonadal dysgenesis is an important indicator of lead poisoning in. quail. The serum levels of hyaluronic acid can be used to determine whether the quail have been immunized with ND vaccine or have contacted lead pollutants.展开更多
In this study, a protocol was developed to identify the sex of earlier embryos of chicken （♂）-quail （♀） hybrids and successfully tested the sex proportion of each period （66-120 h）. We acquired cross bred eggs...In this study, a protocol was developed to identify the sex of earlier embryos of chicken （♂）-quail （♀） hybrids and successfully tested the sex proportion of each period （66-120 h）. We acquired cross bred eggs by artificial insemination, hatched them in the same batch according to the standard hatching condition of chicken, and collected earlier living embryos at 66, 72, 78, 84, 90, 96, 102, 108, 114, and 120 h randomly. We adopted RT-PCR protocol and multiple PCR, made the known sex quail as the external control, employed fl-actin as the internal control, and used primers that were designed according to conservative area of gene Wpkci of quail to identify the sex of earlier hybrid embryos. The results indicated that the primer of Wpkci can be used to identify the sex of hybrid embryos accurately; there were more male than female in earlier embryos, the sex proportion of earlier embryos compared with academic numerical value was significantly different （P〈0.01）, and there was no difference between different periods （P〉0.05）. In the present study, we concluded that a simple, fast, credible and stable protocol to identify the sex of earlier hybrids embryos had been established by using primer of Wpkci; in earlier embryos, the death rate of female was higher than that of male and there was no fluctuant peak.展开更多
基金supported by the National Natural Science Foundation of China(31501977)the Sichuan Provincial Key R&D Project China(22ZDYF0194)the Double World-Class Project of Southwest Minzu University China(XM2023010)。
文摘This study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per cage.The dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)O.Compared with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(P<0.0001).Adding 640 and 1,280 mg Fe kg^(-1)significantly decreased ADG(P<0.0001)and average daily feed intake(ADFI)(P<0.0001)compared with supplementation of 20mg Fe kg^(-1).Malondialdehyde(MDA)concentration in plasma and duodenum increased linearly(P<0.0001),but MDA concentration in liver and jejunum increased linearly(P<0.05)or quadratically(P<0.05)with increased dietary Fe concentration.The villus height(VH)in duodenum and jejunum,and the ratio of villus height to crypt depth(V/C)in duodenum decreased linearly(P?0.05)as dietary Feincreased.As dietary Fe increased,the jejunal relative mRNA abundance of claudin-1 decreased linearly(P=0.001),but the jejunal relative mRNA abundance of zona occludens-1(ZO-1)and occludin decreased linearly(P?0.05)or quadratically(P?0.05).Compared with the supplementation of 20 mg Fe kg^(-1),the supplementation of640 mg Fe kg^(-1)or higher increased(P?0.05)MDA concentrations in plasma,duodenum,and jejunum,decreased VH in the duodenum and jejunum,and the addition of 1,280 mg Fe kg^(-1)reduced(P?0.05)the jejunal tight junction protein(claudin-1,ZO-1,occludin)mRNA abundance.In summary,640 mg of supplemental Fe kg^(-1)or greater was associated with decreased growth performance,increased oxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein.
基金supported by the National Basic Research Program of China(973 Program)(No.2004CB117501)the National Natural Sciences Foundation of China(No.30500367)+1 种基金Guangdong Provincial Natural Science Foundation for Program of Research Team(No.04205804)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China.
文摘Fatty acid transport protein-1 （FATP-1） is one of the important transporter proteins involved in fatty acid transmembrane transport and fat deposition. To study the relationship between FATP-1 mRNA expression and fat deposition, chicken （Gallus gallus） FATP-1 sequence was first cloned by rapid amplification of cDNA ends （RACE）. Tissue samples of chest muscle, leg muscle, subcutaneous fat, and abdominal fat were collected from six male and six female broilers each, at 22 days, 29 days, and 42 days, respectively. The tissue specificity and ontogenesis expression pattern of the FATP-1 mRNA of yellow-feathered broilers was studied by real-time reverse transcription polymerase chain reaction （RT-PCR）, and the fat deposition laws in different tissues were also compared. A 2,488 bp cDNA sequence of chicken FATP-1 was cloned by RACE （GenBank accession no. DQ352834）, including 547 bp 3＇ end untranslated region （URT） and 1,941 bp open reading frame （ORF）. Chicken FATP-1 encoded 646 amino acid residues, which shared 83.9% and 83.0% identity with those of human and rat, respectively. The results of quantitative PCR demonstrated a constant FATP-1 mRNA expression level in the chest muscle and subcutaneous fat of both male and female broilers at three stages, whereas the expression level of the FATP-1 mRNA in the leg muscle at 42 days was significantly higher than that at 22 days or 29 days. In the abdominal fat of male broilers, the gene expression significantly increased with age, whereas the female broilers showed a dramatic downregulation of FATP-1 expression in abdominal fat at 42 days. This suggested a typical tissue-and gender-specific expression pattern of chicken FATP-1, mediating the specific process of fatty acid transport or utilization in muscle and adipose tissues.
基金supported by the Beijing Municipal Natural Science Foundation of China(7202100)。
文摘Quail egg ovomucoid can inhibit activation of basophils and eosinophils,while hen egg ovomucoid has been shown to be a major allergen,named Gal d 1.At present,the differences in structure and function between two ovomucoid are unclear.We found the homology of ovomucoid in quail eggs and hen eggs reached77%.Compared with hen egg ovomucoid,the distribution of secondary structure was different in AA52-53,AA57-58,AA66-68,AA71-72,AA131-133,AA139-140,AA157-159 and AA184-185.Among 9 epitopes of egg ovomucoid,there were different amino acids from quail egg ovomucoid in 8 epitopes.Recombination quail egg ovomucoid had trypsin inhibition activity and quail egg ovomucoid didn't specifically bind to serum of eggs allergic patients.Quail egg ovomucoid can significantly inhibit RBL-2 H3 cells degranulation and protect cells morphology to a certain extent,indicating quail egg ovomucoid can inhibit cells activation and have potential anti-allergic effects,which is related to trypsin inhibitory activity.The difference in sensitization compare to hen egg ovomucoid may be due to amino acids differences affecting protein structure by changing antigenic epitopes.
基金funded by the United States Department of Agricul-ture National Institute of Food and Agriculture Grant(Project No.2020-67030-31338)。
文摘The myostatin(MSTN)gene is considered a potential genetic marker to improve economically important traits in live-stock,since the discovery of its function using the MSTN knockout mice.The anti-myogenic function of the MSTN gene was further demonstrated in farm animal species with natural or induced mutations.In poultry species,myo-genesis in cell culture was regulated by modulation of the MSTN gene.Also,different expression levels of the MSTN gene in poultry models with different muscle mass have been reported,indicating the conserved myogenic function of the MSTN gene between mammalian and avian species.Recent advances of CRISPR/Cas9-mediated genome edit-ing techniques have led to development of genome-edited poultry species targeting the MSTN gene to clearly dem-onstrate its anti-myogenic function and further investigate other potential functions in poultry species.This review summarizes research conducted to understand the function of the MSTN gene in various poultry models from cells to whole organisms.Furthermore,the genome-edited poultry models targeting the MSTN gene are reviewed to inte-grate diverse effects of the MSTN gene on different traits of poultry species.
文摘A physically-based numerical three-dimensional earthen dam piping failure model is developed for homogeneous and zoned soil dams.This model is an erosion model,coupled with force/moment equilibrium analyses.Orifice flow and two-dimensional(2D)shallow water equations(SWE)are solved to simulate dam break flows at different breaching stages.Erosion rates of different soils with different construction compaction efforts are calculated using corresponding erosion formulae.The dam's real shape,soil properties,and surrounding area are programmed.Large outer 2D-SWE grids are used to control upstream and downstream hydraulic conditions and control the boundary conditions of orifice flow,and inner 2D-SWE flow is used to scour soil and perform force/moment equilibrium analyses.This model is validated using the European Commission IMPACT(Investigation of Extreme Flood Processes and Uncertainty)Test#5 in Norway,Teton Dam failure in Idaho,USA,and Quail Creek Dike failure in Utah,USA.All calculated peak outflows are within 10%errors of observed values.Simulation results show that,for a V-shaped dam like Teton Dam,a piping breach location at the abutment tends to result in a smaller peak breach outflow than the piping breach location at the dam's center;and if Teton Dam had broken from its center for internal erosion,a peak outflow of 117851 m'/s,which is 81%larger than the peak outflow of 65120 m3/s released from its right abutment,would have been released from Teton Dam.A lower piping inlet elevation tends to cause a faster/earlier piping breach than a higher piping inlet elevation.
基金Supported by National Nature Science Foundation of China (30472282)Beijing Natural Science Foundation (7052036)Major State Basic Research Development Program of China (973 Program, 2007CB512605)
文摘Objective To establish abdominal fat accumulation with hyperuricemia and hypercholesterolemia quail model fed with high fat diet. And then to investigate the pathological characteristics of this quail model. Methods Thirty Longcheng quails were randomly divided into two groups： control group and model group （n=15）. The control group quails were fed with normal diet and model group quails were fed with high fat diet for 14 days. After a 12-hour overnight fast, liver and abdominal fat at euthanasia as well as serum were collected. The levels of serum uric acid, total cholesterol, high density lipoprotein cholesterol （HDL-C）, low density lipoprotein cholesterol （LDL-C）, triglyceride, free fatty acid （FFA）, and blood glucose were assayed. The activity changes of adenosine deaminase （ADA）, xanthine oxidase （XOD）, lipoprotein lipase （LPL）, hepatic lipase （HL）, and fatty acid synthetase （FAS） were analyzed. Results Compared with control group, the abdominal fat content （0.74±0.63 vs. 1.36±0.65 g, P〈0.05） and abdominal fat index （0.44%±0.30% vs. 0.85%±0.30%, P〈0.01） as well as live lipid index （3.61%±0.65% vs. 11.33%±2.14%, P〈0.01） in model group significantly increased; the levels of serum uric acid （210.61±94,76 vs. 304.25±141.94 /amol/L, P〈0.05）, total cholesterol （4.20±0.51 vs. 20.10±11.25 mmol/L, P〈0.01）, LDL-C （1.16±0.29 vs. 10.78±6.48 mmol/L, P〈0.01）, and FFA （0.39±0.14 vs. 0.55±0.15 mmol/L, P〈0.01） in model group significantly increased; HDL-C （5.85±0.95 vs. 4.14±2.03 mmol/L, P〈0.05） significantly decreased; the levels of triglyceride and blood glucose had no significant changes （P〉0.05）; the activities of ADA （9.71±3.05 vs. 17.19±5.10 U/ml, P〈0.01） and XOD （10.58±6,88 vs. 19.22＋9.44 U/L, P〈0.01） in model group significantly increased; and FAS, LPL, HL had no significant changes （P〉0.05）. Conclusions High fat diet can induce abdominal fat accumulation with hyperuricemia and hypercholesterolemia quail model. The changes of uric acid and lipid metabolic enzyme activities may he the pathological mechanism of abdominal fat accumulation with hyperuricemia and hypercholesterolemia.
基金funded by the Key Scientific and Technological Project of Henan Province ( 082102130002)
文摘[ Objective] To investigate the effects of Newcastle disease vaccination and lead exposure on growth and development of egg yellow feather quail. [ Method] Ninety 14-day-old quails were assigned randomly to 10 groups （ n = 9）, and they fed and drunk at liberty. A 2 ×5 factorial design was used. The quail immunized with ND vaccine and those non-immunized were exposed to lead at a dosage of 0, 50,500, 1 000 and 2 000 mg/L, respectively. [Result] The ND immunization reduced body weight significantly （ P 〈 0.01 ） and increased liver index and serum levels of hy- aluronic acid in quail within 1 -2 weeks post inoculation. The quail exposed to 2 000 mg/L lead acetate had significantly lower body weight than the control （ P 〈 0.01 ）. From 7 weeks old, the same inhibitory effect was observed in the quail＇exposed to lead at different dosages （ P 〈 0.01 ）. In addition, the lead poisoning could cause decreased feed intake, depilation, gonadal dysgenesis, and increased serum levels of hyaluronic acid. [ Conduslon] The inhibitory effect of ND vaccination on growth of quail occurs within 1 -2 weeks post inoculation; thus, the effects of immune stress should not be worried in quail production. The lead poisoning has significant effects on body weight and feed intake of quail, and lead dosage and duration affect the inhibitory effects of lead. Gonadal dysgenesis is an important indicator of lead poisoning in. quail. The serum levels of hyaluronic acid can be used to determine whether the quail have been immunized with ND vaccine or have contacted lead pollutants.
文摘In this study, a protocol was developed to identify the sex of earlier embryos of chicken （♂）-quail （♀） hybrids and successfully tested the sex proportion of each period （66-120 h）. We acquired cross bred eggs by artificial insemination, hatched them in the same batch according to the standard hatching condition of chicken, and collected earlier living embryos at 66, 72, 78, 84, 90, 96, 102, 108, 114, and 120 h randomly. We adopted RT-PCR protocol and multiple PCR, made the known sex quail as the external control, employed fl-actin as the internal control, and used primers that were designed according to conservative area of gene Wpkci of quail to identify the sex of earlier hybrid embryos. The results indicated that the primer of Wpkci can be used to identify the sex of hybrid embryos accurately; there were more male than female in earlier embryos, the sex proportion of earlier embryos compared with academic numerical value was significantly different （P〈0.01）, and there was no difference between different periods （P〉0.05）. In the present study, we concluded that a simple, fast, credible and stable protocol to identify the sex of earlier hybrids embryos had been established by using primer of Wpkci; in earlier embryos, the death rate of female was higher than that of male and there was no fluctuant peak.
