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 62 毫秒
1.
1. The fermentation of poultry manure in an attempt to increase its value for poultry diets was studied.

2. Microbial strains for the efficient elimination of uric acid were isolated.

3. Suitable, cheap carbon sources (methanol, glycerol, glucose) were tested in attempts to increase cell yield.

4. These criteria were used to study the 41 bacterial and 8 yeast strains which were the most prolific on slants and which were isolated from experiments with a shaker. A strain was selected for experimentation with a fermentor.

5. Fermentor experiments were done on a laboratory scale (101) and in a non‐sterile semicontinuous system (150 1), cell mass production being similar in both systems.  相似文献   


2.
1. The dietary inclusion of 15 and 25 g/kg mannose was associated with a reduction in the numbers of Salmonella enteritidis (PT4) in the caecal contents of chicks challenged by the food. The same benefit was not recorded for S. infantis, possibly because this strain, unlike S. enteritidis PT4, lacked mannose‐sensitive fimbriae.

2. The addition of 25 g/kg palm kernel meal (PKM), but not 20 g/kg desiccated coconut, to the food reduced the degree of salmonella colonisation in the intestinal tract of broiler chicks given diets contaminated with S. kedougou or S. enteritidis from the day of their arrival from the hatchery.

3. The beneficial effect of PKM was also demonstrated at an inclusion rate of 5 g/kg and was similar for preparations with a particle size of either < 150 μm or < 300 μm.

4. Day‐old birds challenged orally with S. enteritidis and given food supplemented with 25 g/kg PKM, became clear of infection by 3 weeks of age while birds given unsupplemented food remained infected.

5. These preliminary results suggest that the inclusion of PKM, which contains inter alia, oligosaccharides containing mannose, in the diet of chicks may reduce the extent to which the intestine is contaminated with salmonellas.  相似文献   


3.
A systemic insecticide carbaryl and a fumigant insecticide dichlorvos were investigated for the control of Dermanyssus gallinae and Liponyssus sylviarum.

The blood of birds given single doses of 200–400 mg./kg. carbaryl was toxic to mites for up to 2 days, but it was found necessary to continue treatment for up to 17 days in order to control the mites.

Dichlorvos emitted from a plastic “ Vapona “ strip and from an aqueous spray did not penetrate crevices and failed to control the mites.

It was concluded that the systemic and fumigant insecticides investigated had no advantage over the normal contact insecticides for the control of poultry mites.  相似文献   


4.
1. In the years 1985 to 1989 decisions (approvals and condemnations) made by poultry meat inspectors were examined by the individual reinspection of 26,815 broiler carcases.

2. The extent of agreement between inspection and revision ranged between 83.2 and 86.2%.

3. Agreement between inspectors and revisors was higher for the category of approved birds than for the condemned category.

4. Differences in the criteria used to assess the birds were observed.

5. The conclusion was drawn that findings in meat inspection require further discussion to reach an agreed standard.  相似文献   


5.
1. The objective of this study was to evaluate the effects of dry-ice decontamination on equipment and carcase surfaces in a poultry slaughterhouse and to present an effective alternative method to the conventional decontamination processes.

2. Appreciable reductions occurred in total aerobic mesophilic bacterial counts of surface swab samples treated with dry ice (maximum difference 3.92 log cfu/100 cm2).

3. After dry-ice treatment, Listeria spp. were detected on surfaces of pluckers and chiller cylinders, whereas Salmonella spp. were totally inhibited.

4. A dry-ice spraying application was more effective than a dry-ice immersing application on total aerobic mesophilic bacteria and yeast and mould counts on poultry carcases.

5. Dry-ice treatment has advantages over conventional processes. Unlike other decontamination techniques, there are no residues, so no need to wash off chemical residues from surfaces as it removes contaminants effortlessly and is environmentally friendly.

6. Dry-ice blasting of production equipment can reduce the microbial load and has potential for use in the poultry industry.  相似文献   


6.
1. Dried poultry manure (DPM) has been tested as a replacement for groundnut cake in poultry diets.

2. Body weight gain, and the efficiency of food conversion were improved when the diet contained 50 g DPM/kg but higher rates of inclusion (100 or 150 g/kg) depressed growth.

3. Birds fed on diets containing 50 g DPM/kg yielded meat of comparable quality to those fed on the control diet whereas those fed on diets containing more DPM yielded meat containing more fat and less water.

4. The percentage moisture in the meat was inversely related to the lipid content.

5. Nitrogen retention was comparable in all groups.  相似文献   


7.
1. Poultry keeping in the UK hardly existed as an industry of any sort prior to the 1890s. Annual consumption per capita was 100 eggs and around 1000 M eggs were imported from countries all over the world.

2. The Utility Poultry Club was formed in 1897 and shortly afterwards the first laying trial was held near Northallerton.

3. Until 1920 little was done in the way of giving advice or training to poultry keepers or farmers, but in that year the National Institute of Poultry Husbandry was set up at Harper Adams College.

4. Egg marketing was a haphazard affair until in 1929 a National Mark Scheme was devised in an attempt to streamline distribution, so that UK eggs could compete with foreign imports, some of which were marketed here fresh, clean and graded. This could not be said for the bulk of home produced eggs until that time.

5. With the practical application of the science of genetics to poultry breeding the concept of the simple laying trial gave way to progeny test trials. By 1986 these have become international rather than national—a reflection of the international nature of the breeding industry.

6. The pattern of poultry diseases has changed radically in the 40 years since 1945. The growth of intensive and controlled environment housing produced its own problems, which the industry has largely learned to control.

7. The pre‐war table poultry industry was largely based on a premium product specially bred from such birds as Light Sussex, Dorkings and Faverolles and, at the lower end of the market, surplus cockerels from the commercial layer trade were used. The broiler industry was born around 1954 with the end of feedings tuff rationing.

8. The illustrations trace the development of extensive housing and also some early cage units which, until the early 1950s, were always single bird cages.

9. A brief paragraph is included on the history and development of the turkey industry; it is included to demonstrate its parallel development with the broiler industry, but would merit a paper of its own.  相似文献   


8.
1. Two hundred and sixty four dwarf broiler breeder hens were subjected to ad libitum or restricted feeding and to four lighting patterns: 15L (bright light):9D (dark), 15L:9d (dim light), 2L:10d: 1L:11d, (0.5L:3.5d) × 6.

2. Breeder hens fed ad libitum and subjected to either conventional or intermittent lighting ingested respectively, 25 g and 14 to 17 g more than hens restricted to 115 g/d.

3. Body weight was greater in hens fed ad libitum irrespective of the lighting pattern and of the amount of food intake.

4. Persistency of egg production was impaired by intermittent lighting.

5. Ad libitum feeding reduced egg fertility. The decrease was larger in breeder hens on intermittent lighting.

6. Hatchability was increased in hens submitted to the symmetrical lighting pattern (0.5L:3.5d).

7. Egg and chick weights were higher in hens fed ad libitum.

8. Shell index and shell breaking strength increased in restricted hens on the intermittent lighting pattern (0.5L:3.5d) × 6.

9. The best performance was obtained in restricted hens on the conventional lighting pattern.  相似文献   


9.
1. Dried poultry manure (DPM) collected from 1‐d to 3‐week‐old chicks, reared in electrical battery brooders, incorporated at a level of 0, 5, 10, 15 and 20% in a chick starter diet, was recycled four times.

2. There was a linear decrease in body weight and efficiency of food utilisation with each percentage increase in DPM.

3. The amount of dried droppings recovered as a percentage of food consumed was proportional to the amount of DPM included in the diet and remained fairly constant during the recycling.

4. Body weights and efficiency of food utilisation were substantially the same during the first three recycling periods but declined significantly during the fourth period.

5. Mortality was negligible and all chicks appeared healthy and vigorous.

6. Chicks fed on 10% DPM in an isocaloric and isonitrogenous (protein‐N) diet grew and utilised food as well as those fed on the basal diet; chicks fed on 20% DPM did not consume enough to meet their requirements.  相似文献   


10.
1. The effect on food consumption by pullets when dried poultry manure (DPM) replaced part of dietary groundnut cake depended on the strain of the birds: in two of the three hybrids food consumption was not affected when up to 100 g DPM/kg was fed.

2. Increases in food consumption were accompanied by increases in egg production.

3. The food required per dozen eggs was improved by up to 100 g dietary DPM/kg and variation in the sizes of eggs laid depended on the hybrid.

4. Concentrations of DPM up to 100 g/kg did not affect the water‐soluble nitrogen content of the egg but the crude albumen nitrogen content was depressed at concentrations of 80 g/kg or above.

5. Feeding DPM to laying pullets depressed body weight.  相似文献   


11.
1.?Potato pulp is the industrial waste produced during starch extraction from potatoes. Its discharge has become an environmental pollution problem and a decisive cost factor due to stricter environmental legislation and associated expense in the potato starch industry.

2.?To date, little information has been provided regarding the nutritive value and any possible toxic effects of potato pulp for poultry feed.

3.?In the present paper, a model was developed to assess potato pulp for use as a new poultry feed, which will help starch factories to decrease waste discharge.

4.?First, a solid-state fermentation technique to change potato pulp to poultry feed is briefly described; then, the major nutrient compositions of this feed are analysed; lastly, related toxicological effects are studied and the safety of the feed assessed.

5.?The results indicated that no unintended effects were found on layer quails during a 30-d feeding study, and the new feed initially showed its safety for poultry in our assessment procedure. However, additional work on limiting nutrients analysis, appetite depressant effects, and egg-laying in a large-scale experiment is required to further establish the findings.  相似文献   


12.
1. Bacteriophages (BP) have gained increasing attention as a treatment of bacterial infection for animals. However, the data pertaining to dietary application of BP for laying hens have been limited.

2. This study aimed to investigate the effect of dietary BP on laying performance, egg quality and caecal bacterial populations in laying hens.

3. The dietary BP used in this experiment was a mixture of individual BP targeting Salmonella gallinarum, Salmonella pullorum, Salmonella typhimurium, Salmonella enteritidis, Salmonella derby and Staphylococcus aureus.

4. A total of 360 Hy-Line Brown laying hens of 32 weeks of age were allotted to one of three dietary treatments with 6 replicates in a completely randomised design. The basal diet was prepared, and 0.4 or 0.8 g/kg BP mixture was supplemented to the basal diet. Diets were fed to hens for 8 weeks.

5. Laying performance and egg quality were not affected by dietary treatments. As inclusion levels of BP mixture in diets were increased, the DNA copy numbers for Salmonella spp. in the caecal contents decreased linearly, whereas the DNA copy numbers for Escherichia coli in the caecal contents increased linearly.

6. Results indicate that dietary supplementation of BP mixture decreases the target Salmonella spp. populations but increases Escherichia coli populations in the gastrointestinal tract of laying hens with little impact on laying performance and egg quality.  相似文献   


13.
1. This paper reviews the use of botanical extracts in the control of coccidial infection in poultry.

2. Some plants and their respective volatile oils and extracts have the potential to alleviate coccidiosis and reduce its severity.

3. Most plant bioactives improve some, but not all, aspects of coccidiosis with variable effectiveness against different species of Eimeria.

4. Difficulties in comparing research findings have arisen from the use of different experimental models, different active components and infectious dose of Eimeria.

5. Current knowledge of their potential anti-coccidial effects may provide guidance for the use of botanical extracts in the control of the coccidiosis.  相似文献   


14.
1. The efficiency of the AvGard? (or Assur‐Rince? in the USA) trisodium phosphate poultry carcase decontamination process was evaluated during both manual and industrial trials against total aerobic mesophilic count (TAMC), thermotolerant coliforms, Pseudomonas, Enterobacteriaceae, Campylobacter, Listeria monocytogenes and Salmonella.

2. The TSP treatment proved to have significant effects on the bacterial decontamination of poultry neck skin, lowering the contamination by a factor of about 10 for TAMC and of 100 for Coliform and Pseudomonas.

3. Numeration of Salmonella with an innovative miniaturised most probable number method has proved that the effect upon these micro‐organisms was also close to 2 log10 reduction.

4. The effect of TSP treatment on the ecological balance of psychrotrophic bacterial flora was also investigated to study the origin of the shelf‐life flora of treated carcases (Pseudomonas being reduced to the limit of detection) and to ascertain whether L. monocytogenes might gain a competitive advantage. In fact AvGard? reduced the number of L. monocytogenes on poultry carcases.

5. As a consequence of the virtual elimination of the Pseudomonas usually present, Brochothrix thermosphacta became the main species responsible for putrefaction.

6. Because the growth rate of Brochothrix thermosphacta was greater than that of L. monocytogenes at refrigeration temperature, it was considered that putrefaction would occur before the emergence of large numbers of L. monocytogenes.  相似文献   


15.
1. The distribution of survivor egg production has been examined in four control strains of White Leghorn egg laying chickens, a strain of turkeys and a strain of ducks.

2. The most pronounced trend was a persistent negative skewness (an excess of poor producers) associated with a positive kurtosis (an excess of individuals about the mean) and a marked deficiency of high producers.

3. Truncation of these populations at two or one phenotypic standard deviation below the mean tended to reduce the asymmetry but at the expense of the kurtosis which frequently became significantly negative.

4. The greatest departures from normality were observed in the earlier parts of the recording period.

5. A considerable degree of heterogeneity of variance among hatches within strain/years was observed and it is considered that this is largely due to the asymmetry.

6. Negative skewness in the distribution of egg production appears to be a widespread phenomenon and is considered to be due more likely to non‐random environmental factors than fixation of recessive genes.

7. Predictions of progress based on the normal curve must tend to overestimate what is realised and the abnormality observed, which appears to be general, must have negative implications for the accuracy of estimation of biological parameters.  相似文献   


16.
1. The sources and numbers of microbes contaminating poultry portions, which form an increasing proportion of poultry meat production were investigated. Total aerobic count at 30°C, pseudomonads, coliforms, enterococci and Staphylococcus aureus were enumerated.

2. Samples which had undergone different degrees of portioning, from whole birds to individual retail portions of poultry meat, were collected at points along the portioning line. Equipment surfaces, utensils and hands/gloves of factory personnel were examined.

3. In general, microbial numbers on carcase sampling sites were related to ‘exposure factor’, that is, the length of time the site was exposed to potential contamination during processing and portioning.

4. When results for individual sampling sites were analysed separately, no significant differences were found between sites on whole birds and the corresponding half bird sample sites. Comparison of numbers on half birds and on portions revealed a more variable situation.

5. Sites touched by rubber gloves when carcases were hung on the automatic portioning lines had greater contamination than other sites.

6. Provided factory and operative hygiene standards are high, portioning does not significantly increase numbers of microorganisms.  相似文献   


17.
1. A number of factors causing variability in the percentages of cracked, and dirty eggs and weekly standard margin (WSM) of returns from eggs over production costs were examined on an integrated commercial poultry plant in Scotland.

2. As the bird aged, the percentage of cracked eggs increased (P <0.01) and the percentage of grade A eggs and WSM decreased (P <0.01). Cracks in dirty eggs (10.1%) were more than double those in all eggs laid (4.9%).

3. Seasonal effects on percentage cracked eggs and percentage grade A eggs were one‐third the magnitude of those due to age but were significant (P <0.05).

4. Variability in percentage cracked eggs, dirty eggs and WSM accounted for by the factors measured, were 72, 64 and 92% respectively.

5. The variability in WSM was significantly affected by percentage lay, food consumption and age but not by percentage cracked eggs, originally dirty and grade A eggs.

6. Flock management and climate inside the laying house each increased the amount of variability accounted for in the percentage cracked eggs and dirty eggs by at least 10%.  相似文献   


18.
1. Large doses of tungsten, administered to the chick either by injection or by feeding, increased tissue concentrations of tungsten and decreased tissue concentrations of molybdenum and tissue activities of xanthine dehydrogenase.

2. The rate of loss of large doses of tungsten from the liver occurred in an exponential manner with a half‐life of 27 h.

3. When tungsten was administered to chicks fed on a semi‐synthetic diet containing abnormally low concentrations of molybdenum, the activity of hepatic xanthine dehydrogenase was reduced to negligible levels.

4. The alterations in molybdenum metabolism resulting from the administration of large doses of tungsten to the chick appears to be the result of tungsten toxicity and not of molybdenum deficiency.

5. Deaths from tungsten toxicity occurred when tissue concentrations of tungsten were increased to approximately 25 μzg/g liver. At this tissue tungstencon centration the activity of xanthine dehydrogenase was zero.  相似文献   


19.
1. The occurrence of Arcobacter spp. and three pathogenic species of Arcobacter from Iranian poultry carcasses was investigated at different steps of broiler processing to determine critical control points for reducing carcass contamination.

2. Samples were collected from (a) cloaca immediately before processing, (b) different points during processing and (c) at different stations in a processing plant of a slaughterhouse in southern Iran.

3. After enrichment steps in Arcobacter selective broth, DNA of the samples was extracted and three significant pathogen species of Arcobacter were identified based on polymerase chain reaction (PCR) detection of 16S rRNA and specific species PCR.

4. Out of a total of 540 samples, 244 (45%) were positive for Arcobacter spp. Arcobacter butzleri was more frequently detected (73% ± 13.9%) than A. cryaeophilus (9% ± 13.9%) and A. skirrowii (4.1%). In addition, co-colonisation (A. butzleri and A. cryaerophilus) occurred in 13.9% of the positive samples.

5. The results indicate a high prevalence of Arcobacter in the investigated slaughterhouse and broiler carcasses and that Arcobacter is not a normal flora of the broilers. Evidence for the presence of Arcobacter in the environment and water of processing plants suggests that these are sources of contamination of poultry carcasses. In addition, contamination of the poultry carcasses can spread between poultry meats in different parts and processes of the slaughterhouse (pre-scalding to after evisceration).  相似文献   


20.
1. Genetically fat and lean adult broiler breeder females were fed ad libitum or restricted throughout life. At one year of age, comparisons of blood viscosity and haematology and changes in blood chemistry after exposure to thermal stress were conducted.

2. Whole blood viscosity was more than twice as high, and plasma triglyc‐eride and haemoglobin concentrations were over 30% higher in fat line than in lean line females fed ad libitum or in restricted birds of both genotypes.

3. Mean cell haemoglobin concentration was higher and mean cell volume lower in fat compared with lean line females.

4. Food restriction was associated with lower plasma triglyceride concentrations, lower numbers of heterophils and monocytes and a lower heterophil‐lymphocyte ratio.

5. Fat line birds had a higher blood pCO2 and lower pH than lean line birds.

6. Thermal stress was associated in ad libitum‐fed birds with a rise in blood pH and a decrease in pCO2, and in restricted birds with a decline in blood pH and an increase in pCO2.

7. Blood creatine kinase activity increased in all groups under thermal stress.  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