首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 468 毫秒
1.
2.
  1. A trial was conducted to explore the effect of feeding graded concentrations of green tea extract (GTE; 125, 250, 500, 1000 and 2000 mg/kg) on the growth performance, serum lipid profile, liver glutathione-reduced, thigh muscle malondialdehyde and humoral immune response against Newcastle disease virus vaccines of broiler chickens from hatching to 42 d of age. The results of broilers fed on GTE were contrasted to those fed on butylated hydroxytoluene (BHT; 125 mg/kg) or unsupplemented controls.

  2. The obtained results revealed no significant difference among treatments in the measured growth performance parameters (body weight, average daily gain, average daily feed intake and feed conversion ratio), per cent liveability and serum lipid profile (total lipid, total cholesterol, high-density, low-density and very low-density lipoprotein cholesterols).

  3. Dietary intake of GTE resulted in a significant increase in the liver glutathione-reduced level compared to the control. The glutathione-reduced level of broilers fed on the BHT diet was not significantly different from that of broilers fed on GTE or control diets. Feeding GTE or BHT resulted in a significant decrease in the malondialdehyde level of meat tissue.

  4. The specific antibody titre against Newcastle disease virus vaccines was significantly increased at 28 and 35 d of age in broilers fed on diets supplemented with GTE but not with BHT.

  5. In conclusion, GTE was found to possess antioxidant and immunostimulant characteristics for broilers when supplemented to their diets, and its optimum inclusion level ranged from 125 to 500 mg/kg.

  相似文献   

3.
  1. The fat mass and obesity associated (FTO) gene, which encodes a demethylase of m6A, has been reported to respond to lipopolysaccharide (LPS) and to serve as a link between inflammation and metabolic responses. The objective of this study was to determine whether LPS-induced changes in the expression of FTO and metabolic genes are associated with alterations of m6A in relevant mRNAs.

  2. LPS challenge significantly decreased hepatic mRNA expression of carnitine palmitoyl transferase 1 (CPT1) and CPT2, which coincided with a tendency of higher triglyceride accumulation in the liver.

  3. LPS significantly down-regulated the full length cFTO1, yet up-regulated the truncated cFTO4 protein in the liver nuclear extracts.

  4. Nuclear protein content of cFTO4 in the liver was negatively correlated with the mRNA abundances of CPT1 (r = 0.629) and CPT2 (r = 0.622).

  5. Methylated RNA immunoprecipitation analysis revealed that the m6A level around the translation start site of CPT1 was markably decreased in the liver of LPS-treated chickens.

  6. These results indicate that LPS-induced changes in FTO protein expression are associated with alteration of mRNA m6A modification in chicken liver.

  相似文献   

4.
  1. The post-mortem proteolysis and tenderisation between male and female duck breast muscles were compared.

  2. The results showed that μ-calpain activity, desmin content and shear force decreased more quickly in female than in male samples stored at 5°C.

  3. It is suggested that the post-mortem proteolysis and tenderisation are more rapid and extensive in female duck breast muscle.

  相似文献   

5.
  1. The aim of this study was to construct lentivirus-mediated short hairpin RNA (shRNA) vectors targeting the duck MSTN gene and investigate whether these vectors can affect the development of duck primary cultured embryonic myoblasts.

  2. MSTN mRNA levels in the myoblasts were detected using quantitative real-time polymerase chain reaction (PCR), cell proliferation was assessed by MTT assays and cell differentiation was assayed by photography.

  3. MSTN mRNA levels in PLL3.7-MSTN-shRNA1, PLL3.7-MSTN-shRNA2 and PLL3.7-MSTN-shRNA3 lentivirus-mediated shRNA groups were reduced by 61.6%, 76.9% and 79.1%, respectively, compared to control cells.

  4. Down-regulation of MSTN in duck embryonic myoblasts stimulated cell proliferation and inhibited differentiation, accompanied by a greater than twofold down-regulation of MyoD expression and up-regulation of Myf5 expression.

  5. These results revealed that silencing of MSTN changes the development of duck embryonic myoblasts by regulating the expression level of MyoD and Myf5 genes.

  相似文献   

6.
  1. Agouti signalling protein (ASIP) is an endogenous antagonist of melanocortin-1 receptor (MC1R) and is involved in the regulation of pigmentation in mammals. The objective of this study was to identify and characterise the ASIP gene in domestic goose.

  2. The goose ASIP cDNA consisted of a 44-nucleotide 5?-terminal untranslated region (UTR), a 390-nucleotide open-reading frame (ORF) and a 45-nucleotide 3?-UTR. The length of goose ASIP genomic DNA was 6176 bp, including three coding exons and two introns.

  3. Bioinformatic analysis indicated that the ORF encodes a protein of 130 amino-acid residues with a molecular weight of 14.88 kDa and an isoelectric point of 9.73.

  4. Multiple sequence alignments and phylogenetic analysis showed that the amino-acid sequence of ASIP was conserved in vertebrates, especially in the avian species.

  5. RT-qPCR showed that the goose ASIP mRNA was differentially expressed in the pigment deposition tissues, including eye, foot, feather follicle, skin of the back, as well as in skin of the abdomen. The expression level of the ASIP gene in skin of the abdomen was higher than that in skin of the back.

  6. Those findings will contribute to further understanding the functions of the ASIP gene in geese plumage colouring.

  相似文献   

7.
  1. The types and methods of use of antibiotics in poultry farms in Cameroon, residual levels and potential microbial resistance were determined.

  2. A questionnaire-based survey identified the different antibiotics used and high-performance liquid chromatography (HPLC) was used to determine residual levels of antibiotics.

  3. Pathogens were isolated, identified by use of commercial API kits and minimum inhibition concentration (MIC) was determined.

  4. Oxytetracyclin, tylocip and TCN (oxytetracycline, chloramphenicol and neomycin) were the most frequently used antibiotics. Antibiotics screened by HPLC were chloramphenicol, tetracycline and vancomycin. All of them except vancomycin were detected, and the concentration of these antibiotics was higher than the maximum residual limits (MRL) set by regulatory authorities.

  5. No residues of various antibiotics were found in egg albumen or yolk. The concentration of tetracycline was significantly higher in liver (150 ± 30 µg/g) than in other tissues.

  6. Foodborne pathogens, including Salmonella spp., Staphylococcus spp., Listeria spp., Clostridium spp. and Escherichia spp., were identified. Most of the pathogens were resistant to these various antibiotics tested.

  7. These findings imply the need for better management of antibiotic use to control sources of food contamination and reduce health risks associated with the presence of residues and the development of resistant pathogens by further legislation and enforcement of regulations on food hygiene and use of antibiotics.

  相似文献   

8.
  1. An experiment was conducted to study the effects of dietary supplementation of water-soluble ionised or chelated mineral mixture on growth performance, nutrient digestibility, blood characteristics, relative organ weight, meat quality and excreta microflora in broilers.

  2. A total of 408 Arbor Acres broilers (17 birds in 8 replicate pens) were randomly allocated into one of the following three treatments: (1) Control/basal diet (CON), (2) T1 (basal diet + 0.5% ionised mineral mixture solution, pH 3.0) and (3) T2 (basal diet + 0.5% chelated mineral mixture solution, pH 3.0).

  3. The body weight gain was greater and feed conversion ratio was lower in broilers supplemented with ionised or chelated mineral liquid complex compared to CON during the grower and overall phase of the experiment.

  4. No significant effect in the concentration of Ca and P in the blood was observed in birds supplemented with ionised or chelated mineral mixture solution. No adverse effects were observed in organ weight and meat quality with ionised or chelated mineral mixture supplementation.

  5. Regarding intestinal microbiota counts there was a reduction of Escherichia coli counts in the small intestine in ionised mineral supplemented birds. In the large intestine, E. coli as well as Salmonella populations were reduced in ionised mineral supplemented birds.

  6. In conclusion, ionised or chelated minerals have partial positive effects in improving growth performance and reducing pathogenic bacteria load in the gastro-intestinal tract.

  相似文献   

9.
  1. Blood samples from 1-, 5- and 10-year-old broad-breasted white turkeys were used to determine haematological and serum values. There were 8 turkeys in each age group.

  2. Mean haematocrit, haemoglobin and creatinine values were higher in the 1-year-old than in 10-year-old turkeys.

  3. Mean alanine aminotransferase was greater in 1 year old than in 10 year olds and greater in 5 year olds than in 10 year olds. Aspartate aminotransferase values were significantly different between all age groups.

  4. Mean alkaline phosphatase was less in 1-year-old than in 10-year-old turkeys. There were no significant differences between the three groups for cholesterol, glucose, total protein, albumin, globulin, calcium and bilirubin.

  5. All male turkeys had higher haemoglobin and haematocrit values than age-matched females.

  6. These data will help establish basic background references values in geriatric turkeys used in research.

  相似文献   

10.
  1. The aim of this study was to assess mRNA abundance of calpain 1 (CAPN1) and calpain 3 (CAPN3) in breast muscle of 80 fast-growing (FG) and slow-growing broilers (SG) and relate gene expression in relation to growth and Warner Bratzler (WB) shear force of breast muscle.

  2. The expression of CAPN1 and CAPN3 genes was higher in the FG compared to the SG line, but significant results were obtained only for CAPN1. The CAPN1 mRNA level was strongly dependent on line and gender interaction.

  3. Lower values of shear force were observed in the FG line, where a higher level of calpain expression was shown.

  4. A new panel of housekeeping genes (RPL4 and SDHA) for normalisation of gene expression in muscle tissues could be used in other studies of gene expression in chicken.

  相似文献   

11.
  1. A DiagNose II electronic nose (e-nose) system was tested to evaluate the performance of such systems in the detection of the Salmonella enterica pathogen in poultry manure.

  2. To build a database, poultry manure samples were collected from 7 broiler houses, samples were homogenised, and subdivided into 4 portions. One portion was left as is; the other three portions were artificially infected with S. enterica.

  3. An artificial neural network (ANN) model was developed and validated using the developed database.

  4. In order to test the performance of DiagNose II and the ANN model, 16 manure samples were collected from 6 different broiler houses and tested using these two systems.

  5. The results showed that DiagNose II was able to classify manure samples correctly as infected or non-infected based on the ANN model developed with a 94% level of accuracy.

  相似文献   

12.
  1. The objective of this study was to identify any issues arising during the laboratory testing of samples collected under the National Control Programme for Salmonella.

  2. A questionnaire-based survey was conducted among Defra (Department for Environment, Food and Rural Affairs)-approved testing laboratories in order to identify any complicating factors that the laboratories may encounter during the processing of samples.

  3. Samples were reported to arrive in good condition and within the specified time frame after collection. The only concern was that new clients may be unaware of the procedure or correct sampling consumables to use.

  4. There was evidence of variability between laboratories regarding the sample testing procedure used, with deviation from the guidelines in some cases.

  5. This finding suggests that further guidance for laboratories on methodology is likely to be beneficial as this could help improve the detection of low levels of Salmonella.

  相似文献   

13.
  1. The objective of this study was to estimate growth parameters of carcass components (wing, thighs and drumsticks, back and breast) and organs (heart, liver, gizzard and gut) in males and females of one meat-type quail strain (Coturnix coturnix coturnix) and two laying strains (Coturnix coturnix japonica) designated either yellow or red.

  2. A total of 1350 quail from 1 to 42 d old were distributed in a completely randomised design, with 5 replicates of each strain. The carcass component weights and body organs were analysed weekly and evaluated using the Gompertz function; growth rates were evaluated through derivative equations.

  3. The meat-type strain presented the highest growth rates in carcass components and organs. Across strains, females showed the highest weight of internal organs at maturity compared to males.

  4. Females had greater growth potential in breast, wings and back than males for both yellow and red laying quail.

  相似文献   

14.
  1. Pediococcus spp. were isolated from poultry rectum, faeces and food as good probiotic candidates in order to select strains to be used as probiotic in poultry feed.

  2. A total of 168 lactic acid bacteria were isolated and 51 isolates including 31 Lactobacillus spp. and 20 Pediococcus spp. were able to survive in low pH and bile salt concentration. The Pediococcus spp. were identified and their ability to form biofilm, adhesion to Caco-2 cells and antimicrobial activities against enteric pathogenic bacteria were determined.

  3. The results showed the presence of two strains, Pediococcus acidilactici P17 and P19 in rectal swab samples from 21-d old chickens with significant antibacterial activities against Salmonella enteritidis and Escherichia coli.

  4. The results suggest that only a few isolates of Pediococcus with potential probiotic activities are present in the poultry industry.

  相似文献   

15.
  1. The onset and progression of Salmonella infections was investigated in commercial turkey flocks from placement at 1 d old until slaughter in “brood and move” systems using a longitudinal observational approach based on faeces and environmental sampling with subsequent culture of Salmonella.

  2. Persistent Salmonella Newport contamination was found within rearing houses and on their external concrete aprons after cleaning and disinfection between crops of heavily shedding young birds.

  3. Salmonella shedding was often detected by 5 d of age and the frequency of positive samples peaked at 14–35 d. Thereafter Salmonella isolations declined, especially in the later (fattening) stages. Samples were still Salmonella-positive at low prevalence in half of the intensively sampled houses at slaughter age.

  4. A number of management interventions to combat Salmonella infection of flocks, including sourcing policy, competitive exclusion cultures and cleaning and disinfection, were inadequate to prevent flock infection, although improved disinfection on one unit was associated with a delay in the onset of flock infection.

  相似文献   

16.
  1. This study evaluated the effect of oral administration of colloidal gold nanoparticles on accumulation of gold in the small intestine and intestinal absorption of iron, calcium and potassium under in vitro conditions.

  2. The gold nanoparticles are non-ionic, nanocrystalline, chemically pure particles 5 nm in size, produced in a physical process.

  3. In total, 126 one day-old Ross 308 chicks were assigned to 7 experimental groups of 18 birds each (3 replications of 6 individuals each).

  4. The control group (G-C) did not receive gold nanoparticles. Groups: Au-5(7), Au-10(7) and Au-15(7) received gold nanoparticles in their drinking water in the amounts of 5 mg l?1 for group Au-5(7), 10 mg l?1 for group Au-10(7) and 15 mg l?1 for group Au-15(7) in 8–14, 22–28 and 36–42 d of life. The birds in groups Au-5(3), Au-10(3) and Au-15(3) received gold nanoparticles in the same amounts, but only in 8–10, 22–24 and 36–38 d of life.

  5. The study revealed that nanogold supplied via ingestion leads to dose- and time-dependent accumulation of gold in the intestinal walls.

  6. Nanogold present in the jejunum has a negative impact on the absorption of calcium, iron and potassium under in vitro conditions.

  相似文献   

17.
  1. The experiment was conducted to study whether insulin receptor substance 1 (IRS1) / Protein kinase B (Akt)/target of the rapamycin (TOR) signalling pathway activation stimulates crop milk protein synthesis in the domestic pigeon (Columba livia).

  2. Crop milk was collected from ten 1-d-old squabs and analysed for nutrient content. During the non-breeding period and the first day of lactation, blood samples were collected from 5 pairs of breeding pigeons and the levels of prolactin and insulin were determined.

  3. Crop samples were collected from 5 pairs of breeders at d 14 and 16 of the incubation period and d 1, 3 and 7 of the lactation period. Crop samples were evaluated for changes in crop weight and thickness and changes in the expression patterns of IRS1/Akt/TOR signalling pathway–related proteins.

  4. The results demonstrated that prolactin induces a gradual increase in the relative weight and thickness of the crop, with crops reaching a maximum size at the third day of lactation.

  5. Pigeon crop milk contains 64.1% crude protein and 29.7% crude fat based on dry weight.

  6. Serum prolactin and insulin levels in the lactation period were significantly higher than those in the non-breeding period. Compared with non-breeding pigeons, the expression of the phosphorylated IRS1 phosphorylated Akt, phosphorylated TOR, phosphorylated ribosomal protein S6 kinase, phosphorylated S6, phosphorylated eukaryotic initiation factor 4E binding protein 1 and eukaryotic initiation factor 4E were significantly up-regulated in the crop of pigeons in the lactation period.

  7. In conclusion, prolactin might induce changes in crop tissue and form the physiological structure for crop milk synthesis. Furthermore, the synthesis of crop milk protein is regulated by activation of the IRS1/Akt/TOR signalling pathway.

  相似文献   

18.
Extract

A Mastitis control programme is essentially a biological regulatory system involving the three essential components of any control mechanism:
  • A signal from a detector indicating departure from normality

  • The interpretation of the signal (diagnosis)

  • A feed-back signal to the origin of the detection signal indicating corrective action.

  相似文献   

19.
  1. This study was designed to evaluate the effects of two different complex probiotic supplementations on the growth performance, meat quality, excreta microflora, nutrient retention, blood metabolic profile and noxious gas emissions in broilers.

  2. A total of 612 conventional healthy 1-d-old Ross 308 broilers with body weight of 41 ± 0.3 g were randomly divided into 3 treatments with 12 replicate cages, with 17 broilers in each cage and fed with the following diets: CON-Basal diet, T1-CON + Probiotic A, T2-CON + Probiotic B.

  3. Significant results were observed on body weight gain, but not on feed conversation ratio and feed intake, in the whole experimental period. Increased faecal lactobacillus counts were found with probiotics supplementation. However, no significant effects were found for meat quality, nutrient retention, blood metabolic profile or noxious gas emissions.

  4. In conclusion, both multi-strain probiotics had beneficial effects on growth performance, drip loss percentage and faecal Lactobacillus counts in broilers.

  相似文献   

20.
The tensile strength of egg‐shell material is believed to play an important role in determining whether or not a shell will crack when exposed to an environmental insult. Experiments are described in which shell tensile strength was measured. It is concluded that:
  1. the force required to produce tensile failure did not vary linearly with the width of the piece of shell under test, but with its two‐thirds power;

  2. it varied linearly with the thickness of the shell;

  3. the line relating force at tensile failure to shell thickness did not pass through the origin but intercepted the thickness axis at between about 90 and 130 μm, indicating that the inner layers of a shell, up to about a third of its thickness, contributed little or nothing to its tensile strength;

  4. the slope of the line did not vary with hen or strain of hen, indicating that the shells did not differ in the tensile strength of the material constituting their outer layers (i.e. about the outer two‐thirds);

  5. there were differences between hens and strains in the magnitude of the intercept: shells of the same thickness but from different hens or strains differed in force at tensile failure;

  6. the existence of between‐strain differences in intercept constitutes prima facie evidence that the variation in this trait is under genetic control;

  7. there was a fairly large within‐egg residual component of the variance of force at tensile failure; it represents real variation in tensile strength between apparently similar pieces of the same shell and is believed to be an effect of chance in the distribution of flaws in the shell material;

  8. for any one hen the intercept is the same as that found when shearing strength is measured, so shearing strength (which can be determined easily, quickly and precisely) can be used as a predictor of tensile strength.

Implications for poultry breeders are discussed; it is suggested that they should select for shell strength instead of shell thickness, measuring strength as shearing strength.  相似文献   


设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号