خيارات البحث
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Growth, reproductive performance and survival rate of Bonga sheep and their crossbreds in southern Ethiopia
2020
Abate, Z. | Kirmani, M. | Getachew, T. | Haile, Aynalem
Selection efficiency for growth performance of Menz sheep in a community-based breeding program
2020
Abebe, A. | Banarjee, S. | Goshmie, S. | Bisrat, A. | Besufikad, S. | Zewdie, T. | Gizaw, Solomon
The study was undertaken to evaluate the efficiency of selection on growth performance of Menz sheep under a community-based breeding program (CBBP) from the period of 2009 – 2017. A total of 3996 lamb records (ram lambs 2025/ ewe lambs 1971) were used to evaluate the phenotypic and genetic factors affecting the growth traits of Menz sheep. REML in Wombat and General linear model on SAS (version 9.0) were used to evaluate selection efficiency for growth of Menz sheep. The least squares means and standard errors on phenotypic growth weight for birth, weaning age, six month age and yearling age were 2.58±0.004, 8.99±0.02, 13.28±0.02 and 19.94±0.06 kg, respectively. The effect of sex was significant (p<0.001) only for birth weight and no significance effect (p>0.05) was observed for weaning, six month and yearling weights. All growth traits were not affected by fixed effect of parity and birth type in this particular study. However, birth season and birth year had a great influence (p<0.0001) on all growth traits. The genetic trend on estimated breeding values (EBV) was not consistent across years and varied between sexes. The highest EBV for weaning, six month and yearling were recorded for the year 2013 and the lowest in 2009 (at weaning and six month) and 2015 (at yearling).The female EBV (at weaning, six month and yearling) was higher than male for the current (2017) and base population (2009).The responses to selection as compared to base population (2009) for birth, weaning, six month and yearling weight were – 0.00446Kg, + 0.11Kg, + 0.54Kg and + 0.75Kg respectively. This study indicates that improvement in body weight for Menz sheep through CBBP is possible; however, the response to selection varied across years and its pattern was irregular for the implemented years due to the problem on selection of breeding rams (lower availability of breeding rams) and management effect.
اظهر المزيد [+] اقل [-]Productivity of Abergelle, Central Highland and Woyto-Guji goat breeds in Ethiopia
2020
Jembere, Temesgen | Haile, Aynalem | Dessie, Tadelle | Kebede, Kefelegn | Okeyo Mwai, Ally | Rischkowsky, Barbara A.
Productivity of Abergelle, Central Highland and Woyto-Guji goat breeds in Ethiopia
2020
Jembere, Temesgen | Haile, Aynalem | Dessie, Tadelle | Kebede, Kefelegn | Mwai, Ally Okeyo | Rischkowsky, Barbara
The objective of this paper was to evaluate the productivity of three indigenous goat breeds from Ethiopia namely Abergelle (AB), Central Highland (CH) and Woyto-Guji (WG) based on their kids’ total live weight at three months (LWW), survival rate to three months (S3M) and average daily milk yield (ADM, for AB only). The LWW were standardized by year and post partum weight (ppw) of does. In addition, productivities expressed as the body weight of three months old kids produced per doe per year (index I) and per kg ppw per year (Index II) were also assessed. The overall least squares means of LWW for AB, CH and WG were 7.6, 15.3 and 10.2 kg, respectively. The overall mean of the ADM for AB was 367.10±139.79 ml. The S3M was 76.30%, 78.50% and 77.70%, for AB, CH and WG, respectively. Overall means of index I and index II were 14.7 kg and 0.50, respectively. Year of birth affected (p<0.05) LWW and S3M of AB, CH and WG as well as the indices. The ADM and S3M of AB and LWW of WG were also influenced ( p<0.001) by village of kidding. The LWW and S3M of the three breeds were not influenced (p>0.05) by sex of lambs. On the other hand parity of birth had clear influence (p<0.05) on ADM and S3M of AB and index I. Season of birth also had influence (p <0.001) on LWW of AB only. The CH does produce about 200% LWW of AB does and about 150% LWW of WG does. The CH was found to be the most productive breed in terms of all assessed parameters followed by WG. The AB was best suited for dual services (meat and milk). Hence, goat meat investment priorities in Ethiopia could target Central Highland goats. However, the productivity of these goat breeds should be improved in their respective localities by minimizing possible factors hampering their productivity
اظهر المزيد [+] اقل [-]Evaluation and characterization of semen quality in rams of Menz, Dorper and Awassi crosses in different seasons in Ethiopia
2020
Goshme, Shenkute | Banerjee, S. | Rekik, Mourad | Haile, Aynalem | Yitagesu, E. | Getachew, T.
Development of winter wheat blotches depending on fungicide treatment schemes and nitrogen rates
2020
Svarta, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Bimsteine, G., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Gaile, Z., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Stanka, T., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Daugavina, L., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Pluduma-Paunina, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
One of the factors affecting winter wheat grain yields are leaf blotches. The two-factorial trial was conducted in the Research and Study farm ‘Pēterlauki’ in 2017/2018 and 2018/2019 (Latvia). Four nitrogen rates and five fungicide treatment schemes were used. The aim was to clarify the impact of leaf blotches on the winter wheat yield. In winter wheat plots, the tan spot (caused by Pyrenophora tritici-repentis) dominated but also Septoria leaf blotch (caused by Zymoseptoria tritici) was found. The severity of leaf blotches in winter wheat was low in both years due to dry and warm weather. The development of leaf blotches was influenced by fungicide application schemes, but not by nitrogen fertilizer rate. The total disease impact during the vegetation period was estimated by calculation the area under the disease progress curve (AUDPC). AUDPC for both diseases were significantly higher in the variant without fungicides (F0) and in the variant, where half of dose of fungicides at the growth stage (GS) 55–59 (F1) was used. The using of full dose of fungicide at the GS 55–59 (F2) as well as using of fungicides two (F3) or three (F4) times in growing season significantly decreased the values of AUDPC for both diseases, but differences among AUDPC values in mentioned three variants were not significant. Results showed that the nitrogen fertilization significantly increased the average per both years grain yield until the nitrogen rate N180. Fungicide treatment schemes had no significant effect on the average grain yield.
اظهر المزيد [+] اقل [-]Occurrence of genetic lineages of Puccinia striiformis in Latvia
2020
Feodorova-Fedotova, L., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Inst. of Soil and Plant Sciences;Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Research Inst. of Plant Protection | Bankina, B., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia). Inst. of Soil and Plant Sciences
Puccinia striiformis is a biotrophic pathogen able to cause broad scale epidemics in wheat growing regions. P. striiformis is genetically highly variable pathogen. New, aggressive genetic lineages, adapted to warm temperatures have been observed in the last decades worldwide. The study aimed to ascertain the structure of genetic lineages of P. striiformis in Latvia. Forty one wheat leaf samples with yellow rust symptoms were collected in 2017–2019. Fenotyping and genotyping methods were used for identification of genetic lineages in Global Rust Reference Center, Denmark. Assessments of leaf diseases on winter wheat differentials – ‘Ambition’, ‘Mariboss’, ‘Moro’, ‘Compair’, ‘Rendezvous’, ‘Spalding Prolific’ and local variety ’Fredis’ were made during the research. Five genetic lineages of P. striiformis – PstS4, PstS7, PstS10, PstS13 and PstS14 were found. 56% from the samples belonged to PstS14, 17.1% PstS10, 12.2% PstS4 and PstS7, 2.4% PstS13. Genetic lineages identified from Latvian wheat samples are found in the biggest cereal growing regions in Europe and are able to cause epidemics on wheat. Genetic lineages of P. striiformis from Latvian samples have not been identified before. All differential varieties were infected with P. striiformis in 2017, ‘Ambition’ and ‘Moro’ in 2018, no infection was observed on differentials in 2019 despite the presence of P. striiformis on winter wheat variety ‘Fredis’. The identification of genetic lineages of P. striiformis on wheat in Latvia is necessary to continue.
اظهر المزيد [+] اقل [-]Open geo-spatial data for sustainable forest management: Lithuanian case
2020
Tiskute-Memgaudiene, D., Vytautas Magnus Univ., Kaunas (Lithuania) | Mozgeris, G., Vytautas Magnus Univ., Kaunas (Lithuania) | Gaizutis, A., Forest Owners Association of Lithuania, Vilnius (Lithuania);Vilnius University (Lithuania)
In Lithuania, forests are managed by Lithuanian State Forest Enterprise, municipalities, ministries, etc. and private forest owners. About 50% of all forest land is State importance, privately owned forests cover 40% of forest land, and about 10% of forest land belongs to forests reserved for restitution. Forest management of private ownership force many challenges, because private forest owners are people, who have purchased or received the property after restitution, and often lacks knowledge about forest resources, its dynamics and sustainable forest management. As remote sensing is a valuable source for forest monitoring, because it provides periodic data on forest resource and condition status, these methods are gaining increased attention worldwide. In this context, more scientific efforts are made at developing remote sensing derived geo-spatial data services for sustainable forest management through a web service platform, which would integrate geo-information into daily decision making processes and operation for private forest owners. This article presents a review of privately owned forests’ statistics, questionnaire-based survey about GIS usage and demand for forest owners in Lithuania and links available sources of open geo-spatial data useful for sustainable forest management.
اظهر المزيد [+] اقل [-]Carbon stock in litter and organic soil in drained and naturally wet forest lands in Latvia
2020
Butlers, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia);Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Lazdins, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
The aim of the study is to evaluate carbon stock in litter and organic forest soils in Latvia as well as to characterize accumulation of carbon in litter in afforested lands. The study is providing empirically valid information about soil and litter carbon changes for the National greenhouse gas (GHG) inventory by using data from National forest inventory (NFI), forest soil monitoring demonstration project BioSoil and other studies. The study proves significance of organic forest soil carbon pool in Latvia and demonstrates necessity to extend NFI incorporated forest soil monitoring program to improve data on soil density in wet organic soils, as well as to integrate data characterizing water regime in forests. The acquired data also proves that the conservative approach of calculation of carbon stock changes in litter in afforested lands applied in the Latvia’s National GHG inventory avoids overestimation of CO2 removals. The data on litter carbon stock collected in this study is sufficient to estimate total carbon stock for stands dominated by most common tree species and long term impact of changes of species composition. Measurements of organic soil and litter thickness should be continued by NFI and integrated with more detailed soil monitoring to increase accuracy of carbon stock estimates and gather data necessary for verification of modelling data, particularly in afforested lands and due to change of dominant species.
اظهر المزيد [+] اقل [-]Evaluation of productivity and costs of Malwa forest machine in sanitary fellings in Latvia
2020
Zimelis, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Kaleja, S., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Ariko, S., Belarusian State Technological Univ., Minsk (Belarus)
The topicality of the study is determined by the increasing demand for sanitary felling services currently mainly provided by manual work. Harvesting using hand-held motor instruments is a physically hard work whose costs are increasing rapidly, but labour availability is declining. In sanitary cuttings, additional complications are caused by the use of conventional machinery in harvesting, which necessitates the creation of wide (4 m) technological corridors and significantly increases the proportion of damaged remaining trees in a stand (according to past studies, a set of middle-class forest machines in thinning of spruce stands results in 4–5% of damaged trees, but in pine stands – in approximately twice less damaged trees than in spruce stands). The compact class forest machines in thinnings result in mechanical damage to not more than 1% of remaining trees. During field trials in sanitary felling 9329 trees were felled. The average productivity, working in one shift, is 5.35 m**3 hE−1 with average stands 10 cm. The cost of harvester’s productive hour is 92 € but of a forwarder it is 78. The compact class forwarder creates significantly smaller impact on the soil by reducing ruts depth and soil compaction, which is especially important in sanitary fellings and extraction of seed trees in regenerated areas.
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