1. The objective of this study was to investigate the association of using a multi-tier aviary system and access to range on flock uniformity in free-range laying hens, and to determine whether the extent of range use or flock uniformity can be predicted from the use of different levels of the aviary system.
2. A total of 13,716 Lohmann Brown hens from five commercial free-range flocks housed in identical houses on the same farm were individually weighed at 16 weeks of age and allocated to five replicate areas within each house. Hen movement in the multi-tier aviary system and on the range was individually monitored using radio frequency identification (RFID). All hens had access to the range from 18 to 22 weeks of age and were exposed to the same management conditions.
3. Whilst only one flock significantly changed its flock uniformity with time, they differed from each other in uniformity and body weight (P = 0.001).
4. Hens spent most of their available time on the lower aviary tier (7.29 ± 0.029 h/hen/day) and on the upper aviary tier (4.29 ± 0.024 h/hen/day) while the least amount of time was spent on the range and in the nest boxes (0.93 ± 0.005 h/hen/day and 1.48 ± 0.007 h, respectively, P = 0.001).
5. Range use was negatively correlated (r = ?0.30) to the time spent on the upper aviary tier and positively correlated (r = 0.46) to the time spent on the lower aviary tier (P = 0.001). Bivariate analysis revealed that range and upper aviary resp. lower aviary tier usage had a significant curvilinear association.
6. In conclusion, the study showed that range use was associated to the time hens spent on the different tiers of the aviary system. Flock uniformity varied between flocks but was not associated with either range and aviary system usage.
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1.The objective of the experiment was to analyse serum profiles of goslings with visceral gout and compare them with those of healthy individuals to identify differentially-abundant metabolites as potential biomarkers.
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2.Untargeted gas chromatography and time-of-flight mass spectrometry (GC-TOF-MS) metabolomic pro?ling was used to compare the serum metabolome of 15 goslings (Anser cygnoides) with gout and 15 healthy goslings (control).
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3.Goslings with gout had a metabolic pro?le distinct from that of the controls, with 45 metabolite levels differing significantly (VIP > 1; P < 0.05) between both groups. Nine metabolites (hydrocortisone, glucose, trans-4-hydroxy-L-proline, galactose, 2-deoxy-D-galactose, beta-mannosylglycerate, d-glucoheptose, zymosterol, and hypoxanthine) were selected through receiver operating characteristics (ROC) analysis (area under curve (AUC) score ≥0.85) as potential biomarkers. Pathway analysis revealed that metabolites with differing levels were mainly involved in galactose, arginine and proline and purine metabolisms.
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4.These results provided new insights into the pathogenesis of gout. Increased xanthine and hypoxanthine with decreased hydrocortisone provide promising biomarkers for gosling gout diagnosis. The findings suggested that hepatic metabolic disorders frequently occur in the development of avian gout.
1. This study examined different glycerol concentrations (GC) and freezing rates to improve the quality of rooster spermatozoa frozen in straws, and to determine the effect of varying GC on post-thawed spermatozoa quality, as evaluated by fertility and hatchability.
2.The experiment included two tests. In test 1, rooster semen straws containing 2, 4, 6, 8 and 11% glycerol were put in a rack (nine tiers with a 1 cm interval between every two tiers, 1 to 9 cm above liquid nitrogen (LN) source), and gradually frozen. The semen straws located in different tiers experienced different temperatures and freezing rates. The straws were then thawed and live sperm numbers determined. In test 2, rooster semen straws containing 2, 4, 6, 8 and 11% glycerol were put on optimal tiers (identified in test 1) for freezing, and stored at ?196°C. Hens were inseminated with the frozen semen (post-thawed and glycerol removed, about 4.0 × 108 sperm per hen), and eggs incubated.
3. The numbers of live sperm in the 11% glycerol group was higher than that in 2, 4 or 6% glycerol group (P < 0.05) for the semen straws on tiers 1 to 9, while that on tiers 1 to 5 was lower than that on tier 6 to 8 (P < 0.05). GC, freezing rate and the interaction between GC and freezing rate had a significant effect on live sperm numbers (P < 0.01). The highest fertility was in the 6% glycerol group and occurred on day 5 after insemination. The lowest fertility occurred in the 2% glycerol group on day 10 after insemination.
4. The optimal combination was 11% glycerol in straws located 6 cm above the LN surface (on tier 6). The 6% glycerol group achieved the highest fertility (77.6%), which surpassed that reported in recent years.
The types and methods of use of antibiotics in poultry farms in Cameroon, residual levels and potential microbial resistance were determined.
A questionnaire-based survey identified the different antibiotics used and high-performance liquid chromatography (HPLC) was used to determine residual levels of antibiotics.
Pathogens were isolated, identified by use of commercial API kits and minimum inhibition concentration (MIC) was determined.
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.
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.
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.
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.
This study examined the changes in eggshell strength and the genetic parameters related to this trait throughout a hen’s laying life using random regression.
The data were collected from a crossbred population between 2011 and 2014, where the eggshell strength was determined repeatedly for 2260 hens.
Using random regression models (RRMs), several Legendre polynomials were employed to estimate the fixed, direct genetic and permanent environment effects. The residual effects were treated as independently distributed with heterogeneous variance for each test week.
The direct genetic variance was included with second-order Legendre polynomials and the permanent environment with third-order Legendre polynomials.
The heritability of eggshell strength ranged from 0.26 to 0.43, the repeatability ranged between 0.47 and 0.69, and the estimated genetic correlations between test weeks was high at > 0.67.
The first eigenvalue of the genetic covariance matrix accounted for about 97% of the sum of all the eigenvalues.
The flexibility and statistical power of RRM suggest that this model could be an effective method to improve eggshell quality and to reduce losses due to cracked eggs in a breeding plan.
The aim of this study was to determine the antibiotic susceptibility of 93 Lactobacillus strains isolated from domestic geese raised on Polish farms. The minimal inhibitory concentration (MIC) of 13 antimicrobial substances was determined by the broth microdilution method.
All strains were sensitive to the cell wall inhibitors ampicillin and amoxicillin (MIC ≤ 8 μg/ml). Resistance to inhibitors of protein synthesis and to fluoroquinolone inhibitors of replication was found in 44.1% and 60.2% of isolates, respectively; 26.9% strains were resistant to neomycin (MIC ≥ 64 μg/ml), 23.6% to tetracycline (MIC ≥ 32 μg/ml), 15% to lincomycin (MIC ≥ 64 μg/ml), 18.3% to doxycycline (MIC ≥ 32 μg/ml), 9.7% to tylosin (MIC ≥ 32 μg/ml), 56% to flumequine (MIC ≥ 256 μg/ml) and 22.6% to enrofloxacin (MIC ≥ 64 μg/ml).
Bimodal distribution of MICs indicative of acquired resistance and unimodal distribution of the high MIC values indicative of intrinsic resistance were correlated with Lactobacillus species. Eleven (11.8%) strains displayed multiple resistance for at least three classes of antibiotics.
Data derived from this study can be used as a basis for reviewing current microbiological breakpoints for categorisation of susceptible and resistant strains of Lactobacillus genus and help to assess the hazards associated with the occurrence of drug resistance among natural intestinal microflora.
A total of 32 Lactobacillus isolates, 8 each from the crop (LGFCP1–LGFCP8), proventriculus (LGFP9–LGFP16), ileum (LGFI17–LGFI24) and caeca (LGFCM25–LGFCM32) were isolated from 25 adult guinea fowl (Pearl variety), 22–28 weeks of age, and characterised morphologically, physiologically, biochemically and by molecular methods.
Isolates were screened for their probiotic quality using range of in vitro tests: aggregation test, cell surface hydrophobicity, resistance to bile salts and acidic conditions, enzymatic tests and coaggregation and antagonistic test.
Based on in vitro test results and a novel scoring method, the two best isolates were selected and partial 16S rRNA sequencing was done. BLAST (Basic Local Alignment Search Tool) analysis of sequence of isolate LGFCP4 showed 99% genetic identity with Lactobacillus plantarum and LGFP16 with Lactobacillus reuteri.
The study shows that these two microbial agents may be suitable as potential probiotic candidates in guinea fowl, as well as in a feed supplement for other poultry species.
The aim of this study was to analyse the morphological lesion pattern of the heart of broiler chickens (Cobb 500, Hubbard F15 and Ross 308) during fattening with no clinical signs of disease and to determine the most susceptible period for the occurrence of morphological lesions.
The most frequently diagnosed lesions in each genetic line were degeneration of the fibres with vacuolation, congestion of cardiac muscle, oedema and vacuolisation of the Purkinje cells.
The highest numbers of morphological lesions were observed on d 38, 31 and 10 of life. The lesions were most numerous in the septum, followed by the left and right ventricles.
Ischaemic cardiomyocytes were also most numerous on d 38 of life and in the left ventricle.
Overload of cardiac muscle, prolonged hypoxia and increasing body weight on d 38 are the likely reasons for the largest number of lesions and ischaemic fibres, which may lead to heart failure.
In this study, the effect of chlorogenic acid extract from Lonicera japonica Thunb. on Mycoplasma gallisepticum infections and the performance of broiler flocks was investigated.
A total of 360 Ross-308 broiler chicks taken from M. gallisepticum seropositive flocks were divided equally into three groups designated as control (nothing administered), antibiotic (Tylosin tartrate given for the first 3 d and d 20–22) and test group (chlorogenic acid extract given twice a day on d 16 and 22).
Broiler performance analysis, serological tests (slide agglutination), molecular identification (polymerase chain reaction) and histopathological examination were performed to detect M. gallisepticum.
The results show that chlorogenic acid not only increases live body weight but is also an alternative treatment option in M. gallisepticum–infected broiler flocks.
The present study was conducted to compare the susceptibility of congenic Fayoumi lines to Eimeria tenella infection and to assess genetic differences in Eimeria egression.
Chickens were orally inoculated with 5 × 104 sporulated E. tenella oocysts and challenged with 5 × 106 oocysts on the 10th day after the primary infection.
The Fayoumi M5.1 line exhibited higher levels of body weight gain, less oocyst shedding and higher percentages of B and CD4+/CD8+ T cells than the M15.2 chickens.
These results demonstrate that M5.1 line is more resistant to E. tenella infection than M15.2 line. Furthermore, the percentage of sporozoite egress from peripheral blood mononuclear cells (PBMCs) was higher in the M5.1 line.
The results of this study suggest that enhanced resistance of Fayoumi M5.1 to E. tenella infection may involve heightened cell-mediated and adaptive immunity, resulting in reduced intracellular development of Eimeria parasites.
The objective of this study was to determine the genetic structure and variability of Bionda Piemontese and Bianca di Saluzzo (Piedmont, Northwest Italy) using an international set of microsatellite loci (AVIANDIV-FAO). Differences compared with commercial lines and other Italian breeds were verified to justify the implementation of conservation programmes.
Flock contribution to genetic variability was assessed following the approach implemented in the MolKin software. Comparison was performed using the fixation index and the Reynolds genetic distance. The most likely number of different populations was estimated using the clustering procedure implemented in STRUCTURE.
The molecular information suggests that management practices could have prevented random mating and produced inbreeding and heterogeneity across flocks. In this respect, Bionda and Bianca show substructuring and are more similar to British breeds than other continental European breeds.
Bionda and Bianca fit into the European breeds provided with the highest number of alleles and expected heterozygosity. There is a clear distinction between the Piedmont breeds and the other populations. The Piedmont poultry differ from both commercial lines and other Italian breeds and retain a high level of genetic variability.
As for other indigenous breeds, Bionda and Bianca could make an original contribution to the industry in the future. A collective planned approach to restoration is essential, because the flocks are managed with poor regulation. Enhancing connection between breeders with an efficient replacement interchange and mating plan is the right way of controlling inbreeding, preventing substructuring and increasing variability within the flocks.
Genetic parameters were estimated for 5 economically important egg production traits using records collected over 9 years in chickens reared under tropical conditions in Thailand. The data were from two purebred lines and two hybrid lines of layer parent stocks.
The two purebred lines were Rhode Island Red (RIR) and White Plymouth Rock (WPR) and the hybrid lines were formed by crossing a commercial brown egg laying strain to Rhode Island Red (RC) and White Plymouth Rock (WC), respectively.
Five egg production traits were analysed, including age at first egg (AFE), body weight at first egg (BWT), egg weight at first egg (EWFE), number of eggs from the first 17 weeks of lay (EN) and average egg weight over the 17th week of lay (EW).
Fixed effects of year and hatch within year were significant for all 5 traits and were included in the model.
Maternal genetic and permanent environmental effects of the dam were not significant, except for EN and EW in RIR and BWT and EW in WPR.
Estimated heritability of AFE, BWT, EWFE, EN and EW were 0.45, 0.50, 0.29, 0.19 and 0.43 in RIR; 0.44, 0.38, 0.33, 0.20 and 0.38 in WPR; 0.37, 0.41, 0.38, 0.18 and 0.36 in RC; and 0.46, 0.53, 0.36, 0.38 and 0.45 in WC lines, respectively.
The EN was negatively correlated with other traits, except for BWT in RC and AFE and BWT in WC.
It was concluded that selection for increased EN will reduce other egg production traits in purebred and hybrid chicken and therefore EN needs to be combined with other egg production traits in a multi-trait selection index to improve all traits optimally according to a defined breeding objective.
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A signal from a detector indicating departure from normality
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The interpretation of the signal (diagnosis)
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A feed-back signal to the origin of the detection signal indicating corrective action.
Two experiments were conducted to test the hypothesis that when using similar protein/amino acid diets and environment temperature conditions, the performance and carbon turnover in muscle and liver tissues, as measured by the incorporation of stable isotopes (13C/12C), must be different between fast-growing Cobb 500® and slow-growing Label Rouge broilers.
For both experiments (Cobb and Label Rouge), 21-d-old birds were distributed in a completely randomised, 3 × 3 factorial design; three environmental temperatures (cyclic heat stress ad libitum, 22°C ad libitum, and 22°C restricted) and three crude protein concentrations (189.1, 210 and 220 g/kg CP) were used.
The Cobb 500® had better performance with higher concentrations of crude protein. Cyclic heat stress (a temperature factor), negatively affected this genetic strain’s performance. For the Label Rouge birds, the crude protein concentrations in the diet presented inconsistent results and cyclic heat stress did not affect the performance.
The carbon turnover rate was affected in the Cobb 500® strain, with a high protein content reducing carbon turnover in the evaluated tissues (liver and muscles). Feed intake had a greater impact on carbon turnover rates than cyclic heat stress. The Label Rouge birds were not affected by the evaluated factors, suggesting that genetic improvement has a leading role on tissue carbon turnover.
There is a genetic influence on carbon turnover in the liver and muscle tissues of broiler chickens. In addition, genetically fast-growing broilers are more susceptible to variations in diet composition and environmental temperature than less rapidly growing animals.
The study documented gross anatomical and histological differences in the reproductive organs of 28 breeding and non-breeding female guinea fowls. Peripheral progesterone and 17β-oestradiol concentrations were also compared in breeding and non-breeding hens.
In non-breeding females, all ovarian and oviducal gross anatomical features had significantly regressed. Histologically, some of the changes in a regressing oviduct include systematic changes in height and size of all epithelial cells in all regions of the duct, absence/sparse ciliation of portions of surface epithelium in the magnum, isthmian and uterine regions, general loss of cytoplasmic mass, reduction in size and degeneration of tubular glands. Mucosal folds in all regions of the oviduct except the infundibular lip were higher in breeding females.
No difference was found between the two groups in plasma progesterone concentrations. Breeding females, however, had higher peripheral oestradiol concentrations than non-breeding females. About 2 h prior to oviposition, plasma oestradiol concentrations peaked at 2.4-fold (230 pg/ml) compared with baseline concentration and plasma progesterone concentrations by nearly 9-fold (5.29 ng/ml) of baseline.
Significant regression and changes in the histological structure of the ovary and oviduct had occurred in non-breeding females, and lower peripheral oestrogen concentrations may be responsible for this phenomenon.
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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;
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it varied linearly with the thickness of the shell;
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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;
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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);
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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;
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the existence of between‐strain differences in intercept constitutes prima facie evidence that the variation in this trait is under genetic control;
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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;
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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
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.
Mean haematocrit, haemoglobin and creatinine values were higher in the 1-year-old than in 10-year-old turkeys.
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.
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.
All male turkeys had higher haemoglobin and haematocrit values than age-matched females.
These data will help establish basic background references values in geriatric turkeys used in research.
Forty-two enrofloxacin-resistant Escherichia coli strains isolated from eggs and first-week mortality associated with yolk sac infection of two vertically integrated poultry companies of Central Mexico in 1997 and 2005 were characterised.
E. coli resistance to 19 antibiotics was determined, as well as the minimum inhibitory concentrations (broth dilution) for ciprofloxacin. The presence of gyrA,B, parC,E chromosomal point mutations, qnrA,B,S plasmid genes and the aminoglycoside acetyltransferase aac(6?)-Ib-cr were determined by PCR and sequencing.
Resistance to ampicillin (95%), piperacillin (95%), gatifloxacin (95%), levofloxacin (95%), ampicillin/sulbactam (90%), cefazolin (85%), trimethoprim/sulfamethoxazole (80%), amoxicillin/clavulanic acid (80%), aztreonam (80%), cefepime (80%), cefotaxime (80%), ceftazidime (80%), ceftriaxone (80%) and cefoxitin (75%) was high in the 2005 strains and 19 (95%) strains were resistant to 7 or more antimicrobials. The strains from 1997 expressed high rates of resistance only to the fluoroquinolones and 4 strains (18%) expressed resistance to 7 or more antimicrobials.
All strains had a gyrA mutation (Ser83Leu) and a parC mutation (Ser80Ile or Ser80Arg) and 41 (97.6%) strains had a second gyrA mutation (Asp87Asn, Asp87Tyr or Asp87Gly). Only two (4.7%) strains had a parE mutation (Ser458Ala). A total of 10 strains were positive for the aac(6?)-Ib wild-type gene, 6 strains for the aac(6?)-Ib-cr variant and 6 strains possessed both the wild type and the variant. No gyrB mutations or qnrA,B,S genes were detected.
This is the first report in Latin America of chromosomal and plasmid quinolone resistance genes in E. coli strains recovered from poultry.
1.?A study was conducted to study direct dominance genetic and maternal effects on genetic evaluation of production traits in dual-purpose chickens. The data set consisted of records of body weight and egg production of 49 749 Mazandaran fowls from 19 consecutive generations. Based on combinations of different random effects, including direct additive and dominance genetic and maternal additive genetic and environmental effects, 8 different models were compared.
2.?Inclusion of a maternal genetic effect in the models noticeably improved goodness of fit for all traits. Direct dominance genetic effect did not have noticeable effects on goodness of fit but simultaneous inclusion of both direct dominance and maternal additive genetic effects improved fitting criteria and accuracies of genetic parameter estimates for hatching body weight and egg production traits.
3.?Estimates of heritability (h2) for body weights at hatch, 8 weeks and 12 weeks of age (BW0, BW8 and BW12, respectively), age at sexual maturity (ASM), average egg weights at 28–32 weeks of laying period (AEW), egg number (EN) and egg production intensity (EI) were 0.08, 0.21, 0.22, 0.22, 0.21, 0.09 and 0.10, respectively. For BW0, BW8, BW12, ASM, AEW, EN and EI, proportion of dominance genetic to total phenotypic variance (d2) were 0.06, 0.08, 0.01, 0.06, 0.06, 0.08 and 0.07 and maternal heritability estimates (m2) were 0.05, 0.04, 0.03, 0.13, 0.21, 0.07 and 0.03, respectively. Negligible coefficients of maternal environmental effect (c2) from 0.01 to 0.08 were estimated for all traits, other than BW0, which had an estimate of 0.30.
4.?Breeding values (BVs) estimated for body weights at early ages (BW0 and BW8) were considerably affected by components of the models, but almost similar BVs were estimated by different models for higher age body weight (BW12) and egg production traits (ASM, AEW, EN and EI). Generally, it could be concluded that inclusion of maternal effects (both genetic and environmental) and, to a lesser extent, direct dominance genetic effect would improve the accuracy of genetic evaluation for early age body weights in dual-purpose chickens.