β-Carotene (BC) and a-tocopherol in milk fat have positive implications in human nutrition, besides the specifically protecting polyunsaturated fatty acids from oxidation. To determine the possible effect on some milk components, nutritional value and lipid stability of including carrots in the diet of lactating cows, ten cows were selected in a dairy farm and divided into 2 groups (control and experimental) by 5 cows in each. In experimental group's diet additionally 7 kg carrots per cow per day were included. Individual cow milk samples were obtained 1 day before feed enrichment, in days 7, 24, 35, 42 (during the feed enrichment), and 1 week after feed enrichment. Analyses of milk fat, protein content, somatic cell count (SCC), retinol, BC, vitamin C, tocopherols, immunoglobulins (Ig), lysozyme, fatty acids (FA) were made, and milk yield was measured. Supplying cow diet with carrots showed a tendency to improve milk quality by promoting the faster decrease of SCC, and significantly (p is less than 0.05) increasing Ig and lysozyme content, thus potentially improving milk nutritional value. The vitamin content rose significantly (p is less than 0.05) by retinol and tocopherol contents, but b-carotene content increase in milk was not observed. Also milk fatty acid (FA) stability changes during 5 day storage in temperature of 4 - 6 deg C were not observed.

Within the frame of the Nordic/Baltic public-private partnership ’PPP for pre-breeding in perennial ryegrass’ various activities were performed, including assessment of L. perenne (Lp) genotypes under agro-ecological conditions of Latvia. This article summarizes the data obtained in two harvest years for 19 intermediate tetraploid (4x) Lp genotypes. In order to compare the results obtained in ryegrass with performance of grass interspecies hybrids (Fl), which become especially relevant in the recent years, two varieties, developed in Latvia – Lolium × boucheanum Kunth. ‘Saikava’ and × Festulolium ‘Vizule’ were included in the experiment. Various scores were performed, including evaluation of regrowth, intensity of culm development, sward cover, crown rust (Puccinia coronata) susceptibility, etc. The dry matter yield (DMY) and fodder quality were also determined. It can be concluded that the genotypes showed relatively good results in the first two harvest years. Wintering conditions were favourable. Despite the intensified drought and heat in the 1st ley year, relatively high DMY, which ranged from 9.30 to 12.15 t haE−1, for Lp were harvested in three cuts. In the 2nd ley year, under more favourable humidity conditions, Lp in four cuts provided similar DMY, which ranged from 8.81 to 11.50 t haE−1. If we compare the average DMY of Lp and Fl genotypes, it can be concluded that in the first two harvest years no significant differences were found, the average DMY was 10.30 and 10.64 t haE−1, respectively. No significant differences were found between Lp and Fl in terms of forage quality.

This research was conducted to determine the chemical composition of smooth bromegrass in artificial pasture from the years 2010 to 2012 in Isparta Province located in the Mediterranean region of Turkey. The mixture of the pasture used were alfalfa (Medicago sativa L.) + sainfoin (Onobrychis sativa Lam.) + crested wheatgrass (Agropyron cristatum L.) + smooth bromegrass (Bromus inermis L.). Animal grazing applications were performed in the second and the third year of the study since the first year covered only the establishment of the artificial pastures. Forage samples were collected from grazing and non-grazing areas once every 15 days during the grazing seasons. The crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF) contents, total digestible nutrient (TDN) and relative feed value (RFV) were determined on the smooth bromegrass forage samples. According to results, CP, TDN and RFV values decreased throughout the grazing season, while ADF and NDF contents increased in grazing and non-grazing areas. The ADF and NDF contents of smooth bromegrass in non-grazed areas were higher than the grazed areas, while CP, TDN and RFV values of grazed areas were higher than non-grazed areas. It can be concluded that the harvesting at the late stages caused a reduction in forage quality of smooth bromegrass in grazing and non-grazing areas.

One of the main preconditions for an economical milk production is a balanced cow feeding that contains high quality grass forage. Chemical composition of cocksfoot forage during vegetation was investigated at the Research Centre "Sigra" in the Biochemical laboratory of the Latvia University of Agriculture. Changes in the content of crude protein, NEL MJ kg*[-1) of DM, NDF, ADF and DM digestibility were determined. The chemical composition of grass forage depends on many factors, the most significant of which is the harwesting time. The feeding value of the cocksfoot grass decreases during its growing stages as the content of fibre increases and becomes lignified.

During the period of 2000 and 2001, field trials were established with the aim to evaluate the productivity and forage quality of lucerne. The most productive lucerne varieties were 'Birute', 'Radius' and 'Belorusskaya' yielding 13.5-14.6 t ha*[-1) DM, during the years of sward use. The most content of crude protein 170-175 g kg*[-1) have been obtains from 'Karly', 'Radius' and 'ABT-205'. The highest digestibility was observed in the developing line No 60. Acclimatization of rhizobia within lucerne roots has been determined applying streptomycin resistant forms. In field conditions acclimatization within lucerne was more successful by strains 05 (40-100%).