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Growth performance of Woyto-Guji and Central Highland goat breeds under traditional management system in Ethiopia
2016
Zergaw, N. | Dessie, Tadelle | Kebede, K.
The study was conducted to evaluate the productive and reproductive performance of Central Highland and Woyto-Guji goat breeds in Meta-Robi and Konso districts, respectively. A total of 240 farmers were interviewed using semi-structured questionnaires to describe kidding pattern, kidding interval, weaning age and milk production. On-farm performance traits were recorded on 730 goats of 157 households. In Konso, majority of kidding occurred in May, whereas in Meta-Robi it was in September. There was a difference in the average kidding interval and age at weaning between the breeds. Kids birth weight (2.03 Vs. 2.68kg) and does postpartum weight (26.6 Vs. 28.2kg) were lower in Woyto-Guji goats than in Central Highland goats. Average 90 day kids' weight and average daily weight gain between birth and 90 days were not different among the breeds. Average 180 day weight (15.7 Vs. 11.5kg) and average daily weight gain between 91 and 180 days (65.4 Vs. 31.9 g/day) were better in Central Highland goats than in Woyto-Guji goats.
Afficher plus [+] Moins [-]Genetic diversity of some Ghanaian pigs based on microsatellite markers
2016
Ayizanga, R.A. | Kayang, B.B. | Adomako, K. | Adenyo, C. | Inoue-Murayama, M. | Asamoah, L.
A knowledge of the level of genetic diversity is very important in ensuring the sustainable utilisation of animal genetic resources. To this end, the genetic diversity of some local pigswas assessed by genotyping 86 unrelated pigs in four regions of Ghana namely Northern (Tingoli = 9), Upper West (Papu = 31 and Babile = 32) and Upper East (Gia = 14) using 12 microsatellite markers.The number of alleles (Na), number of effective alleles (Ne), observed heterozygosity (Ho), expected heterozygosity (He) and inbreeding coefficient (FIS) were used to assess the level of genetic differentiation among the five populations in this study. All loci studied were polymorphic and the mean number of alleles ranged from 4.58 (Yorkshire) to 10.58 (Papu) with an overall average of 7.65 alleles. At all the 12 loci studied, inbreeding coefficient (FIS) deviated significantly from zero with a mean of 0.32. When the Nei’s standard genetic distance based on the proportions of shared alleles was used to construct a neighbour joining tree, pigs from the different communities sampled in the Upper West region emerged with the highest bootstrap value of 90%. Generally, the sampled pigs represent distinct populations with a moderate amount (12%) of genetic differentiation but considerable amount of inbreeding (29%) has taken place within these populations over the years. This is the first report of the genetic diversity of Ghanaian local pigs using microsatellite markers.
Afficher plus [+] Moins [-]Long-term influence of large forest fire on ground vegetation
2016
Purina, L., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Straupe, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Liepa, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Libiete, Z., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Zadina, M., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Jansons, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Fire is a major disturbance in hemiboreal forests; it affects not only trees, but also ground vegetation. Previous studies have analysed the succession of ground vegetation after the fire, but not addressed the impact of the size of the burned area on revegetation of it. Therefore, the aim of our study was to assess the differences in post-fire ground vegetation in relation to the distance from the edge of the affected area. Vegetation data were collected using Braun-Blanquet method in three sites (122 sample plots) affected by forest fire and five clearcuts (not affected by fire) (92 plots), all regenerated by Scots pine 6 – 7 years before the assessment. The number of ground vegetation species (in all sites predominantly birds or wind dispersed) as well as their projective cover was not affected by the distance from the nearest edge of burned or clearcut, except in burned sites on dry sand soil (Vaccinosa and Myrtillosa), where herbaceous plant and shrub cover was decreasing (from 23.5% to 11.6%) and bryophyte and lichen cover – increasing (from 3% to 13.9%) with an increasing distance from the edge of the area. The total number of plants in burned areas was twice smaller than in clearcut in the same soil conditions but such large difference in projective cover was not observed. There were no significant differences between burned and clearcut areas in respect to Ellenberg’s indicator values on both soil types, as well as no trend in Ellenberg’s values for soil moisture in relation to distance from the nearest stand edge.
Afficher plus [+] Moins [-]Genetic differences in needle cast damage of Scots pine (Pinus sylvestris L.)
2016
Polmanis, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Klavina, D., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Gaitnieks, T., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Baumanis, I., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Lazdins, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
The impact of climatic and genetic factors on needle cast damage, as well as relationship between the degree of damage and survival and growth of trees was evaluated in the study. The analysis was done in two series of experiments, both established in two locations in Latvia (central and eastern part). Needle cast damage (in 5 grade scale) as well as the height and height increment, diameter of root collar and survival of trees were assessed. Results suggest that the degree of needle cast damage was influenced by the genetic, as well as climatic factors, and also their interaction. The average degree of needle cast damage in experiment of open-pollinated families was 4.7 ± 0.01 in central and 4.6 ± 0.03 in eastern Latvia; in the experiment of control-crossed families it was 4.6 ± 0.02 in central and 3.4 ± 0.04 in eastern Latvia. The impact of genetics on the needle cast damage degree was statistically significant (p is less than 0.05), and this effect was observed when any of growth traits (diameter, height or height increment) was used as a covariate in analysis. Results suggest the potential to select more resistant families, since the genetic correlation of grade of the damage between locations was significant (r = 0.40 - 0.72) and therefore improve also the growth of trees, since the grade of the damage had a negative correlation with growth traits both at provenance and family mean level (r = -0.69 and r = -0.42; p is less than 0.01).
Afficher plus [+] Moins [-]Impact of needle cast damage on sanitary condition in young Pinus sylvestris stands in central Latvia
2016
Polmanis, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Miezite, O., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Baumanis, I., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Lazdins, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Recent studies have demonstrated the occurrence of different needle cast (Lophodermium spp.) species in young Scots pine Pinus sylvestris L. stands in different regions of Latvia. The impact of these fungi has been known also historically, but is predicted to increase in future due to climate changes that are forecasted to have a positive impact on presence and vigour of various species of fungi. The aim of the study was to characterize the needle cast damage in young Scots pine stands in central Latvia. Material was collected in 12 Scots pine stands at the age of 3 to 26 years in 28 plots with a total area of 8.1 ha in the middle of two consecutive growing seasons (years 2012 and 2013). The impact of disease was visually assessed using a 5 grade scale, depending on the proportion of damaged (brown) one-year old needles. Incidence of damaged trees (P, %) and damage intensity (R, %) was calculated and used to characterize the occurrence and severity of the infection in the stands as well as its link to other stand parameters. Damage incidence (ranging from 20 to 100%), as well as the intensity (from 4 to 35%) was slightly (incidence-also significantly) higher in 2013 in comparison to 2012; correlation between those two parameters was strong in both years (r = 0.94 and r = 0.84, respectively). The stand age, density (ranging from 1200 to 6900 trees haE-1) and tree height did not significantly correlate with the damage incidence or intensity. Forest type (Hylocomiosa or Myrtillosa mel.) was not a significant factor, too.
Afficher plus [+] Moins [-]Impact of wood ash and potassium sulphate fertilization on growth of Norway spruce stand on organic soil
2016
Okmanis, M., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Skranda, I., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Lazdins, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Lazdina, D., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Wood based ash can be used as a liming material and fertilizer in forest, thus providing a solution for utilization of wood ash and formation of additional increment of trees, especially on organic soils, where lack of potassium and phosphorus is a well-known factor limiting the growth of trees. Yet, many studies have been made with adverse results mostly because of different soil types and species investigated. However, by now the best results on fertilization with wood ash have been found on drained peatlands, where some nutrient deficiencies have emerged. The aim of this study was to find out the growth response of Norway spruce on drained organic soils after spreading of potassium sulphate (K2SO4) and wood ash (WA). The experiment was carried out in three middle aged Norway spruce (Picea abies) stands on drained mineral and peat soil. Experiment consisted of three replications of each treatment in each stand including WA, K2SO4 and the control on 400 square meter sub-sample plots each. The diameter and height of trees were measured. The samples of increment cores were collected 4 years after fertilization to determine the additional volume increment, which varied from 8.5 m**3 haE-1 in WA plots and from 9.7 m**3 ha-1 to 17.2 m**3 haE-1 on K2SO4 plots. Both - the wood ash and potassium application - significantly increased the increment of Norway spruce on drained mineral and peat soil, although no significant differences were found between the treatments (p = 0.82, α = 0.05).
Afficher plus [+] Moins [-]Sapropel as an adhesive: assessment of essential properties
2016
Obuka, V., University of Latvia, Riga (Latvia) | Veitmans, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Vincevica-Gaile, Z., University of Latvia, Riga (Latvia) | Stankevica, K., University of Latvia, Riga (Latvia) | Klavins, M., University of Latvia, Riga (Latvia)
Recently, a renewed interest in non-harmful, environmentally friendly adhesives has ensued among the industry professionals, both environmental and healthcare scientists. In this study, organic rich lake sediments (sapropel) from two lakes located in Latgale Region of Latvia were used as a glue to investigate the potential use of such adhesive for manufacture of composite materials from wood. Sapropel is a valuable resource with multiple areas of application, e.g., agriculture, balneology. Available amount of sapropel in Latvia is estimated at up to 2 billion m**3. Prior the tests, characterization of sapropel samples was done. Properties of the obtained composite material samples from wood and sapropel, as well as the mechanical properties were investigated. Tests involved the assessment of static bending strength and shear strength tests, durability according to their operating performance (D1-D4), as well as dried natural peat tensile strength perpendicular to the grain direction were determined and compared to the literature data; and the opportunities to use new composite materials in accordance with to the standards were discussed. The results of the study revealed an insight into possibilities to develop products of higher added value from sapropel as adhesive in combination with various resources. Results indicated that the samples made from Lake Pilvelis sapropel gain to better results of bending strength determination (parallel bending - 88.7 MPa). The aim of this study was to explore options to produce veneer using two kinds of sapropel as a glue and to determine the optimal properties according to the standards, as well as to characterize properties of the obtained composite material.
Afficher plus [+] Moins [-]Wood fibre insulation material
2016
Veitmans, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Grinfelds, U., Latvian State Inst. of Wood Chemistry, Riga (Latvia)
As worldwide trends are changing gradually and sustainable resources economy and reduction of hazardous emissions are coming to the forefront, several industry sectors are forced to revalue their resource consumption. The main emphasis is currently placed on the recycling of by-products. One of the methods, definitely, includes burning of by-products to generate power, however it is not always the most efficient one. By-products must be used in the manner that ensures that they provide high added value for the operation of the company and are environmentally friendly. This research focuses on the use of the by-products of birch (Betula) veneer manufacturing, in order to obtain thermal insulation material. The following characteristics of the wood fibre insulation material were determined: thermal conductivity, water absorption, vapour permeability, and prototype reaction to fire. The characteristics of the obtained wood fibre thermal insulation material: thermal conductivity 0.038 W•mE-1•kE-1; water absorption 12 kg•mE-2; the conformity of the material even to D fire reaction class was not determined. The principal conclusion: the wood fibre thermal insulation material conforms to the requirements set for thermal insulation materials.
Afficher plus [+] Moins [-]Dynamics of rural areas development in Poland - convergence analysis
2016
Wojewodzka-Wiewiorska, A., Warsaw Univ. of Life Sciences (Poland) | Dudek, H., Warsaw Univ. of Life Sciences (Poland)
The article deals with the issue of rural development in Poland. The aim of the article is to determine the dynamics of change in the level of socio-economic development of rural communes in Poland (NUTS 5) in the years 2004 – 2014 through verification of the hypothesis of the existence of beta-convergence. The beta-convergence approach is verified by econometric modelling techniques. The statistical data came from the Local Data Bank (LDB) of the Central Statistical Office (CSO). Based on the analysis of changes in the development level of the rural areas in Poland it was stated that there is convergence. However, the strength of the convergence process is different depending on the dimensions of development. It reported a strong relationship between the average growth rate of aggregate indicators relating to the financial dimension. In other dimensions, such as labour market, living conditions, health and social care, education, demography and culture, it showed the occurrence of slow convergence processes.
Afficher plus [+] Moins [-]Comparative analysis of sustainable development of Šiauliai, Telšiai counties and the Republic of Lithuania
2016
Tamosiunas, T., Siauliai Univ. (Lithuania) | Mazajevaite, R., Siauliai Univ. (Lithuania)
The paper analyses sustainable development situation in Šiauliai and Telšiai counties between 2004 and 2013 and compares it with respective situation in the Republic of Lithuania. In order to provide an integrated assessment of the situation, the analysis employed the method of calculating sustainable development indices, close to the Compass method, often applied in research practice all over the world. The calculated indices of economic and social development and environmental state in Šiauliai and Telšiai counties and in Lithuania have shown changes in sustainable development during the period of 10 years. Integrated sustainable development indices, obtained by summing up economic and social development and environmental state indicators demonstrated that sustainable development situation in Šiauliai and Telšiai counties and the Republic of Lithuania between 2004 and 2013 was very similar. Due to the first EU investments between 2005 and 2007, a huge improvement of economic and social situation took place, environmental protection also improved. However, the global economic crisis of 2008 – 2010 decreased the sustainable development of Lithuania and the mentioned counties. In 2011 – 2012, the sustainable development situation started improving again, however, not in such big proportions as in 2005 – 2007. Recession in 2013, in fact, brought the level of sustainable development of Lithuania, Šiauliai and Telšiai counties down to the level of 2004. Conclusions provide generalisation of the research outcomes and possible sustainable development trends for Šiauliai and Telšiai counties.
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