Determining of heat balance design criteria for laying hen houses under continental climate conditions

This study focuses on the heat balance status of laying hen houses in regions with continental climate. The material consists of 45 laying hen houses from 27 commercial farms selected from the survey area where continental climate prevails. These laying hen houses differ from each other with respect to capacity, planning system and materials used in construction. First observations were conducted on the size and dimensions of laying hen houses as well as construction materials used, insulation, heat loss factors, ventilation capacity, ground space per hen and total size of laying hen house in order to assess the sufficiency of heat balance. Then, seven laying hen house models were developed. These models were developed by considering the present situation in operating laying hen houses, relevant literature, features of continental climate and suggestions made by firms manufacturing laying hen house construction materials in Turkey. These models give heat conduction coefficients that will prevent moisture concentration and ensure heat balance under continental climate conditions and suggest different sets of materials that can be used on walls and roofs. At the end of the study, under the condition of no moisture on surface of structural components and in areas where the indoor and outdoor temperatures are 25.3 °C and 20.2 °C, respectively, maximum total heat conduction coefficients are calculated to be between 1.38 and 1.73 Kcal/m² °C h. According to the features of area and housing, for providing heat balance, total heat conduction coefficients requirements are calculated to be between 0.62 and 2.08 Kcal/m² °C h for walls, 0.33 and 1.62 Kcal/m² °C h for roofs. In research area, minimum ventilation capacities are determined as 0.72 m³/h hen for carbon dioxide balance and, according to outdoor temperature, as 0.83–1.20 m³/h hen for water vapor balance. Heat loss factors are calculated to be between 0.10 and 0.15 Kcal/°C h hen. We believe that these suggestions will greatly facilitate the work of project engineers in the design of laying hen houses in regions and areas with continental climate.     

Verifying the geographical origin of poultry: The application of stable isotope and trace element (SITE) analysis

Stable isotope and elemental analysis, together with statistical processing of the resultant data has been used to determine the geographical origin of poultry and hence provide a means to verify poultry labels originating from major producing countries/regions. Multivariate statistical analysis has demonstrated that 18 variables, including carbon, hydrogen and nitrogen stable isotope ratios and elemental concentrations of magnesium, thallium, rubidium and molybdenum, are important parameters in poultry origin determination. Using cross-validated discriminant analysis 88.3% of poultry geographical origins were correctly classified (n = 339). Individual correct-classification rates were as follows; China, 100% (n = 36); Brazil, 94.1% (n = 101); Europe 92% (n = 87); Chile 82.6% (n = 46); Thailand, 70.3% (n = 46) and Argentina 50% (n = 10). The main identification errors were associated with miss-classification of Argentinean samples with those originating from Chile and Thailand. Carbon stable isotope ratios of chicken meat indicate the quantity of maize in the diet and this leads to useful discrimination between a large proportion of European poultry and poultry reared in locations such as South America, Thailand and China where maize feeding predominates. The use of poultry carbon isotope values as a simple ‘screening’ parameter to differentiate European poultry meat from other major importers is not as reliable as for the differentiation of European and South American beef. However carbon isotope ratios will be useful in most instances to corroborate suspicion of mislabelling of non corn-fed European poultry. The stable isotopes of hydrogen and oxygen in chicken meat change in a similar way to surface waters around the globe. Our findings support the hypothesis that the global isotopic variation of stable isotopes in drinking water and feed are transferred into animal tissue and can be used to help establish an animal's geographic origin. This is a significant finding and mirrors our observations for beef skeletal muscle δ²H ‰ and δ¹⁸O ‰ values. These systematic variations can be exploited to give a ‘low-resolution’ indication of an animal's geographic origin (e.g. Northern Europe versus the tropics).     

Consumption and production waste: another externality of tobacco use

OBJECTIVE: To describe the waste produced by and environmental implications of individual cigarette consumption (filter tips, packages, and cartons) and tobacco manufacturing. STUDY SELECTION: All available articles and reports published since 1970 related to cigarette consumption and production waste were reviewed. DATA SOURCES: Global cigarette consumption data were used to estimate cigarette butt and packaging waste quantities. Data from the Center for Marine Conservation's International Coastal Cleanup Project were used to describe some environmental impacts of tobacco-related trash. Data from the United States Environmental Protection Agency's (EPA's) Toxics Release Inventory and reported global cigarette consumption totals were used to estimate waste production from cigarette manufacturing. DATA EXTRACTION AND SYNTHESIS: In 1995, an estimated 5.535 trillion cigarettes (27,675 million cartons and 276,753 million packages) were sold by the tobacco industry globally. Some of the wastes from these products were properly deposited, but a large amount of tobacco consumption waste ends up in the environment. Some is recovered during environmental clean-up days. For the past eight years (1990-1997), cigarette butts have been the leading item found during the International Coastal Cleanup Project; they accounted for 19.1% of all items collected in 1997. The tobacco manufacturing process produces liquid, solid, and airborne waste. Among those wastes, some materials, including nicotine, are designated by the EPA as Toxics Release Inventory (TRI) chemicals. These are possible environmental health hazards. In 1995, the global tobacco industry produced an estimated 2262 million kilograms of manufacturing waste and 209 million kilograms of chemical waste. In addition, total nicotine waste produced in the manufacture of reduced nicotine cigarettes was estimated at 300 million kilograms. CONCLUSIONS: Laws against littering relative to cigarette butts could be better enforced. Additional taxes might be levied on cigarette products that would then be directed to environmental clean-up efforts. The tobacco industry should improve the biodegradability of filters, reduce packaging waste, and educate its customers. Worksites and public buildings should be encouraged or required to supply appropriate disposal mechanisms at all building entrances. Public awareness campaigns about the magnitude and prevention of cigarette consumption waste could be developed through partnerships among environmental groups, health organisations, and environmental protection agencies. Tobacco production waste should be a source of concern and regulation by governments throughout the world; it contains numerous chemicals which may be considered health hazards, not the least of which is nicotine produced in the manufacture of low-nicotine cigarettes.     

Comparative analysis of acid resistance in Listeria monocytogenes and Salmonella enterica strains before and after exposure to poultry decontaminants. Role of the glutamate decarboxylase (GAD) system

Data on the ability of chemical poultry decontaminants to induce an acid stress response in pathogenic bacteria are lacking. This study was undertaken in order to compare the survival rates in acid broths of Listeria monocytogenes and Salmonella enterica strains, both exposed to and not exposed to decontaminants. The contribution of the glutamate decarboxylase (GAD) acid resistance system to the survival of bacteria in acid media was also examined. Four strains (L. monocytogenes serovar 1/2, L. monocytogenes serovar 4b, S. enterica serotype Typhymurium and S. enterica serotype Enteritidis) were tested before (control) and after exposure to trisodium phosphate, acidified sodium chlorite, citric acid, chlorine dioxide and peroxyacids (strains were repeatedly passed through media containing increasing concentrations of a compound). Stationary-phase cells (10⁸ cfu/ml) were inoculated into tryptic soy broth (TSB) acidified with citric acid (pH 2.7 and 5.0) with or without glutamate (10 mM) added, and incubated at 37 °C for 15 min. Survival percentages (calculated from viable colonies) varied from 2.47 ± 0.67% to 91.93 ± 5.83%. L. monocytogenes cells previously exposed to acid decontaminants (citric acid and peroxyacids) showed, when placed in acid TSB, a higher (P < 0.05) percentage of survival (average 38.80 ± 30.52%) than control and pre-exposed to non-acidic decontaminants strains (22.82 ± 23.80%). Similar (P > 0.05) survival percentages were observed in previously exposed to different decontaminants and control Salmonella strains. The GAD acid resistance system did not apparently play any role in the survival of L. monocytogenes or S. enterica at a low pH. This study demonstrates for the first time that prior exposure to acidic poultry decontaminants increases the percentage of survival of L. monocytogenes exposed to severe acid stress. These results have important implications for the meat industry when considering which decontaminant treatment to adopt.     

The contribution of direct energy use for livestock breeding to the greenhouse gases emissions of Cyprus

This paper presents a methodology for the estimation of the contribution of direct energy use to the greenhouse gases emissions of cattle, pig and poultry breeding in Cyprus. The energy consumption was estimated using the factors of 2034 MJ/cow, 2182 MJ/sow and 0.002797 MJ/bird. The greenhouse gases emissions for each animal species and energy source were estimated using emission factor of each greenhouse gas according to fuel type as proposed by the IPCC 2006 guidelines and for electricity according to national verified data from the Electricity Authority of Cyprus. Livestock breeding in Cyprus consumes electricity, diesel oil and LPG. The results obtained, show that the emissions from energy use in livestock breeding contribute 16% to the total agricultural energy emissions. Agricultural energy emissions contribute 0.7% to the total energy greenhouse gases (GHG) emissions. The three species of animal considered contribute 3% to their total livestock breeding emissions when compared with enteric fermentation and manure management, of which 2.6% is CO₂. These results agree with the findings in available literature. The contribution of direct energy use in the greenhouse gases emissions of livestock breeding could be further examined with the influence of anaerobic digestion to the emissions.     

膨润土/沸石制备猫砂实验研究

本文利用X射线(衍)射、SEM及化学分析等方法,研究了北票膨润土及沸石特性.通过实验研究,找出了沸石改性较好的试验条件,确定了膨润土与沸石的最佳配比,制备的猫砂产品比国内猫砂性能好,接近国外进口猫砂的性能指标.     

Effects of newborn characteristics and length of colostrum feeding period on passive immune transfer in goat kids

Majorera goat kids (n = 200) were used to evaluate the effects of litter size, birth body weight, sex, and suckling duration on serum IgG concentrations. Kids were assigned to 1 of 3 experimental groups: litter size and sex were equally distributed in each group. In the first group, kids (n = 67) stayed with their dams for 24 h; in the second group, kids (n = 66) stayed with their dams for 48 h; and in the third group, kids (n = 67) stayed with their dams for 120 h. Blood samples were obtained every 24 h for 5 d, and serum IgG concentration was measured using radial immunodiffusion. In litter sizes of 1 to 2 kids, IgG blood serum concentration was significantly higher (18.30 ± 5.40 mg/mL) than in litters of 3 kids (9.85 ± 4.23 mg/mL). Kid sex did not affect IgG blood serum concentrations. Suckling duration did not affect kid serum IgG concentrations. In conclusion, kids with low birth body weight (<2.8 kg) or from litters of 3 may need special attention. If newborn goat kids are allowed to suckle colostrum for at least 24 h from their dams, this seems to be sufficient time to ingest enough IgG from colostrum to achieve an adequate serum IgG concentration and passive immune protection to avoid failure of passive immune transfer.     

Effect of co-combustion of chicken litter and coal on emissions in a laboratory-scale fluidized bed combustor

Co-combustion of chicken litter (CL) with coal was performed in a laboratory-scale fluidized bed combustor to investigate the effect of CL combustion on pollutant emissions. The emissions of major gaseous pollutants including CO, SO₂, H₂S and NO and temperature distribution along the combustor were measured during the tests. Effects of CL fraction and secondary air on combustion characteristics were studied. The experimental results show that CL introduction increases CO emissions and reduces the levels of SO₂. The ratio of H₂S/SO₂ increases with increasing fraction of CL. NO emissions either increase or decrease depending on the percentage of CL in the mixed fuels. The temperature in the freeboard region increases with increasing the fraction of CL while the reverse is true for the bed temperature.     

Tracing Campylobacter jejuni strains along the poultry meat production chain from farm to retail by pulsed-field gel electrophoresis, and the antimicrobial resistance of isolates

In this study Campylobacter jejuni isolates were recovered from birds, carcasses and carcass portions from two broiler chicken flocks and from equipment used for carcass and meat processing along the production chain from farms to retail stores. Isolates were subjected to pulsed-field gel electrophoresis (PFGE) using SmaI and KpnI restriction enzymes and their antimicrobial susceptibilities were determined. C. jejuni was recovered from product and equipment used with both flocks at each point in the production chain. The prevalence of C. jejuni in poultry products at retail stores was 58.97% (flock 1) and 69.23% (flock 2). SmaI divided 122 C. jejuni strains from flock 1 and 106 from flock 2 into 17 and 13 PFGE types, respectively. PFGE types H and F were present at all steps along the chain, from farms to retail products. Similarly, for both flocks PFGE type D was detected in crates, slaughterhouse and retail stores. Moreover, the PFGE types were highly diverse at the processing and retail steps. Most PFGE types were resistant to ciprofloxacin (95.45%) and tetracycline (81.82%); and multidrug resistant PFGE types were found in the final products. Our study showed that there were several points of cross-contamination of product along the chain, and a high diversity of PFGE types with antimicrobial resistance to ciprofloxacin and tetracycline in the retail products.     

2002年北京市市售鲜鸡蛋和生鸡肉的沙门菌污染情况调查

为了了解北京市市售鲜鸡蛋、生鸡肉的沙门菌污染情况,并为建立食物污染及中毒的预警系统提供数据基础,2002年7、8和9月从北京市四个区的集贸市场、超市、商场和街边小商店共采集鲜鸡蛋100件,生鸡肉100件,进行了沙门菌的定性、定量检测及血清分型。结果表明鲜鸡蛋蛋液中未检出沙门菌,生鸡肉的沙门菌阳性检出率为30%,沙门菌在生鸡肉中的污染情况与销售温度有关。因此,控制沙门菌的污染来源和生鸡肉销售的温度条件是控制沙门菌污染的手段之一。然而,还需要进一步研究的是鲜鸡蛋外源性污染情况的调查;销售温度与污染情况之间相关性的进一步证实。