The experiment was conducted to analyse the effect of fermented acid whey permeate on milk yield and composition in the lactating cows. Propionic acid bacteria and their metabolites have been used in the lactating cows feeding over decades, primarily to improve growth performance, feed conversation and milk production efficiency. Two groups of the lactating cows were arranged in the study: control group (n=50) and experimental group (n=50). Experimental group’s animals received 0.5 L of fermented whey permeate daily. Acid whey permeate was inoculated with the freeze-dried PS-4 (Propionibacterium freudenreichii subsp. shermanii, Chr.Hansen, Denmark) starter and fermented anaerobically for 48 hours at 20±2 ºC. Fat, protein, lactose and total solids concentration in acid whey permeate and fermented acid whey permeate was analysed by the standard methods, but propionic acid was detected by HPLC. Milk composition and quality indices were determined at the beginning of the study and each month during 6 months period. At the end of the study the feeding of fermented acid whey permeate was stopped, but milk composition and quality data were monitored additionally after one month. Milk fat, protein, lactose, total solids, urea concentration and somatic cell count were analysed by a near infrared spectroscopy. The variability in milk composition and quality data across trial was greater in the experiment group than in the control. Milk fat and somatic cell count were significantly different (p is less than 0.05) than other studied parameters in the experimental group cows’ milk. Milk yield and lactose concentration were tended to increase during feeding of fermented acid whey permeate in the lactating cows without significant differences between control and experimental groups. Fermented acid whey permeate as feed supplement improves energy metabolism for dairy cows which results in the higher milk yield and fat concentration.

Climatic conditions for soybean cultivation in Latvia are challenging because of their variability. In addition, the sum of sunlight hours and the ratio of temperature and precipitation required to produce a quality crop are unpredictable. There is a risk that even early soybean varieties will not ripen due to weather conditions in a region. Studies show that soybean plants, including the green part of the crop, are well suited for animal nutrition prepared as hay or silage. The aim of this study was to evaluate the chemical composition of different soybean varieties harvested before ripening and assess them as hay or silage raw material. Weight, protein, fat, ash, fibre, acid detergent fibre (ADF) and neutral detergent fibre (NDF) of soybean varieties ‘Erica’, ‘Bolgar’ and ‘Viola’ green mass were determined at different stages of maturity. The results of the study showed a significant increase in protein (from 9.18% to 12.06%) and fat (from 1.18% to 4.40%) content of the dry matter variety ‘Bolgar’ from September to October. The protein content of the dry soya green mass was not affected by variety at the same developing stage but significantly changed among different stages of maturity. As the plant develops, the sucrose content in the green mass increases, the same as the total sugar content.

Since plant protein is generally accepted as sustainable and environmentally friendly, production of new plant protein-based products is expanding and a raw material is diversified to ensure a high-value and complete meal. The objective of the study was to compare chemical composition and amino acid provision of pea-buckwheat, pea-barley and pea-oat extruded mixtures with the aim to look for new products to diversify diet using the best plant protein resources. Within the research, amino acid scores of hull-less barley, buckwheat, hull-less oat and grey pea as an indicator of raw material protein quality were evaluated. The highest scores of essential amino acids were found in oat and pea protein. Amino acid scoring patterns of raw material – oat ‘Stendes Emilija’ and grey pea ‘Bruno’ fully meet the requirements for essential amino acid supply. The protein of buckwheat is the richest in lysine (4.3 g 100gE−1 protein) among studied cereals, although the difference in the essential amino acids was not significant. The results of the research showed that pea-barley and pea-buckwheat composite mixtures meet human needs better if pea protein is used in the proportion 65:35 with barley or buckwheat flour than in the proportion 35:65. The high protein content – 43.33% and 43.96%, the sum and composition of essential amino acids, and high level of total dietary fibre – 11.9% and 13.7% are the main reasons to consider the mixtures (including as a base for smoothies) as a complete meal.