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151.
European Journal of Forest Research - A correction to this paper has been published: https://doi.org/10.1007/s10342-021-01385-w  相似文献   
152.
A study was conducted with the objective to characterize the morphology of Pelibuey sheep in the state of Colima, Mexico. A total of 386 sheep were scored for 12 body measurements in addition to live weight and five racial and eight functional indices were calculated. The influence of sex on the body measurements and indices was analyzed, and morphological harmony was determined through Pearson correlation. The sexual dimorphism was 1.21, with males being 67 % heavier than females. Females and males had a high and moderate degree of harmony in their morphological model, respectively. Pelibuey sheep were dolichocephalous, tended to be medium- to large-sized according to the thoracic index, with a convex curve rump; they were a homogeneous breed, well adapted to environmental and production conditions of the state of Colima, Mexico, and show an undefined zootechnical aptitude and therefore a great potential to be oriented towards meat or milk production through genetic selection or terminal crossbreeding systems using specialized breeds.  相似文献   
153.
Summary

Plasmid DNA (pARS108) containing the non-destructive selectable marker Green Fluorescent Protein (GFP) gene, and a plasmid containing a cDNA of the Xa21 gene from rice (pXa21-mtaq) were co-transformed into ‘Hamlin’ orange protoplasts using polyethylene glycol (PEG). Alternatively, plasmid DNA (pAO3), containing both genes (GFP and Xa21) was directly transformed into ‘Hamlin’ orange protoplasts. Over 1,000 transgenic plantlets were regenerated from approx. 80 independent transformation events. The transgenic plants showed normal growth and stable GFP expression over more than 2 years in the greenhouse. This is the first report of a large population of transgenic ‘Hamlin’ sweet orange plants containing one or more target gene(s), using a protoplast-GFP transformation system. Polymerase chain reaction (PCR) revealed the presence of the Xa21 cDNA and the GFP genes in all single plasmid transformed plants, and in 35% of the co-transformed plants. Southern blot analysis showed the integration of the cDNA into one-to-five different sites per plant.Western blot analysis showed the accumulation of the rice XA21 protein in the transgenic sweet orange plants. This is the first time that a gene from rice has been stably integrated and expressed in sweet orange plants. Using the protoplast-GFP transformation system, it is possible to avoid the use of Agrobacterium, antibiotic resistance genes, and destructive assay systems.  相似文献   
154.
The examination of 216 donkeys presented for treatment at the Donkey Sanctuary–World Horse Welfare–Universidad Nacional Autonoma de Mexico mobile clinics revealed a number of health and welfare problems. A general overview of the donkeys’ health was made and showed that the median body condition score (BCS) in this population was 2.5. Underweight animals only accounted for 26% of the population. Females, 0–5-year-olds and >21-year-olds, were more likely to be underweight. When analysed, there was no correlation between faecal worm egg count (FEC) and BCS. The prevalence of strongyle infection as assessed by FEC was shown to be 80% with a median FEC of 600 eggs per gramme. Donkeys were assessed for body lesions and showed a high prevalence (71%), particularly in the facial region (54%). Analysis showed that mature animals (6–15 years old) were at increased risk of body lesions compared to older animals (16+ years old) as were donkeys with dental disease and those in particular villages. Risk factor analysis for lesions of the face showed that stallions and geldings are at increased risk as were donkeys wearing halters made from nylon rope. This study has identified areas for further investigation and potential areas where targeted interventions may be made to improve the health and welfare of working donkeys in Mexico.  相似文献   
155.
Abstract

The recent advances in information technology (IT) have had profound impacts on all walks of life and aquaculture is no exception. The growing importance of aquaculture as an alternative source of protein has further emphasized the need to adapt and develop advanced IT for the better management of aquaculture facilities as well as the regional planning for aquaculture development.

It is the objective of this paper to review the use and potential prospects of IT in aquaculture management. The information technologies considered are instrumentation and process control, data management, computerized models, decision support systems, artificial intelligence and expert systems, image processing and pattern recognition, geographical information systems, and information centres and networks. The review includes a brief introduction of each of the aforementioned technologies, followed by a survey of their current application as well as their potential use in aquaculture management.  相似文献   
156.
2012年4、7、9和11月中旬分别对艾比湖流域平原区的灌木林、盐碱地、草地、胡杨林、枸杞园、防护林及农田7种生境下中小型土壤动物群落多样性进行了取样调查.结果表明:获得中小型土壤动物共18971只,隶属于3门12纲29目(30类).不同生境中小型土壤动物群落多样性指标之间差异显著(p<0.05),其中:Shannon-Wiener多样性指数(H)依次为胡杨林>草地>盐碱地>农田>枸杞园>灌木林>防护林;Margalef(M)丰富度指数依次为防护林>胡杨林>枸杞园>农田>草地>灌木林>盐碱地;Simpson优势度指数(C)依次为防护林>灌木林>草地>农田>枸杞园>胡杨林>盐碱地.不同生境中小型土壤动物群落的Jaccard相似性主要为中等相似(处于0.50 ~0.75).群落欧氏聚类和MDS排序分析结果表现为以灌木林、盐碱地及胡杨林为一组的自然荒漠环境类型、以农田和枸杞园为一组的耕作干扰环境类型、草地环境类型和防护林环境类型.研究结果表明,微环境植被类型、土壤环境条件和人为干扰差异是影响该流域中小型土壤动物群落多样性和相似性变化的主要因素.  相似文献   
157.
158.
The effects of supplemental yeast culture, litter size, stage and number of lactation on milk composition were studied in Pelibuey ewes. Twenty ewes were randomly assigned to one of two dietary treatments. Ten control ewes grazed on guinea grass (Panicum maximum) and were supplemented with concentrate. A further ten ewes received the same diet with 14 g/head/day of yeast culture (Saccharomyces cerevisiae). Colostrum was collected within 24 h after parturition, and subsequently, milk samples were collected at fortnightly intervals (7, 21, 35, and 49 days). Total solids content averaged 32% in colostrum and 12.5% in milk. Colostrum of primiparous ewes had higher total solids content than that of ewes with more than five lactations. However, ewes with more than five lactations produced milk with higher net energy, total solids, protein, and casein than ewes with fewer lactations. Milk at 7 days had a significantly higher content of energy, total solids, and fat than milk at 21, 35, and 49 days. Total solids content was lower for ewes rearing one lamb than larger litter sizes. Supplementation with yeast culture did not affect the composition of colostrum and milk, which was mainly affected by the stage and number of lactation.  相似文献   
159.
新疆大学农场资源土壤动物调查初报   总被引:7,自引:0,他引:7  
对新疆大学农场资源土壤动物现状进行了首次调查研究,共获标本2050只,隶属于6门,17纲,26目和56种。根据其经济用途分为食用土壤动物、药用土壤动物、饲料土壤动物、天敌土壤动物、环境指示土壤动物和观赏土壤动物6大类,并论述了资源土壤动物的开发利用和保护措施。  相似文献   
160.
Semiarid rangelands of central Argentina are shaped by fire and grazing. The aim of this study was to quantify the effect of controlled fire on aboveground biomass production of (1) herbaceous species as a whole group and (2) herbaceous species subclassified as desirable or undesirable perennial grasses and as herbaceous forbs at the end of two growing seasons after an experimental fire in a semiarid rangeland of central Argentina. The effect of the length of the resting period after fire on aboveground biomass production of desirable perennial grass species was also assessed; treatments consisted in defoliations at the end of the first and second postfire growing seasons, at the beginning and at the end of the second postfire growing season and only at the end of the second postfire growing season. Total biomass production of the burned treatments was higher than that of the control treatment, the difference being attributed to an increase in desirable perennial grass species biomass. This in turn was negatively affected by defoliation at the end of the first postfire growing season, suggesting that the beneficial effect of fire on biomass production might have been overridden by the stress imposed by an early defoliation. Overall, the results of the present study suggest that grazing should be held back for at least a whole year after the fire to achieve the pursued aim of increasing forage production by the use of controlled fire.  相似文献   
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