2. Four different alkaliphilic microbes were isolated and shown to degrade poultry feathers.
3. Two of the isolates were phylogenetically identified as Lysinibacillus and the others were identified as Nocardiopsis and Micrococcus.
4. The best microbial co-culture for white and black feather degradation was optimised for pH, temperature and relative population of the isolates to achieve almost 96% of degradation compared with a maximum of 31% when applying each isolate individually.
5. The maximum activity of keratinase was estimated to be 1.5 U/ml after 3 d for white feathers and 0.6 U/ml after 4 d for black feathers in a basal medium containing feather as the main carbon source. Additionally, non-denaturing polyacrylamide gel electrophoresis showed 4 and 3 protease activity bands for white and black feather, respectively.
6. This study provides a robust method to develop potential new mixtures of microorganisms that are able to degrade both white and black feathers by applying a Central Composite Design. 相似文献
2. In this study, keratin-degrading micro-organisms were isolated from a poultry farm. The predominant organisms were identified as Bacillus subtilis, Aspergillus flavus, A. fumigatus and Trychophyton sp.
3. The isolates were inoculated into feather medium and observed for keratin degradation by measuring the protein content, free amino acids and change in pH.
4. During feather degradation by B. subtilis, the concentration of soluble protein released to the medium increased gradually and reached the maximum (433 µg/ml) during d 7 of incubation and the pH increased from the initial 6.9 to 8.4 on d 9 of incubation. Similarly, the maximum protein content of 414 µg/ml and pH of 8.5 was observed for A. fumigatus on d 21 of incubation.
5. B. subtilis and A. fumigatus showed almost the same level of keratinase activity. 相似文献
2. There were some differences between the two ages; these could largely be reconciled by considering the likely differences in the proportion of feather protein.
3. The results were compared with similar values for the chicken and goose; overall there is a striking similarity, both in absolute concentrations and relative proportions of amino acids. 相似文献
2. DNA was extracted from 65 confirmed APEC E. coli from chicken, 100 presumptive commensal E. coli from healthy turkey and 35 from healthy chicken. Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and virulence factors genotyping was performed to characterise genetic features.
3. Carbon source utilisation and antimicrobial susceptibility tests were performed to characterise phenotypic features of isolates.
4. The genetic divergence between E. coli strains tested by ERIC-PCR profiles and virulence-associated genes showed a clear genetic separation between E. coli APEC and turkey E. coli strains.
5. The carbon utilisation profile of turkey isolates was different from chicken and APEC strains; whereas antimicrobial susceptibility was highest for turkey isolates (53%), and lowest for APEC strains (33.8%).
6. The study showed a significant negative correlation between utilisation of arabitol and adonitol with different virulence determinants tested, which suggests that the ability to utilise some uncommon carbon sources may be used to discriminate between presumptive commensal E. coli and APEC. 相似文献
2. A simple technique for chicken manipulation is eggshell windowing, without or with seal, the latter having demonstrated some improvement in hatching rates.
3. Likewise, a surrogate eggshell system provides an accessible model for manipulation during chicken and quail development, with a higher hatchability compared to the simple windowing method.
4. The development of the chicken ex ovo culture systems in a synthetic environment as an efficient technique for imaging and microsurgery applications has enabled the study of important events of live chicken embryos at a specific time point.
5. This short review illustrates recent applications of well-designed whole embryo culture systems as a robust model for research into numerous biological mechanism, drug discovery, gene manipulating and production of functional proteins. 相似文献
2. A total of 20 one-day-old Leghorn chicks (slow-growing) and 20 broiler (Ross 508) chicks (fast-growing) were reared to 100 and 45 d, respectively.
3. A small percentage of GF was seen in pre rigor muscle samples even at 3 min post mortem in both genotypes and in all muscle types studied.
4. From 3 min to 24 h post mortem GF increased both in Leghorn and broiler chickens but to a different extent according to muscle type and genotype.
5. The highest GF 24 h post mortem value was found in the PM muscles belonging to the fast-growing broiler line.
6. It was concluded that every type of muscle can develop GF, but this phenomenon is more evident in the PM especially in animals selected for increased growth rate. 相似文献
2. A total of 12 haplotypes were found in Cornish, control layer and Aseel breeds of chicken in which the h1 haplotype was most frequent.
3. Nucleotide substitutions among haplotypes were found at 21 positions in the IGF1 gene in which 4 substitutions resulted in non-synonymous mutations in the receptor binding domain of the IGF1 protein.
4. The haplogroup showed a significant effect on body weight at 24 and 42 d of age in the control layer line, body weight at 42 d and daily weight gain between 29 and 42 d in the control broiler line, daily weight gain between 29 and 42 d in Cornish, and body weights at 42 d as well as daily weight gain between 29 and 42 d in Aseel birds.
5. IGF1 expression varied among the breeds during embryonic and post-hatch periods. The expression among the haplogroups varied in different chicken tissues. The effect of haplogroup on myofibre number in pectoral muscle was non-significant, although there was significant variation in numbers between d 1 and d 42, and between broiler and layer lines.
6. It was concluded that the coding region of the IGF1 gene was polymorphic, expressed differentially during the pre-hatch and post-hatch periods, and haplogroups showed significant association with growth traits in chicken. 相似文献
2. Half the hens had undergone beak trimming at 18 weeks, but in many cases regrowth had occurred.
3. Plumage damage and loss was significantly reduced in beak‐trimmed birds compared with birds with normal beaks. Tier and cage design had no effect.
4. This finding supports the idea that feather pecking is the important factor in causing plumage damage, rather than abrasion.
5. A comparison between 64 birds in which beak regrowth had occurred, and 64 in which it remained truncated, showed that both groups had similar plumage scores.
6. It appears to be the beak‐trimming procedure which is important; subsequent regrowth being irrelevant. 相似文献
2. Although the protein content of all tissues varied with age, the only statistically significant effect was on the level of protein in the gizzard.
3. The moisture content of the gizzard was significantly affected by age and blood by age and sex.
4. The fat content of the gizzard was significantly affected by age, as was the effect of sex on the fat content of blood.
5. The ash contents of heart and gizzard were significantly affected by age.
6. The phosphorus contents of the gizzard, heart and liver were significantly affected by age, as were the chloride content of heart and the calcium content of the liver. Blood potassium was significantly affected by sex. Fluctuations in the contents of other elements are discussed.
7. The variability in organ composition is discussed with respect to the degree of trimming and preparation of the samples. 相似文献
2. Developmental changes of gene expression of xanthine oxidoreductase (XOR), XO activity and UA content of liver and kidney tissues in both broiler and layer chicken embryos were examined during incubation d 14–21.
3. In both strains, hepatic XOR gene expression peaked on d 21 while renal XOR gene expression did not change.
4. The XO activity was higher in kidney than liver in both strains. Hepatic XO activity of both strains peaked on d 18 and thereafter was decreased on d 21. Renal XO activity peaked on d 18 and from then on did not show any significant changes until d 21 in both strains.
5. The UA content was higher in kidney vs. liver in both strains. The hepatic and renal UA values of the both strains increased significantly from d 14 to d 21.
6. The present results showed dissimilar behaviour of XOR gene expression, XO activity and UA content of liver and kidney tissues in both broiler and layer chicken embryos. 相似文献
2. In the first experiment, 144 pullets, 72 each of Ff and ff pullets from F1 birds, were compared in a randomised complete block design (RCBD), with three villages and 4 batches of hatch as blocks and the two feather genotypes (Ff and ff) as the treatments.
3. The Ff pullets were superior (P < 0.05) to their ff counterparts in terms of the number of eggs per clutch, egg mass and hen-housed and hen-d rates of lay, whereas age at first egg was lower (P < 0.05) in ff layers compared to Ff ones.
4. The eggs of the F1 heterozygous frizzle (Ff) layers had higher values for albumen height, Haugh unit and yolk height compared with eggs from their normal feathered counterparts.
5. In the second experiment, 144 pullets, 48 each of FF, Ff and ff pullets, were compared in a RCBD, with three villages and 4 batches of hatch as blocks and the two feather genotypes (Ff and ff) as the treatments.
6. The F2 birds with genotypes Ff and FF were better than their ff counterparts in terms of the number of eggs per clutch, egg mass, and hen-housed and hen-d rates of lay. Age at first egg was significantly lower in ff layers compared to FF and Ff ones.
7. The Haugh unit value was higher in the homozygous and heterozygous frizzles compared to the normal feathered ones.
8. The presence of the frizzle gene (F) in egg type chickens led to an improvement in egg production and egg quality traits in village chickens, and the cross-breeding scheme evaluated in this project could contribute to improved productivity. 相似文献
2. The poults were free from contamination on arrival at the rearing house but were contaminated via the water supply from troughs which had been ineffectively fumigated.
3. Foodstuffs did not appear to be a source of contamination.
4. The spread of salmonellae in this turkey rearing enterprise was very similar to that in chicken rearing houses. 相似文献
2. Ornithobacterium rhinotracheale is a bacterium associated with respiratory tract infections in poultry. The mechanisms by which O. rhinotracheale causes infection are not known. To date, at least 18 serovars of this bacterium, with or without the ability to agglutinate erythrocytes of chicken and other species, have been identified.
3. The purpose of this work was to evaluate the ability of five references strains, belonging to serovars A, B, C, D and E, to adhere to a culture of primary chicken tracheal cells.
4. Serovars A and B adhered to less than 20% of tracheal cells with no specific adherence pattern. Serovars C, D and E gave adherence values greater than 70%. Serovars C and E showed a diffuse adherence pattern, while serovar D had an aggregated adherence pattern.
5. The adherence ability and pattern could be associated with different pathogenicity mechanisms in the various serovars but more studies are needed to understand the reasons for these differences. 相似文献
2. Among the 11 chicken tissues examined, the feather bulb, comb and skin showed higher levels of all TYR variants. All TYR variants were expressed at significantly different levels in black and white feather bulbs (P < 0.05) and may be involved in melanin formation in plumage. Only TYR-AS1, which plays an important role in muscle melanogenesis, was significantly differentially expressed between black and white muscle (P < 0.01). All TYR variants were expressed at significantly different levels in black and white skin (P < 0.01).
3. The mRNA expression levels of the 5 variants were closely associated with skin melanogenesis in the chicken. These findings provide new clues to the molecular mechanism of melanin formation in the Muchuan black-boned chicken. 相似文献
2. In a completely randomised design, different probiotic strains were injected into the amniotic fluid of the 480 live embryos (d 18 of incubation), with 4 treatments and 5 replicates. Ileal MUC2 gene expression, microbial profile, growth performance and immune response were determined.
3. Injection of probiotic strains, especially B. subtilis, had significant effect on expression of the MUC2 on d 21 of incubation and d 3 post-hatch, but not on d 19 of incubation.
4. Injection of the probiotic strains decreased significantly the Escherichia coli population and increased the lactic acid bacteria population during the first week post-hatch.
5. Inoculation of probiotics had no significant effect on antibody titres against Newcastle disease virus, antibody titres against sheep red blood cell and cell-mediated immune response of chickens compared to control.
6. In ovo injection of the probiotic strains had no significant effect on growth performance of broiler chickens.
7. It was concluded that injection of probiotic bacteria especially B. subtilis into the amniotic fluid has a beneficial effect on ileal MUC2 gene expression and bacteria population during the first week post-hatch, but has no effect on growth performance and immune response in broiler chickens. 相似文献
2. A circadian system was postulated to control the restriction of ovulation to an 8‐h period of the day under conventional 14 h light: 10 h dark regimes.
3. The final phase of follicular maturation was postulated to commence after ovulation of the preceding ovum in the hierarchy.
4. Ovulation was postulated to occur when a mature follicle was present in the ovary during the appropriate phase of the circadian‐linked system.
5. The predicted times of oviposition were within the standard error of the observed times of oviposition under 21‐, 24‐ and 28‐h photoschedules.
6. It was concluded that this hypothesis for the control of the ovulatory cycle of the hen is consistent with current knowledge. 相似文献
2. Restricted birds were lighter throughout the experiment.
3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.
4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.
5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.
6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found. 相似文献
2. No difference was found in the qualitative electrophoretic patterns of the anterior pituitary homogenates at different ages and between the sexes.
3. Pituitary PRL concentrations in males were generally higher than in females.
4. Pituitary PRL concentrations in castrated immature cockerels were higher than in intact birds, while PRL concentration was depressed by the injection of testosterone propionate or oestradiol benzoate.
5. Prolactin concentration in intact immature cockerels was decreased by daily injection of testosterone or oestradiol for 3 weeks but not by injection of the hormones for 1 week. 相似文献
2. Eighty broilers were randomly divided into two groups. Birds in the control group were fed on maize–soybean-based diets. Birds in the treatment group were provided the same diet supplemented with 2 g/kg BA encapsulated in a vegetable oil matrix.
3. At the end of the trial (d 35), pH, bacterial composition and metabolites were determined in the crop, jejunum, ileum and caecum.
4. Growth performance variables and pH were not significantly different.
5. BA concentration decreased rapidly in the proximal gut. However, the treatment diet showed higher BA in the crop, jejunum, ileum and caecum.
6. Total lactate in the crop and D-lactate in the jejunum was higher in the BA treated group. Caecal total and branched chain fatty acids were decreased due to the treatment.
7. Lactobacilli populations were significantly altered by BA supplementation. A trend for increased lactobacilli was observed in the crop, while it became significant in the jejunum and ileum. Lactobacillus species responded differently to the treatment. Four of 5 measured Lactobacillus species, particularly in the ileum, followed the course observed for total lactobacilli; only Lactobacillus salivarius was not modified.
8. Correlation analysis showed that BA modified the intestinal microbiota. Lactobacilli correlated negatively to all studied clostridial clusters and enterobacteria. Clostridial clusters IV and XIVa were significantly increased in the jejunum, whereas only clostridial cluster XIVa was increased in the caecum.
9. Encapsulated BA modified the intestinal microbiota which can lead to the conclusion, that the main beneficial mode of action of BA in the gut appears to be the enhancement of lactic acid bacteria, which in turn may act as a vanguard against pathogens. 相似文献