The objective of this study was to compare the growth performance of two Nguni ecotypes and its crosses (Nguni x Landim) raised under the same feedlot conditions at the Posto Fomento do Impaputo, in southern Mozambique. Live weight feedlot data, from entry to marketing, were collected every fortnight between 1999 and 2009 from 453 oxen of the Nguni and Landim male ecotypes, as well as the crosses. Year-season of birth had significant effects on live weight at entry in the feedlot and at marketing age. Overall means for average age at entry in the feedlot was 31.8 ± 4 months, with the Landim being younger than the Cross (p=0.07). The average live weight at entry in the feedlot was 390 ± 42.5 kg, with no differences between ecotypes (p>0.05). Males born in dry year-seasons were heavier than males born in wet years-seasons (p<0.0001 to p<0.05).The average age at marketing of the Nguni ecotypes was 34.4 ± 5.08 months, with the Landim being younger (p<0.05) than the Cross. The average live weight at marketing was 446 ± 42.2 kg. The average live weights at entry and at marketing were higher in dry years-seasons than in wet years-seasons. There were no differences between ecotypes for average daily gain (0.89 ± 0.79 kg) in this study. Growth rates for the feedlot in the Nguni cattle obtained in this study were substantially lower than that obtained for the Ngunis in South Africa albeit they entered the feedlot at a much older age. This study demonstrates that in Mozambique feedlot industry is still underdeveloped with main constraints on feed resources, especially concentrates.

Aquaculture, a sub-component within the fisheries sector is a vital economic activity and livelihood component of rural communities living beside rivers and river floodplains in East Africa. It provides a good alternative source of income and proteins for rural communities. This study aimed to characterize fish production and marketing practices in smallholder farming systems under a national Economic Stimulus Programme (ESP) in the Eastern province of Kenya, and to determine the traits of economic importance to the farmers. Information was collated from 198 farmers, 13 traders and three key informants within Meru District of Eastern Province. The predominant species of fish reared was the Nile Tilapia, followed by the African Catfish and in some instances a combination of the two species were reared under polyculture. Good growth rate and survival of fish were noted to be the most important traits of economic importance to the farmers. Fish produced was mainly sold to the local community and within local markets. Traders, however, indicated that the demand for fish was much higher than the supply, hence also sourced fish from Lake Victoria in Nyanza for sale. It was also indicated that the taste of fish differed greatly depending on the source, with wild fish strains from Lake Victoria having a “sweeter” taste than the farmed strains. Strains of fish selected for improved growth and reproduction were not available for aquaculture. Feeds and feeding management of farmed fish was also a challenge. It was evident that there is a great need for supportive research on environmental impacts, productivity and quality of fish reared, and marketing of fish products within the riverine environments of Kenya. Key words: aquaculture, fish marketing, traits of economic importance

Pear (Pyrus communis L.) fruits in Latvia are very popular, although orchard areas are not large. In the commercial orchards the control of plant pathogens mainly is performed using a plant protection plan, based on long-term observations. European pear rust caused by Gymnosporangium sabinae (Dicks.) G. Winter has become during recent years one of the most important diseases in Latvian pear orchards. Pathogen G. sabinae has a complex development cycle, with four types of spores on two different plants: pear and junipers. Favourable development of each stage depends on the specific environmental conditions. The aim of the study was field evaluation of the disease severity depending on agro-ecological factors. The study was performed at the Latvia State Institute of Fruit-Growing from 2008 to 2012. The severity of European pear rust infection on leaves of cultivars was evaluated in points 0–5, where: 0 – a tree has no infected leaves; 5 – 81% to 100% infected leaves. The disease severity during these years, impact of tree planting year, rootstock, cultivar and tree location in the plot were analyzed. Results gave the opportunity to determine which factors have positive influence on the development of pathogen and severity of disease. Severity of disease was not directly dependent on cultivar, their country of origin, rootstock and planting year. Severity of disease was influenced by tree location in the orchard; higher severity was observed on larger and more vigorous trees, located in outer rows, exposed to the prevailing wind carrying pathogen spores.

Plants are components of ecosystem that transfer elements from abiotic to biotic environments. Several elements, such as As, Cd, Hg, Pb, can be considered as food chain contaminants. Simultaneously, some essential micronutrients (e.g., Cu, Cr, Ni, Zn) at high concentrations may become toxic to both, plants and animals. To secure the aim to describe the uptake of metals by food crop species such vegetables, as radish Raphanus sativus L., leafy lettuce Lactuca sativa L. and dill Anethum graveolens L., were grown in soils of various grading composition and type. There were five soil types selected. A part of soils was contaminated with copper sulphate solution at different target concentrations, while another part was contaminated with mixture of metal (Pb, Cd, Cu, Zn) compounds. In half of treated soil samples the solution of humic substances was added. Harvested vegetables were dried, and after wet digestion with nitric acid quantitative analysis of metal concentrations was performed by use of atomic absorption spectrometry. The highest concentration of copper was detected in vegetable samples grown in soils with less organics, thereby indicating the importance of soil organic matter to metal transfer routes and accumulation rates in plants. Analysis of lettuce grown in soils contaminated with the mixture of metal compounds revealed that zinc was a metal absorbed more intensively, but metal uptake and accumulation was less intensive from peat if compared with other soils.

Ground beetles (Coleoptera: Carabidae) and rove beetles (Coleoptera: Staphylinidae) as predators of many pests and weeds in every crop are significant elements of integrated pest management. Worldwide studies show that ground beetles reflect different soil tillage methods, crop rotation, chemical and genetic pollution, usage of fertilizers and landscape fragmentation. All these factors are the parameters based on which it is possible to assess agriculture whether it is sustainable or not. Ground beetles also can indicate different farming systems and potentially serve as keystone indicators of pest abundance. Thus ground beetles can be good indicators of sustainable agriculture, but rove beetles have a good potential to do it. Researches on crop dwelling ground beetles and rove beetles have been done infrequently in Latvia. Mainly these are faunistic studies not paying attention to agricultural environmental factor effect to ground beetles and rove beetles. For using ground beetles and rove beetles as indicators of sustainable agriculture in Latvia, studies on these beetles reaction to different farming activities should be done. These studies must occur in different crops and different places of country, because ground beetle and rove beetle reflection to changes of agricultural environmental factors may be crop- and site - or even field-specific. Overview of literature on ground and rove beetles’ ecology in agroecosystems recorded in Latvia, other European countries and Northern America has been used for this study.

Horseradish (Armoracia rusticana L.) is a perennial herb belonging to the Brassicaceae family and contains biologically active substances. The aim of the current research was to determine the most suitable extraction method and solvent for obtaining horseradish leaf extracts with high antiradical activity. For experiments fresh leaves of horseradish were extracted with seven different solvents: n-hexane, diethyl ether, 2-propanol, acetone, ethanol (95%), ethanolwater/acetic acid (80/20/1 v/v/v) and ethanol / water (80/20 by volume) using two extraction methods (conventional and Soxhlet). For all extracts, total phenolic, flavonoid content and DPPH˙, ABTS radical scavenging activity, and reducing power were determined using a spectrophotometric method. As the best solvent can be used ethanol. Total phenolic content and total flavonoid content was higher in Soxhlet extracts. Comparing to other plants, the proportion of flavonoids in the amount of total phenolics is average, and it increases by increasing the polarity of used solvent. It can be concluded that by using Soxhlet extraction method it is possible to obtain extracts that are effective antioxidants. A very strong and a strong correlation has been identified between levels of phenolic compounds and antioxidant capacities of the extracts.

Nutritional value and shelf life of milk and dairy products depend on the composition and stability of their constituents. The aim of the present study was to evaluate the effects of carrots as cow feed carotenoid source on butter oil fatty acid (FA) composition and oxidative stability. Milk was obtained from one trial group (TG; n=5) and one control cow group (CG; n=5) in a conventional dairy farm in Latvia. TG cows received carrots 7 kg per cow per day; the length of the supplementation period was 39 days. The stability of butter oil exposed to sunlight (3h) and held for 14 days in the temperature of 60 °C was analyzed by peroxide value method. The changes of the FA content and ratios in TG milk fat were more positive with respect to the fat nutritional value as observed in CG – stronger increase in the content of polyunsaturated FA (p is less than 0.05), and in the ratio between stearic and palmitic acids (p is less than 0.05); also a tendency was seen of increasing content of short and monounsaturated FA, as well as decreasing the ratio between ω6 and ω3 FA groups. Oxidative stability of the carrot supplemented cow group’s milk butter oil samples that were collected after 25- day trial period, exposed to sunlight (3h) and stored at a temperature of 60 °C was significantly (p is less than 0.05) higher compared to CG samples. After the 39-day long trial period stability difference was not significant, despite the tendency that average polyunsaturated FA content in TG samples was higher compared to the control.

The main purpose of the research was to investigate the physically-chemical parameters of organic and conventional hull-less barley (Hordeum vulgare) harvested in Latvia. In the experiment the following hull-less barley harvested in 2012 from the State Priekuli Plant Breeding Institute (Latvia) was used: ‘Irbe’, PR4651, PR3808.21 and PR5099. The following quality parameters of grain – protein, starch, the bulk density and β-glucan content – were measured by standard methods – Infratec™ 1241 Grain Analyser (Denmark) corresponding to ISO 12099; thousand-grain weight (TGW) (ISO 520:2010); the falling number (ISO 3093:2009); moisture content (LVS 272:2000) were also determined. In the present experiments no significant differences in protein, moisture, starch, β-glucan content and TGW were detected, however, significant differences in the bulk density of all analyzed hull-less barley samples were established. The lower analyzed parameter value of 780 ± 1 g LE-1 was obtained for the conventional and organic hull-less barley PR 5099. However, the higher bulk density value of 821 ± 1 g LE-1 was obtained in the conventional hull-less barley variety ‘Irbe’. No significant differences in the bulk density of conventional and organic hull-less barley ‘Irbe’, PR4651 and PR3808.21 were found. Significant differences in the falling number were detected in the analyzed hull-less barley samples harvested in the conventional and organic farming. The lower falling number value was obtained in the organic hull-less barley line PR 5009 – 81 ± 4 s, the higher in the conventional and organic hull-less barley line PR 3808.21 as 362 ± 5 s and 373 ± 2 s, respectively.