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1.
The use of the AFLP (amplified fragment length polymorphism) technique for the characterization of highly inbred Iberian pig breed genotypes and the detection of strain-specific polymorphisms is demonstrated. Twelve different primer combinations were used on individual DNA samples from animals belonging to two black hairless Iberian pig strains, Guadyerbas and Coronado. These amplification reactions allowed the detection of more than 1700 amplification products of which 26 were identified as strain-specific markers, present in all individuals of one strain and absent in the other. Comparison of male and female amplification products within one strain also allowed the identification of 8 male-specific amplified bands. AFLP showed a great power of marker detection due to a high multiplex ratio and high reproducibility. Comparison of similarity and co-ancestry coefficient matrices also showed the usefulness of AFLP markers to estimate genetic relationships between individuals pigs. 相似文献
2.
Miguel Toro Carmen Barragán Cristina Óvilo Jaime Rodrigañez Carmen Rodriguez Luis Silió 《Conservation Genetics》2002,3(3):309-320
Genetic markers provide a useful tool toestimate pairwise coancestry betweenindividuals in the absence of a known pedigree. Inthe present work 62 pigs from two relatedstrains of Iberian breed, Guadyerbas andTorbiscal, belonging to a conservationprogramme with completely known pedigrees since1945, have been genotyped for 49microsatellites. Four coefficients thatsummarise molecular resemblance betweenindividuals together with eightestimators of coancestry have been calculatedfrom this information. Their values werecompared with the genealogical coancestry,calculated from the complete or partialpedigree. The eight estimations obtained usingmolecular information substantiallyunderestimate the coancestry calculated usingthe genealogical analysis. The correlationbetween the estimates and the genealogicalvalues was also calculated. This correlationwas high, between 0.78 and 0.93 for differentestimators, when all pairwise comparisons amongthe 62 animals were considered. However, thecorrelation decreases remarkably to 0.49–0.69and 0.37–0.47 for the Guadyerbas and Torbiscalpopulations respectively, when they wereanalysed separately. All the correlations weresimilar to those obtained when using simplecoefficients of molecular resemblance such asmolecular coancestry or similarity indexes.Finally, simulations were carried out tofurther explore the results obtained. It isconcluded that lack of information on theallele frequencies in the base population mayexplain the bias of these estimators inpopulations with complex pedigrees. 相似文献
3.
In most parts of China, water resources development and utilization has reached or exceeded the international warning level, especially in the northern arid and semi-arid regions, the serious water stress have aroused worldwide concerns. Many issues of water resources are closely and some inseparably associated with human activities. In this study, the water footprint (WF) and related indicators were applied as comprehensive indicators to assess real water use by humans from the consumption perspective. A Fuzzy Comprehensive Evaluation Model (FCE) was used for the evaluation in its role to assess water stress. And the index system of water stress assessment including four aspects, namely water supply and demand balance, socio-economy, agricultural production and ecological environment was established. Taking the case of Hebei province of China where there is serious conflict between water supply and demand, water stress assessment of all eleven administrative areas for the period 2000–2013 was analyzed. The findings showed that water stress was denoted by three levels, namely high water stress (red zone), general water stress (yellow zone) and low water stress (blue zone), which lays the foundation of the further research on water risk warning. According to the results of water stress assessment and the socio-economic development trends of Hebei, a Markov Chain Risk Warning model was built to describe the risk state of water system and to predict the transition probability of future states. This was intended to focus on the possibility that water stress levels might change into higher water stress level. The current study aims at extending earlier research by making a first step from water footprint estimation towards water stress assessment and providing reference for scientific management of water resources in arid and semi-arid regions. 相似文献
4.
Life-cycle analysis on biodiesel production from microalgae: Water footprint and nutrients balance 总被引:5,自引:0,他引:5
Jia YangMing Xu Xuezhi ZhangQiang Hu Milton SommerfeldYongsheng Chen 《Bioresource technology》2011,102(1):159-165
This research examines the life-cycle water and nutrients usage of microalgae-based biodiesel production. The influence of water types, operation with and without recycling, algal species, geographic distributions are analyzed. The results confirm the competitiveness of microalgae-based biofuels and highlight the necessity of recycling harvested water and using sea/wastewater as water source. To generate 1 kg biodiesel, 3726 kg water, 0.33 kg nitrogen, and 0.71 kg phosphate are required if freshwater used without recycling. Recycling harvest water reduces the water and nutrients usage by 84% and 55%. Using sea/wastewater decreases 90% water requirement and eliminates the need of all the nutrients except phosphate. The variation in microalgae species and geographic distribution are analyzed to reflect microalgae biofuel development in the US. The impacts of current federal and state renewable energy programs are also discussed to suggest suitable microalgae biofuel implementation pathways and identify potential bottlenecks. 相似文献
5.
Carbon footprint (CFP) is widely applied as an indicator when assessing environmental sustainability of products and services. The objective of the present study is to evaluate the validity of CFP as overall environmental indicator for representing the environmental burden of residents from urbanized areas. Applying four different Life Cycle Impact Assessment (LCIA) methods environmental impact profiles were determined for the consumption patterns of 1281 Danish urban residents. Six main consumption components were distinguished including road transport, air travel, food, accommodation (covering consumption of materials for the construction of dwellings) and use of energy in terms of thermal energy, and electricity. The results for the individual consumption components showed a strong correlation between CFP and nearly all other impact indicators for all the applied LCIA methods However, upon aggregation of the indicator results across consumption components, the impact indicators for the total consumption showed no significant correlation between CFP and the other impact scores for any of the four impact assessment methods. These findings suggest that while CFP can be a good indicator of the environmental burden associated with specific activities, this is not the case for more complex activities (such as consumption patterns related to urban life styles). This conclusion discourages the use of CFP as sustainability measure in relation to regulation of private or public consumption. 相似文献
6.
The water footprint (WF) has been developed within the water resources research community as a volumetric measure of freshwater appropriation. The concept is used to assess water use along supply chains, sustainability of water use within river basins, efficiency of water use, equitability of water allocation and dependency on water in the supply chain. With the purpose of integrating the WF in life cycle assessment of products, LCA scholars have proposed to weight the original volumetric WF by the water scarcity in the catchment where the WF is located, thus obtaining a water-scarcity weighted WF that reflects the potential local environmental impact of water consumption. This paper provides an elaborate critique on this proposal. The main points are: (1) counting litres of water use differently based on the level of local water scarcity obscures the actual debate about water scarcity, which is about allocating water resources to competing uses and depletion at a global scale; (2) the neglect of green water consumption ignores the fact that green water is scarce as well; (3) since water scarcity in a catchment increases with growing overall water consumption in the catchment, multiplication of the consumptive water use of a specific process or activity with water scarcity implies that the resultant weighted WF of a process or activity will be affected by the WFs of other processes or activities, which cannot be the purpose of an environmental performance indicator; (4) the LCA treatment of the WF is inconsistent with how other environmental footprints are defined; and (5) the Water Stress Index, the most cited water scarcity metric in the LCA community, lacks meaningful physical interpretation. It is proposed to incorporate the topic of freshwater scarcity in LCA as a “natural resource depletion” category, considering depletion from a global perspective. Since global freshwater demand is growing while global freshwater availability is limited, it is key to measure the comparative claim of different products on the globe's limited accessible and usable freshwater flows. 相似文献
7.
In a conservation programme with genealogical records it is possible to estimate the amount of variability of the founder population from a measure of the similarity among the individuals in the current population based on microsatellite markers. Here we compare three available methods and we shown that the one based on the molecular coancestry coefficient should be preferred. 相似文献
8.
Sustainability evaluation of mariculture is needed for policy decision-making in its development. Zhao et al. (2013) developed the method of emergy ecological footprint to evaluate an offshore small fish farm in the East China Sea. After re-examination of their method, data analysis process and results, three questions are presented (1) what is the nature of this method? (2) How much impact do the recognition and classification of input flows on the results? (3) Do their evaluated results confirm to the real situation of this farm? Further discussions are also made on several main studies about the emergy ecological footprint method. Our results imply: (1) there is a need to improve this method; (2) the input flows should be carefully processed due to their great impacts on the results; (3) the essential data and comparative analysis are needed to support this evaluation. 相似文献
9.
加工、贮存因素对实验动物颗粒饲料品质的影响 总被引:1,自引:0,他引:1
饲料颗粒化是实验动物饲料标准化的重要内容,是实验动物质量控制的重要环节。影响颗粒饲料质量的因素很多,现就饲料加工、贮存环节中对其品质的影响因素加以分析。1 加工工艺对颗粒饲料品质的影响1.1 原料选择的影响因素 饲料的原料,特别是谷物原料,易被野鼠及昆虫污染,可能传播疾病,尤其是沙门氏杆菌。因此在选择、贮存时要引起注意。某些饲料原料含有营养素拮抗因子,如大豆含胰蛋白酶抑制因子、菜籽饼含芥子甙、芥子硷等多种有毒有害物质,影响饲料的营养品质,选择时应尽量不用或少用,或去毒后再用。某些饲料对实验动物的适口性差,如高梁、棉籽饼 相似文献
10.
11.
The effect of a previously reported PvuII polymorphism in oestrogen receptor 1 (ESR1) was analysed in an F(2) population of Iberian x Meishan pigs. We tested three hypotheses: (1) that a causal mutation was fixed in the parental populations, (2) that a causal mutation existed that was in complete linkage disequilibrium with the alleles of the PvuII polymorphism and (3) that a causal mutation existed in linkage disequilibrium within each parental population. The third model was the most plausible based on the available data. ESR1 alleles displayed different patterns of linkage disequilibrium with the causal mutation in each of the parental populations and the PvuII polymorphism was clearly not the causal mutation. As a consequence, the use of the ESR1 mutation for selection must be evaluated for a particular pig population before it is applied. 相似文献
12.
Mapping of the porcine oestrogen receptor 2 gene and association study with litter size in Iberian pigs 总被引:2,自引:0,他引:2
Genes encoding the oestrogen receptors (ESR) are considered candidate genes for prolificacy traits due to the key role these molecules play in the regulation of reproductive physiology. In this paper, we report the assignment of the pig ESR2 gene to porcine chromosome 1 by radiation hybrid mapping. Most of the ESR2 cDNA was sequenced from Iberian pig ovarian RNA samples and one A/G single nucleotide polymorphism (SNP) was found at exon 5, being associated with a Met/Val substitution at position 949. This SNP was genotyped using a PCR-RFLP (Hsp92II) protocol and its potential effect on litter size was evaluated in two Iberian pig populations. However, no statistically significant association between the ESR2 polymorphism and litter size was found. 相似文献
13.
《Archives of animal nutrition》2013,67(4):227-236
Abstract A group of 11 pigs was fed with 70 g feed per kg of metabolic weight (H pigs) and another group of 11 pigs was fed with 50 g feed per kg of metabolic weight (L pigs). In both experimental groups (H and L pigs), it was observed that the higher initial proportion of C16:0, C18:0 and C18:2 (n-6) in backfat at the beginning of the free-range feeding period, the greater decrease rate of these fatty acid proportions regarding weight gain during the free-range fattening period took place. On the other hand, the greater initial proportion of C18:1 (n-9), the smaller increase rate in the concentration of this fatty acid was observed. The intramuscular neutral lipids from L pigs had higher C18:3 (n-3) and lower proportions of monounsaturated fatty acids (MUFA) than those from H pigs, while intramuscular polar lipids from L pigs had significantly higher proportions of C18:0, PUFA, C18:3 (n-3) and (n-3) and significantly lower MUFA and C18:1 (n-9) proportions than those from H pigs. The α-tocopherol concentration found in Longissimus dorsi from L pigs was significantly higher (p < 0.012) than those from H pigs. 相似文献
14.
Quantifying electricity generation and waste transformations in a low-cost, plug-flow anaerobic digestion system 总被引:1,自引:0,他引:1
Stephanie Lansing Joaquín Víquez Helen Martínez Raúl Botero Jay Martin 《Ecological Engineering》2008,34(4):332
Methane production, electricity production, and wastewater transformations were quantified for a digestion system that combines biogas from a swine digester and dairy digester in Costa Rica. The low-cost, plug-flow digesters were not heated and were operated in the lower portion of the mesophilic range (25–27 °C).The dairy digester produced 27.5 m3/day of biogas with 62.6% methane and reduced organic matter (COD) by 86%. The swine digester produced 6.0 m3/day of biogas with 76.4% methane and reduced COD by 92%. Combining biogas from a swine and dairy digester, increased electricity production due to the higher biogas production rate of the dairy farm and the higher quality biogas obtained from the swine farm. The farm’s 2-h peak electricity demand (12.9 kW/day) was 81.8% met. The electricity was produced using manure equivalent to the quantity excreted by 5 dairy cows and 40 pigs remaining in corrals 100% of the time.The $21,000 capital cost of the digester project will be recovered in 10.1 years through electricity savings and reductions in wastewater fines. If the generator were more appropriately sized for the farm, the capital recovery time would have been 7.6 years. 相似文献
15.
The need for the extensive use of sustainability assessment as a standalone tool to evaluate the environmental, economic and social aspects of an activity be it at project, product, company or region level has resulted in the development of various methods and standards. There are several indicator issues to address each aspect of sustainability and it is not easy for decision makers to understand the result due to the use of multiple indicators. In this regard, the paper aims at the identification and combination of indicators allowing to assess the sustainability which is applicable to a carbon fiber recycling sector. Indicators selection were carried out by performing an extensive literature review on existing publications dealing with the different pillars of sustainability and setting a number of selection criteria to prioritize indicators that are relevant to the sector. For the environmental aspect global warming, acidification and human toxicity seem to be the most relevant. The social-economic aspect can be addressed through considering the resource impact assessment by considering the supply risk due to the geological scarcity of a resource and the potential supply disruption due to geopolitical and other social factors. The finding shows that three indicators have been identified enabling the assessment of the environmental pillar. Then the necessity to use extra resources indicators was shown and justified by the need of providing a shorter timeframe perspective as well as to consider the amount of fiber to be recycled in the future and also to determine the potential benefit provided by the creation of this sector to the resource strategy point of view. This will be made possible by using such method as the criticality assessment that enable the consideration of geological and geopolitical supply risk as well as the characterization of the system dependence to a specific resource.Finally, these results lead to the expression of the need to the development of a novel indicator assessing the criticality of carbon fibers as well as the expression of the necessity for further research on the socio-economic perspectives. 相似文献
16.
Esteve-Codina A Kofler R Himmelbauer H Ferretti L Vivancos AP Groenen MA Folch JM Rodríguez MC Pérez-Enciso M 《Heredity》2011,107(3):256-264
Despite dramatic reduction in sequencing costs with the advent of next generation sequencing technologies, obtaining a complete mammalian genome sequence at sufficient depth is still costly. An alternative is partial sequencing. Here, we have sequenced a reduced representation library of an Iberian sow from the Guadyerbas strain, a highly inbred strain that has been used in numerous QTL studies because of its extreme phenotypic characteristics. Using the Illumina Genome Analyzer II (San Diego, CA, USA), we resequenced ~ 1% of the genome with average 4 × depth, identifying 68,778 polymorphisms. Of these, 55,457 were putative fixed differences with respect to the assembly, based on the genome of a Duroc pig, and 13,321 were heterozygous positions within Guadyerbas. Despite being highly inbred, the estimate of heterozygosity within Guadyerbas was ~ 0.78 kb(-1) in autosomes, after correcting for low depth. Nucleotide variability was consistently higher at the telomeric regions than on the rest of the chromosome, likely a result of increased recombination rates. Further, variability was 50% lower in the X-chromosome than in autosomes, which may be explained by a recent bottleneck or by selection. We divided the whole genome in 500 kb windows and we analyzed overrepresented gene ontology terms in regions of low and high variability. Multi organism process, pigmentation and cell killing were overrepresented in high variability regions and metabolic process ontology, within low variability regions. Further, a genome wide Hudson-Kreitman-Aguadé test was carried out per window; overall, variability was in agreement with neutral expectations. 相似文献
17.
《Animal : an international journal of animal bioscience》2019,13(12):2765-2772
The Iberian pig is one of the pig breeds that has the highest meat quality. Traditionally, producers have bred one of the available varieties, exclusively, and have not used crosses between them, which has contrasted sharply with other populations of commercial pigs for which crossbreeding has been a standard procedure. The objective of this study was to perform an experiment under full diallel design among three contemporary commercial varieties of Iberian pig and estimate the additive genetic variation and the crossbreeding effects (direct, maternal and heterosis) for prolificacy. The data set comprised 18 193 records for total number born and number born alive from 3800 sows of three varieties of the Iberian breed (Retinto, Torbiscal and Entrepelado) and their reciprocal crosses (Retinto × Torbiscal, Torbiscal × Retinto, Retinto × Entrepelado, Entrepelado × Retinto, Torbiscal × Entrepelado and Entrepelado × Torbiscal), and a pedigree of 4609 individuals. The analysis was based on a multiple population repeatability model, and we developed a model comparison test that indicated the presence of direct line, maternal and heterosis effects. The results indicated the superiorities of the direct line effect of the Retinto and the maternal effect of the Entrepelado populations. All of the potential crosses produced significant heterosis, and additive genetic variation was higher in the Entrepelado than it was in the other two populations. The recommended cross for the highest yield in prolificacy is a Retinto father and an Entrepelado mother to generate a hybrid commercial sow. 相似文献
18.
This study was initiated to understand whether feeding behaviour and physiology may contribute to the rate of fatigued pigs at processing plants. Specifically, this study sought to determine: (1) how often pigs eat during the day, (2) the times of the day they eat and (3) a first approximation of the time from feed consumption to excretion (rate of passage) when housed in a group in conventional finishing facilities. Finally, models were constructed to try to predict the percentage of pigs with empty/diminished gastrointestinal (GI) tracts depending on the time of day of truck loading and transport durations. Pigs were randomly selected, weighed and selected for behavioural observations. From video records and live observations, the number of meals (feeding bouts) per day and the time of the day meals took place were recorded. Feed containing chromic oxide was fed to determine when a given meal was excreted. With the feeding times of day determined, models were constructed of the percentage of pigs that would have empty stomachs depending on the time of day pigs were removed from the barn and the length of transport/lairage. Finishing pigs housed in groups ate 5.6 ± 0.6 meals per day with an average feeding bout (meal) length of 11.3 ± 1.1 min. Many pigs fed ad libitum ate most of their meals during the afternoon and evening. The rate of passage of feed was 20.5 h (range = 18 to 24 h). Because fewer pigs ate in the late evening through morning, if pigs were shipped at these times they would have an increased risk of arriving at the stun at a plant with an empty GI tract. Some of the variation in rates of fatigued pigs and pork quality may be explained by times of day taken off feed and transport duration. Shipping in the afternoon or early evening may result in fewer pigs with empty/diminished GI tracts at processing which may influence the rate of fatigued pigs and pork quality. 相似文献
19.
《Animal : an international journal of animal bioscience》2014,8(10):1569-1576
An experiment of a 2×2 full diallelic cross between two contemporary Iberian pig strains (Retinto: RR, and Torbiscal: TT) was conducted to estimate the crossbreeding effects for growth and carcass traits. Phenotypic records were obtained under intensive management and consisted of two different data sets. The first set comprised growth traits until weaning and was collected at two different farms (6236 and 1208 records, respectively). Specific data included individual piglet weight at birth and at weaning at 28 days and average daily gain from birth to weaning at 28 days (ADG28) for both RR and TT and their reciprocal crosses. The second set comprised growth data from birth to slaughter (~340 days and ~160 kg) and carcass traits from 349 individuals (randomly) sampled at weaning from the first dataset. Data were analyzed through a Bayesian analysis by using a reparameterization of Dickerson’s model that allowed estimation of the posterior distributions of the following crossbreeding effects: average maternal breed effect (gM), average paternal breed effect (gP) and individual heterosis (hI). Results showed that the relative magnitude of crossbreeding effects depends on the trait analyzed. Crosses where Torbiscal strain was used as mother (RT and TT) achieved the greatest performance for all growth traits at weaning, leading to remarkable gM effects. The most outstanding example is the case of ADG28 where the probability of relevance was one. In contrast, TR cross showed the greatest differences from RR cross for all growth at slaughter and carcass traits. These differences were mainly due to hI and gP crossbreeding parameters. In particular, the posterior mean of hI was more noticeable for live weight at slaughter, average daily gain at slaughter and carcass length, while gP was more relevant for hams (kg) and loins (kg) representing from 3% to10% of average performance of traits. Hence, growth traits at weaning did not reveal any notable advantage of the crossbreeding scheme because of the superiority of the Torbiscal strain with respect to its mothering ability and the small hI. However, results from growth and carcass traits at slaughter would support the implementation of a TR crossbred system. It would allow exploitation of both the gP of the Torbiscal strain and the hI between these two Iberian pig strains. Additionally, gP estimates and phenotypic differences between reciprocal crosses might suggest signs of the presence of paternal genetic imprinting in primal cuts traits. 相似文献