Since the middle of the last century rapid intensification of agricultural production systems has resulted in dramatic increase in fertilizer consumption as fertilizer has been considered as one of the most important factors for increased yields. However, not all the nutrient ions in a fertilizer applied to soil are taken up by crops, thus certain amount of the applied fertilizer is lost from agricultural fields leading to increases in nitrogen surplus, nitrogen losses to the environment and harmful impacts on biodiversity, air and water quality. This study aims to focus on crop fertilisation planning which is based on the knowledge of physical and chemical properties of soil and involves performing soil tests, designing a fertilisation plan and its practical implementation as well as calculating the balance of N, and to evaluate crop fertilisation planning as a tool for achieving balanced economic and environmental benefits in crop farming, which play an important role in efficient farming. In this study, the authors have analysed current situation in Latvia regarding requirements for fertilization planning in crop farms and have assessed potential costs and benefits from fertilisation planning. The research finds out that total cost of introducing of fertilisation planning ranges from 34 to 22 EUR haE-1, however, fertilisation planning is a neutral measure where costs are compensated by savings from N inputs which ranges from 10 to 40 kg N haE-1.Fertilisation planning generates environmental benefits, i.e. – reduces direct N2 O emissions from agricultural soils by 47 – 187 kg CO2eq haE-1 through reduced N fertilizer inputs.

Artichokes (Cynara cardunculus L.) contain many minerals, vitamins, fibres, and polyphenols. Environmental conditions and climate change on a global scale affects the overall agriculture and food supply. Composition of biological active compounds in plants depends on the climate and growing conditions, cultivar properties, plant development stage, harvesting time and other factors. The aim of research was to evaluate the effect of agroecological factors on yield and flavonoids content of globe artichoke. An experiment was carried out under open field conditions in Institute of Horticulture, in Pūre investigation fields during the vegetation period of 2014 and 2015. The experiment was arranged in two different soils: brown soil with residual carbonates and the soil strongly altered by cultivation. The yield and its quality were analysed during the whole vegetation period. Higher yield was observed in the soil strongly altered by cultivation. The results showed tendency that the higher flavonoids content in artichoke heads was observed in 2014 than in 2015. Significant differences between flavonoid content per harvest time are observed in both soils.

The research was conducted in Latvia University of Agriculture Research and Study Farm ‘Vecauce’ in 600 dairy cows herd, in the period from 2009 to 2013. Within the framework of the research, growth indicators (from birth till the first delivery) of 102 dairy cow calves were analysed. Live weight and hip height of the heifers were found out at birth, at the age of 6 and 12 months, at first insemination and first calving. Heifers born to primiparous cows in both breed groups had notably lower live weight (42.0 and 42.4 kg), as compared to the 4th group heifers born to mature cows (p is less than 0.05). At the age of one year, the greatest weight among the red breed animals was recorded for the 4th group heifers born to mature cows (on average 354.8 ± 7.09 kg), while in Holstein breed those were heifers born to mothers calving on average for the 2nd time (on average 363.0 ± 6.47 kg). The 4th group heifers born to mature Holstein cows had notably greater hip height at birth – on average 78.1 ± 0.9 cm (p is less than 0.05). Heifers of red and Holstein breeds on average were inseminated at the age of 14.6 – 14.8 months as they reached live weight 395 – 396.5 kg. Heifers of red breeds on average calved at the age of 25.8 months, whereas Holstein heifers - of 26.4 months. The research aimed at analysing growth rates of heifers born to dairy cows at different age.

In Latvia, different breeds of beef cattle are grown; therefore, it is important to explain their suitability to organic farming systems, because most Latvian beef cattle breeders work with organic farming methods. The aim of this research was to compare fattening of different beef breed bulls (Bos Taurus) in organic farming system at similar housing and feeding conditions. In the research, there were included Blonde d’Aquitaine (BA), Hereford (HE), Simmental (SI) and crossbred (CB) bulls. Fattening period started after calf weaning from suckler cows at 7 – 8 months of age. Fattening results were significantly affected by factors like breed, live weight and age before fattening, but slaughter results were significantly affected by breed, live weight and age before slaughter. During the fattening period the biggest daily weight gain was showed for SI breed bulls (849 g), but the biggest live weight increase was recognized for BA breed bulls (295 kg). The required slaughter weight the fastest was reached for XG bulls, which average slaughter age was 532 days (p is less than 0.05). The greatest slaughter weight – 342 kg (p is less than 0.05) and dressing percentage (58% (p is less than 0.05)) was recognized for BA breed bulls; also, carcass conformation score in muscle development was the highest for BA bulls (2.0 points (p is less than 0.05)). The greatest economic benefit was from CB bulls, income calculated per one rearing day from CB bulls was - EUR 1.80.

The diversity of non-starter lactic acid bacteria in raw, pasteurised milk and maturated Swiss type cheese was tested. The aim of the present study was to analyse the concentrations and representatives of non-starter lactic acid bacteria in raw milk and to evaluate the changes of their concentrations and representatives during pasteurisation of cheese milk and Swiss-type cheese production. The analysis carried out in the study showed a variation in the microbial composition and quantity of raw milk. The most frequently isolated lactobacilli were found at low level in raw milk (mean 27.5×104 CFU mLE-1) and the most frequently identified species were Lactobacillus brevis and Lactobacillus paracasei. The microflora of raw and pasteurised milk is similar analysing lactic acid bacteria representatives in the samples. Lactobacillus brevis and Lactobacillus paracasei were detected in the same samples in raw milk, pasteurised milk and maturated cheese. Our study showed that lactic acid bacteria concentration was quite low in pasteurised milk (1-12 CFU mLE-1), but they grow rapidly in cheese during ripening reaching 1.1-1.8*106 CFU gE-1. The present study has shown that NSLAB in Swiss-type cheese mainly derive from raw milk, and only a few strains survive the processing conditions and grow during ripening.

The present study provides research in content of protein, starch, sugars and concentration of B group vitamins (thiamine, riboflavin, pyridoxine and niacin) in immature wheat (Triticum aestivum L.) compared to mature wheat kernels. The content of protein, starch was determined in kernels using Infratec1241 Grain Analyzer (Sweden), content of sugars was analysed by high- efficiency liquid chromatography HPLC (Shimadzu, Japan). The concentrations of vitamins were determined by high-efficiency liquid chromatography for vitamins B1, B2, B3, B6. Obtained results suggested that the immature wheat kernels obtained in milk stage showed higher contents of some compounds such as sugars and B group vitamins. The amount of all sugars presented in immature grains is higher and decreased uniformly during maturation. Therefore, immature grains are better sources of the B group vitamin that the mature grains, and therefore more nutritionally efficacious.

The aim of this study was to determine the influence of Jerusalem artichoke flour feeding on the general health status of calves (Bos Taurus), the animal live weight gain and digestive canal morphological development in the first four months of life, as well as to find out the optimal of three inulin doses. Jerusalem artichoke (Helianthus tuberosus) concentrate produced in Latvia contains the prebiotic – inulin. The study was performed on four groups of animals - a control group of 10 animals and three prebiotic groups, 10 animals in each group. All groups were fed the whole milk, but the PreG6 group animals were fed daily with 6 grams of prebiotic, calves PreG12 group were fed with 12g of prebiotic, but each calf in PreG24 group – 24g of prebiotic per day. CoG control animals did not receive feed supplement. Faecal mass consistence of PreG6, PreG12 groups of animals was more stable within the whole research period than CoG. We found that the control group animal weight gain on the 56th research day is statistically significantly (p is less than 0.05) lower than of those calves that received inulin as a food supplement. The highest growth rates have shown PreG12 and PreG24 group of animals, significantly (p is less than 0.05) being ahead of PreG6 group of calves, the highest average daily live weight gain was observed in PreG24 group (0.95 ± 0.093 kg).

Platelet-rich plasma (PRP) is an autologous concentrated cocktail of growth factors and inflammatory mediators, and has been considered to be potentially effective for cartilage repair. Animal clinical studies suggest that PRP is a promising treatment for cartilage injuries and relieving symptoms due to its three biological properties: an anabolic effect, enhancement of cartilage regeneration and inhibition of inflammation. The aim of this article is to analyse the available evidence on the clinical application of this biological approach to animals for the injective treatment of cartilage lesions and joint degeneration, and also to support the rationale for the use of platelet concentrates and to give indications on what to expect from intra-articular injections of platelet-rich plasma (PRP) in animals. This article is a summary of analytical research papers about the use of platelet-rich plasma as a treatment for the osteoarthritis. The intra-articular injections do not just target cartilage; instead, platelet-rich plasma might influence the entire joint environment, leading to clinical improvement. Many biological variables might influence the clinical outcome and have to be studied to optimize PRP injective treatment of cartilage degeneration and osteoarthritis.

The objective of the study was to investigate the correlation between the milk urea (MU), milk yield and reproductive performance using milk recording tests and the health check results. Weak to average negative correlation was found between MU and the milk yield (r = -0.44 and r = -0.34; p is greater than 0.05), milk protein (r = -0.22; p is less than 0.05) and milk freezing point (r = -0.33; p is less than 0.01). Higher milk fat was found in cow milk with MU below 30 mg dLE-1 in comparison with cow milk which had MU above 30 mg dLE-1, 4.0 ± 0.77% and 3.9 ± 0.75%, respectively. High MU fluctuations within a cow group can be observed if cows of different productivity levels are grouped together or if there are too many animals in one group. Correlations between MU and times of artificial insemination or the service period were not established, possibly due to successful veterinary measures. In conclusion we emphasize the necessity on large dairy farms to analyse MU concentration in relation to milk protein and fat concentration for individual animals and in each feeding group separately. The study was the part of the State Research Project (AgroBioRes) No. 2014.10-4/VPP-7/5; subproject VP29.

After height system replacement in Latvia, there is a transformation formula for point height difference theoretical value in any place of Latvia. Performing practical Global Navigation Satellite System (GNSS) measurements and obtained data mathematical processing, there is also a possibility to calculate point height difference, in this case – practical values. There were thirteen 1st class levelling network points selected in territory of Latvia and got the theoretical and practical values of them. As the result, it is possible to compare height differences between Baltic Normal Height System 1977 and Latvian Normal Height System 2000,5. The practical and theoretical values should coincide, but just 3 of selected geodetic points the height difference comparing practical and theoretical values is close to zero and point height difference of all measured points differs in 17 cm amplitudes indicating problems with transformation formula or need to improve geoid model.