Heavy metal extraction study was performed using five chelating agents with different biodegradability: EDTA, EDDS, MGDA, SCLC and citric acid. Aminopolycarboxylic acids EDDS and MGDA showed high heavy metal extraction capability from sewage sludge and sludge-soil mixtures. According to heavy metal removal efficiency investigated chelants can be ranked in the following order: EDTA≈ EDDS≈ MGDA> CA> SCLC. Extraction efficiency from sludge mixtures with clay soil was markedly lower than from the mixtures with sandy soil. Biodegradability of EDTA, MGDA, EDDS and CA was evaluated measuring BOD in water environment over 28 day period. According to the results of biodegradability test after 28 days the ranking order of the chelants was following: EDDS (99%)> CA (32.4%)> MGDA (29.2%)> EDTA (14.9%). Results showed that significantly easier than EDTA biodegradable chelating agents, such as EDDS and MGDA, can be successfully used for heavy metal removal from sewage sludge as well as metal-contaminated soil.  

A study was conducted to determine the productivity and management of indigenous chickens of Kumi district in Eastern Uganda. Eighty households were randomly selected to respond to a standard questionnaire. The average flock size per household was three cocks, six hens and four chicks. Sexual maturity is attained at 5.5 and 6.5 months among male and female chickens respectively, with age at first egg ranging between 5.5-7 months. Egg hatchability varied widely between farmers with an overall mean of 90%. Clutch sizes ranged between 4-19 eggs per clutch, with a mean of 13 eggs. Chickens were acquired through purchase (65.6%), gifts (26.3%), or in exchange for labour. Scavenging was the major feeding system, seasonally supplemented with cereal grain. The majority of the farmers (87.5%) provided birds with drinking water. Death of chicks was prevalent (73%) and was mainly attributed to Newcastle disease (70%), with most of the mortality being observed during the dry season (62%). Survival of chickens was significantly affected (P<0.001) by feeding level, and strongly correlated (r = 0.83) with the housing system. Housing and feeding had significant effects on duration between laying cycles (P<0.001), how chickens were acquired (P<0.01), and the uses to which the chickens were put (P<0.001). Chickens and eggs are mainly used to generate household income and for home consumption. In some households, chickens are exchanged for goats and subsequently, for cattle. Our findings indicate that the indigenous chicken is a major resource in Teso, Uganda. The performance of these indigenous chickens would significantly improve with better feeding, housing and health management. Chicken farmers should be empowered through training and provision of capital credit, the latter of which should be well informed by data on the chicken production cycle.

peer reviewed | Lactation persistency (LP) has been neglected over time in genetic evaluations of dairy goats. The main reason for this is the difficulty to infer about the lactation curve shape. However, some lactations models such as Wood seem to be appropriate to provide persistency estimates under biological viewpoints. The aim of this study was to fit the Wood lactation model as well as to calculate and evaluate LP as selection criteria in dairy goat breeding programs through genetic parameters estimates. A total of 23,265 first lactation test day milk yield observations from 900 animals were used. The Wood random regression model was primarily fitted to estimate the lactation curve parameters (a, b and c), and then LP and total milk yield (TMY). Posteriorly, a multi-trait animal model was fitted considering simultaneously LP and TMY. The heritability estimates were 0.31 and 0.04 for TMY and LP, respectively. Based on the low LP heritability, selection based only on this trait might be inefficient. In conclusion, the results of this study suggests that selecting for high milk yields might result in high persistency since the genetic correlation between LP and TMY was moderate (0.39).

The research was done in 2006 with the aim to observe the earliness and sugar content of melons (Cucumis melo L.) in Tukums region of Latvia. Five lines of Latgale's melons ('8', '14', 'S4(3)', '5(2)', and '4(3)') and five varieties ('Noirdes Carmes', 'Ogen', 'Vedrantais', 'Cantaloup de Bellegarde', and 'Jaune Canaris') from South Europe were grown in high plastic tunnels: five plants from each line and variety. The most appropriate melon line for growing in Latvia conditions was selected according to earliness and sugar content. The study showed that Latgale's melons (Latvian origin) are most suitable for growing in high plastic tunnels under Latvia's conditions. Also some of South Europe melon varieties proved to be suitable for growing in Latvia conditions. All Latgale's melon lines were earlier than South Europe varieties. The highest sugar content was observed in Latgale's melon line '8' (113 g kg¡1) and in South Europe varieties 'Jaune Canaris' (110 g kgE-1) and 'Cantaloup de Bellegarde' (96 g kgE-1). The research demonstrated that in Latvia successful cultivation of melons is possible by using high plastic tunnels.

The aim of this research is to evaluate the variability of the martagonlily (Lilium martagon L.) found in the wild in the west of Latvia. Latvia is situated in a nature zone between the vegetation of Northern and Central Europe. The country distinguishes itself with a large variety of flora and fauna (total approx. 27, 7 thousand species). The genus Lilium L. includes approximately a hundred species, subspecies and varieties of species. In northern Europe, one of the best known and longest cultivated of lilies is L. martagon L. It is distributed across the largest growing area of most species - from western Portugal throughout Europe and Asia. To evaluate the survival potential of L. Martagon L. in Latvia, research was carried out in locations at Kurzeme - districts of Ventspils, Kuldiga, and Tukums. The results indicate that the diversity in genotypes varies according to location and distribution. There are differences in phenotypes and colour variability from pale to bright violet-pink. Diameter of flower varies between of 3.5 to 6.0 cm. The height of these plants varies up to 114 - 130 cm. The flowering time is in June and July. Wild martagonlily found in these regions is growing in calcareous soils among shrubs in river valleys and semi-shaded deciduous forests. This particular martagonlily is hardy and disease resistant and is recommended as a donor in breeding programs.

Neosporosis is an infection disease caused by a single celled parasite Neospora caninum that produces cysts in the host organism. The dogs are a definitive host of parasite; cows and other ruminants are intermediate hosts. It causes neuromuscular disorders in dogs and abortions, birth of weak calves and neonatal mortality in cattle. Disease occurs worldwide (Sweden, Germany, Spain, Australia, Canada, USA et al.). Our aim of this study was to clear up how many seropositive animals in two seropositive dairy herds (after bulk milk investigation) in Latvia there are, their relationship and possible changes of their biochemical data. The studies in 2006 between September and November were carried out. In two farms there were 14 seropositive animals (from 67). There was evidence of inheritance of neosporosis infection. No differences were recognized in cows' blood biochemical data between positive and negative animals.

The mean content of minerals in grains varies significantly among different parts of the world as it depends on the type of grain growing conditions and fertilizer application. In this study, the content of minerals in the wheat, oat and barley grains of the crop of the year 2006 from different regions of Latvia were investigated. The grain samples were analysed for K, Mg, Ca, Na, Cu, Mn, Fe, and Zn using Atomic Absorbtion Spectrometer, and for P using spectrophotometer. Phosphorus content in different types of grains varied from 3.10 to 5.65 g kgE-1, potassium - from 4.37 to 6.10 g kgE-1, calcium - from 0.40 to 1.40 g kgE-1, magnesium - from 1.20 to 1.68 g kgE-1, manganese – from 14.50 to 55.54 g kgE-1, copper - from 3.35 to 6.01 g kgE-1, zinc - from 18.72 to 31.84 g kgE-1, iron - from 42.39 to 120.40 g kgE-1, and sodium - from 32.34 to 55.52 g kgE-1. The greatest difference was found between the content of manganese and iron in barley, wheat and oat grains, but small difference was between the mean content of P, K, Zn, Cu, Mg, and Na.

In presented study we have investigated an occurrence of 15 polycyclic aromatic hydrocarbons (PAH) in different smoked meat and fish samples. After clean up and extraction procedures, the samples were analyzed by gas chromatography-mass spectrometry (GC-MS). Large variability in PAH levels for samples of the same type was found, thus the contamination level is not strongly correlated with the type of product. In the smoked fish samples concentrations of total PAHs ranged from 0.26 to 104 mu g kgE1, and in smoked meat samples - from 1.7 to 197 mu g kgE-1. In general, the predominating PAHs in all samples were benz(a)anthracene, crysene, and cyclopenta(c,d)pyrene. Also the elimination of PAHs in smoked fish by UV irradiation was investigated. Significant decrease in carcinogenic PAH content in smoked fish was found after a 15 min exposure.

The aim of the research was to assess food safety risks in catering establishments. To analyse food safety risks during production and distribution of ready-to-eat food in catering establishments, internal database of the Food and Veterinary service of the Republic of Latvia was used. Catering establishments, food items, technological processing methods, as well as environmental objects were encoded to perform mathematical analyses of state's monitoring and surveillance data. The probability of the microbiological risk factors coliforms and S.aureus in food and environmental samples as well as the total plate count in ready-to-eat food was assessed to forecast common risks in catering establishments and to set hygiene management priorities in frame of HACCP procedures. For estimation of individual risk factors, results were statistically analysed using SPSS statistical package and a p is less than 0.05 was considered to be statistically significant. The significant differences were established between certain bacteria presence in food and such factors as food group, method of technological processing, and type of catering establishment. The results on bacterial contamination of food correlate with the results on contamination of environmental objects. The research suggests that control of food safety risks that is built on testing of pathogenic bacteria is not effective enough to evaluate actual level of implementation of hygiene measures in catering establishments. Risk assessment during routine monitoring both in state's official control level and catering establishments' self-control level should be concentrated on testing of hygiene indicator microorganisms rather than pathogenic microorganisms to establish and prevent food safety risks.

A total of 120 food samples from 6 traditional and 3 non-traditional (Oriental) public catering establishments in Latvia were taken. Preliminary all food samples were divided in three food groups (categories) depending on the components of the products and processing methods. Ready-to-eat foods (RTE) with high level of total amount of microorganisms (aerobic colony count-ACC) and total coliforms (TC), as well as appropriate infringements of hygienic requirements in public catering establishments which had an impact on microbial contamination were clarified. The reasons for microbiological contamination of RTE and the growth of the microorganisms were analyzed in dependence on food category group, the activity of hydrogen ions (pH) in food, food temperature at the sampling point, their processing mode and composition. Different indicator microorganisms including Staphylococcus, Enterobacter, Escherichia, Bacillus, yeasts, moulds and etc. were identified. The comparison between the temperature and pH and the level of microbiological contamination of the samples of food and hygienic practice in the catering establishments were clarified.