This study was undertaken to assess the potential for sweet potato silage making business by estimating sweet potato vines and root wastage and assessing the economic feasibility of investing in sweet potato silage. Information was collected through key informant interviews, secondary data review, sweet potato root peeling and weighing, focus group discussions with pig and sweet potato producers covering a sample of 180 farmers. Semi-structured interviews with 240 respondents (120 sweet potato farmers, 60 pig farmers and 60 sweet potato traders) were also conducted. The results showed that sweet potato production is seasonal with substantial wastage of sweet potato components existing across the various nodes of the sweet potato value chain. The study concludes that there is an opportunity for investment in sweet potato silage business that has the potential to reduce wastage of sweet potato and bridge the feed scarcity gap faced by pig farmers.

The objective of this study was to estimate genetic parameters of reproduction traits of pure Fogera cattle at Metekel Ranch. Metekel cattle Breeding and Improvement Ranch has so far been engaged in maintenance of Fogera cattle population outside their adapted environment (ex-situ conservation). The breeding program has two components: selection and crossbreeding. The establishment of the pure breed unit is meant for the improvement of the Fogera breed and for providing heifers to cross- breed to exotic dairy sires (by Artificial insemination). In cross breeding program; crossbred animals are produced through artificial insemination of Fogera cows with Friesian semen. Around three to six months of pregnancy, the F1 cross heifers are sold to farmers for milk production (Melaku et al., 2011a, b). Very recently the ranch started to distribute non pregnant F1 cross heifers. WOMBAT software was used to estimate genetic parameters. The variance components and heritability were estimated using a Uni-variate animal model using four models which fitted direct additive, dam genetic and permanent environmental effect as a random effect and the fixed effects (year, season, sex and parity). Parameter of age at first calving (AFC) were estimated using Model 1 (Y= Xb + Z1a + e), Model2 (Y= Xb + Z1a + Z3c + e), Model3 (Y= Xb + Z1a + Z2m + e (cova, m = 0), and Model4 (Y= Xb + Z1a + Z2m + Z3c + e (cova, m = 0) whereas parameters of reproductive traits including gestation length (GL), calving interval (CI) and days open (DO) were estimated using model 2 and 4 which fit permanent environmental effect due to repeated records per cow. Correlations (genetic and phenotypic) among the different traits were estimated from bi--variate analysis by using model 1 for growth traits and AFC and model 2 to estimate the correlation between CI, GL and DO and birth weight (BWT) and GL. Correlation between birth weight and gestation length were estimated by treating gestation length as a trait of calf. Due to record limitation correlation between AFC with other reproductive traits were not estimated. Estimates of direct heritability of reproductive performance traits from the best model were 0.003 ± 0.05 for AFC, 0.00 ± 0.03 for GL and CI and 0.013 ± 0.03 for DO. The phenotypic correlations between reproductive traits were 0.003 ± 0.034 for CI and GL, 0.37 ± 0.041 for CI and DO and 0.167 ± 0.036 for DO and GL and the genetic correlation between reproductive traits ranged from -0.94 ± 0.2 for DO and GL to 0.83 ± 0.579 for CI and DO. Genetic correlation between growth and AFC ranged from 0.77 ± 0.24 for BWT and AFC to 0.87 ± 0.03 for pre-weaning average daily gain (PADG) and AFC. The phenotypic and genetic correlations between BWT and GL were 0.03 ± 0.05 and -0.84 ± 0.013 respectively. The results of genetic correlation between considered traits was ranged from moderate to high and it indicates that selection for one trait would have a significant effect on the other traits not considered however selection must be done with caution. The heritability estimates confirmed the presence of high environmental effect among the study population and it masks the individual animal genetic difference. Given the low heritability estimates obtained, effective improvement in reproduction performance of Fogera cattle could be achieved by improving the production conditions and through crossbreeding.

Methane is considered to be the main greenhouse gas (GHG) emitted by livestock. One method for reducing methane emissions from ruminants is to improve production efficiency, which reduces methane emissions per unit of product (FAO, 2010; Gworgwor, Mbahi, and Yakubu, 2006). There are many researches about prebiotics which can reduce methane production in livestock, for example, galacto-oligosaccharides reduced methane emission up to 11% (litres/day) (Zhou et al., 2004). There is almost no information about prebiotic inulin, so the aim of this research was to determine the impact of different dosages of inulin concentrate (50%) on the increase of calves’ body weight and its impact on methane emission, as well as to find out how the results change if it is added to barley flour not to milk as in our previous research. Approximately fifty days old, clinically healthy, different Holstein Friesian crossbreed calves kept in groups of 8, in a partly closed space with natural ventilation through windows were included in this research. Eight calves were in the control group (CoG) and sixteen received inulin (Pre12 (n = 8), Pre24 (n = 8)). At the beginning of the experiment – the 28th and 56th day - we determined each calf’s weight and measured the methane level in the rumen by using the PICARROG-2508 gas analyser (Fleck, 2013). We concluded that inulin supplement significantly (p ≤ 0.05) increased the live weight gain comparing Pre24 and CoG. The highest methane production on 1 kg of body weight at the end of the research was detected in Pre24 – 1.24 mg mE-3 and the lowest in CoG – 0.99 mg mE-3.

Wheat crown rot is a harmful disease that can be caused by different pathogens. The control of this disease is complicated because of the diversity of pathogens and an insufficient efficacy of fungicides; therefore, the agronomic practices of wheat production are an important tool for reducing the disease development. The aim of this study was to estimate the incidence of wheat crown rot depending on soil tillage system and on the pre-crop of wheat in the year 2016. The field experiment was carried out at the Research and Study farm ‘Peterlauki’ of the Latvia University of Agriculture in the autumn of 2008. The data obtained in 2016 are analysed in this study: A – soil tillage system: 1 – traditional soil tillage with ploughing at the depth of 22 – 24 cm, 2 – reduced soil tillage with disc harrowing up to the depth of 10 cm; B – pre-crop of winter wheat: 1 – wheat, 2 – oilseed rape, 3 – faba beans. The incidence of crown rot was not influenced by soil tillage system, but the impact of pre-crop was significant (p = 0.006). The level of disease was essentially higher in continuous wheat sowings. The experiments showed that the main causal agents of the disease were Fusarium spp. and Oculimacula spp. The spectrum of pathogens was not dependent on a particular agronomic practice.

Organic farmers need varieties adapted to variable growing conditions, because in organic farms environmental conditions significantly vary in soil nutrient status, weed and disease pressure not only between years, but also among farms within a season. Modern varieties developed under high input agricultural systems do not always perform well under organic growing conditions. Therefore, farmers need such varieties of cereals that can adapt to variable growing conditions and maintain productivity. One of the ways to promote adaptation to environment is growing of variety mixtures. Field trials were conducted during 2014 – 2016 under organic and conventional farming systems in two locations with an aim to estimate the advantages of barley mixtures in respect of yield and its stability. The trial consisted of eight mixtures of barley varieties and breeding lines, components of mixtures in pure stand and three check varieties. The mixtures were combined by using two, three and five components. Three mixtures, each in one out of 11 environments significantly out–yielded, but one mixture had significantly lower yield than the average value of their components. Some mixtures showed a tendency to out–yield the average of components in both farming systems. All mixtures insignificantly out–yielded check varieties in 2015, but in 2016, yield was within the range between varieties with lowest and highest yield. The results of yield stability analysis showed that mixtures could be used as one of the approaches to stabilize yield – only one of eight mixtures had a lower yield than the average over all environments.

The agronomic role of legumes in cropping systems is well understood with the respect to N2 fixation, mechanisms of precrop effects, and environmental impacts. The combined inoculation and tripartite symbiosis between leguminous plants, Rhizobium spp. and vesicular-arbuscular mycorrhizal fungi has been the subject of intensive research. Less attention has been paid to their effects on subsequent crops. Pot experiments were carried out in the greenhouse of Latvia University of Agriculture in 2015 and 2016. Soil used for this experiment was taken from the previous trial, where broad beans (Vicia faba var. major Harz.) were grown. Bean seeds, depending on the variant, were inoculated with rhizobia bacteria or mycorrhiza fungi, or the mixture of both microorganisms. Onions were grown as a subsequent crop. During the experiment, fresh and dry weight of onion leaves was determined. Onion root mycorrhizal colonization frequency and arbuscule abundance in the onion root system were determined. The activity of soil microorganisms was determined by soil respiration intensity. Results showed that the use of microsymbionts increased the subsequent onion leaf harvest in 2014 by 2.3% and in 2015 by 9.5%. In 2015 the highest increase of onion leaf yield was detected in variants were rhizobia strain RP023 was used. Rhizobia strain RV407 gave a positive effect only in combination with mycorrhiza fungi. Precrop treatment with mineral nitrogen fertilizer increased the onion yield in both years – by 12.4 and 14.3%, respectively. In all treatments, a decrease in dry matter content was observed. The highest incidence of mycorrhiza fungi structures was detected under mycorrhiza treatment. Tripartite symbiosis promoted the soil respiration rate.

Cattle fattening, first of all, should be beneficial for a farmer, therefore, in Latvia more suitable are such average intense fattening methods as fattening with grass fodder. In the world, demand for beef, produced in an environmentally friendly manner, ensuring the appropriate animal welfare conditions, is growing. The aim of the study was to find out the fattening results of Hereford (HE) and Aberdinanguss (AB) pure-bred bulls and their crosses when fed with grass fodder. The study was conducted in 2015 and 2016 within the framework of the project ‘Baltic Grassland Beef’. AB crossbreed bulls were slaughtered when they were 519 ± 16.6 days old, but HE pure-bred bulls − 584 ± 7.3 days old (p ≤ 0.05). The biggest live weight and slaughter weight showed HE crossbreed group bulls – 557 ± 19.4 kg and 293 ± 12.2 kg, respectively, but the biggest live weight daily gain from birth to slaughter was observed to AB pure–bred group bulls – 952 ± 24.7. Carcass conformation score in muscle development was the highest for AB pure–bred group bulls. Their average conformation score was 3.2 ± 0.08 points. In terms of fat score development, carcass with the best quality was obtained from HE crossbreed group bulls, the resulting fat score – 2.4 ± 0.10. The obtained results prove that pure-bred and crossbreed bulls used in this research are suitable for fattening with grass in the conditions of Latvia

The aim of our study was to determine up to what extent the number of services per calving (NSPC) affects dairy cow productive and reproductive performance. The study contains data from the Agricultural Data Centre of Latvia about 26888 Latvian Brown (LB) and Holstein Black and White (HBW) breed cows that were born from year 2005 – 2010, closed at least 5 full lactations and were culled from herds. In data set we have included data about cow milk productivity (calculated in ECM), longevity traits and reproduction traits. The reproduction traits included the number of services per conception (NSPC), calving interval (CI) and calving to conception interval (CCI) in the first five lactations. The average lifespan of LB and HBW dairy cows was 3149.5 days and in this period 39570.6 kg ECM were obtained. LB breed cows were characterized by 23.5 days longer lifespan and by 6035.4 kg ECM lower lifetime milk productivity than HBW breed cows, but they showed higher reproduction trait scores than LB breed group. HBW cows had a significantly (p is less than 0.05) higher NSPC, CCI, number of milking days (MD) and CI than LB breed cows in all five analysed lactations. The NSPC in the first lactation increased the calving age at the fifth lactation – cows with NSPC in the first lactation is greater than 4, fifth time calved 170.7 days in LB breed group and 190.8 days in HBW breed group later than cows with one NSPC in the first lactation.

It is important for every country that its territory develops evenly and in a balanced way. In the European Union (EU), a special focus is placed on the development of rural territories, as predominantly rural regions in the EU represent 57% of the territory and 24% of the population. In Latvia, the development of rural territories depends on economic growth in the key industries for the rural areas – agriculture and forestry, and logging that contributed to 4.3% of GDP and employed 9.5% of the labour force in 2011. Therefore, the research aim is to perform an assessment of the administrative territories of Latvia. The research analysed the municipalities of Latvia in terms of population and change in the population as well as in terms of revenue and income and change in the revenue and income. The research found that in Latvia the best economic performance was demonstrated by the municipalities with a population in the range of 8-12 thousand. In the period 2004 – 2014, the number of residents decreased by more than 20% in 49 municipalities of Latvia. Such municipalities are located far away from the capital city, and poor economic performance indicators with a prevailing primary sector were typical of the municipalities. The municipalities with higher tax revenue had larger populations, which increased in the period of analysis, and such municipalities are located in the vicinity of Riga and high economic performance indicators were characteristic of them.