In Latvia the spontaneous sourdough is used in traditional rye bread baking whose microflora is determined in flour and in microorganism cultures presented in external environment. Almost all spontaneous sourdough cultures, especially those that have been maintained for a long time, contain both lactic acid bacteria (LAB) and yeasts. The main purpose of the current research was to analyze growth dynamics of LAB in spontaneous rye flour sourdough and to isolate some of its representatives. Experiments were carried out in the Department of Food Technology of the Faculty of Food Technology of Latvia University of Agriculture in January and February 2008. Considering differences in constituents, two types of flour were used in the research - peeled and crude rye flour. There were three stages of spontaneous sourdough preparation in 72 hours totally; the renewal of sourdough was realized each 24 hours. The dynamics of LAB plate count in every stage of fermentation was investigated as well as changes of pH was observed using standard methods. The results of experiments show substantial increase in amount of LAB in both sourdoughs, particularly in sourdough from peeled flour, reaching 6.06 log10 cfu mlE-1. A significant decrease of pH value from pH 6.7 to pH 3.8 during fermentation process was observed. As a result, the sourdough from peeled flour had desirable properties for preparation of sourdough starter. LAB cultures isolated and identified from current sourdoughs using API tests: Lactobacillus brevis and Lactobacillus fermentum are also typical members of sourdoughs found in other countries.

The objective of the study was to investigate the microbiological content of cow (Bos primigenius) milk in Latvian organic farms according to season and herd size with a purpose to detect their impact on the distribution of mastitis causing pathogens in milk. Samples were collected in 14 organic dairy farms of Latvia, 4 times through 2012: in winter, autumn, spring and summer period. Raw milk samples (n=564) obtained from cow composite milk were studied. The samples were divided into three groups in accordance with the number of cows in the cow-shed: A (3-30), B (31-60) and C (61-124). The total colony count (TTC) and the isolation of mastitis causing bacteria were analysed using standard methods. Bacterial growth occurred in 90.4% of samples. Isolated microorganisms belonged to 35 species, and the following bacteria were the most prevalent agent, including Coagulase negative staphylococci in 29.4%, Staphylococcus aureus in 24.1%, Kocuria kristinae in 12.9%, and Enterobacteriaceae spp. in 10.3% out of 564 milk samples. Depending on the season, the average number of TCC was the lowest in summer (4.66 ± 4.01 log10 CFU mLE-1), moderately higher in spring and winter (4.72 ± 4.18 and 4.82 ± 3.54 log10 CFU mLE-1, respectively), but significantly higher in autumn (5.43 ± 4.80 log10 CFU mL-E1). Coliforms were not isolated from group A herds instead of B (3.1%) and C (4.6%). Occurrence of Staphylococcus aureus was noticeably higher in B (19.1%) and C (20.8%) than in A (12.6%) herds. Most of group A herds met the milk quality requirements, while group C herds produced more contaminated milk.

The present study was undertaken to estimate enzymatically hydrolysed and non–hydrolysed wheat (Triticum aestivum) and rye (Secale cereale) bran microflora. Enzymatic hydrolysis was accomplished by α – amylase from Bacillus amyloliquefaciens and by Viscozyme L which contain a wide range of enzymes responsible for the breakdown of carbohydrates into simple sugars. Wheat and rye bran samples were collected from native mills, namely Stock Company (SC) ‘Rigas dzirnavnieks’ wheat bran with large particle size (WLSR), SC ‘Jelgavas dzirnavas’ rye bran with small particle size (RSSJ), SC ‘Dobeles dzirnavnieks’ wheat bran with small particle size (WSSD) and wheat bran with large particle size (WLSD). Gained results indicate that before enzymatic hydrolysis all of the bran samples showed similar microbiological contamination with total plate count (TPC), yeasts and lactic acid bacteria. Enzymatic hydrolysis of bran gives the possibility to partially eliminate the microbiological contamination with TPC, yeasts and lactic acid bacteria. The amount of microorganisms after enzymatic hydrolysis (before storage) were decreased and ranged from 5.26 ± 0.04 to 5.45 ± 0.01 log CFU gE-1, from 4.81 ± 0.01 to 5.60 ± 0.05 log CFU gE-1, and from 4.09 ± 0.01 to 5.10 ± 0.05 log CFU gE-1, respectively. After eight weeks of storage (temperature – 20 ± 1 °C, relative humidity – 40 ± 1%) enumeration of microorganisms showed significant decrease of colony–forming units in all bran samples. The amount of TPC, yeasts and lactic acid bacteria in the control bran samples fluctuated in a range from 4.84 ± 0.04 to 5.49 ± 0.05 log CFU gE-1, from 4.86 ± 0.03 to 5.25 ± 0.03 log CFU g-1, 3.53 ± 0.03 to 4.21 ± 0.02 log CFU gE-1 respectively.

A study was conducted to determine efficiency of an organic acids and phytogenic additives on pigs' growth processes and digestive tract microflora. The feed of the control group (C) did not contain the additives. The feed of the organic acid group (A) contained 6 kg of organic acids additive per tonne feed for pigs after weaning, 4 kg per tonne feed for grower pigs, and 3 kg per tonne feed for finished pigs. The feed of the phytogenic additive group (F) contained 0.5% of phytogenic additive per tonne feed for pigs after weaning, and 0.2% per tonne feed for grower and finished pigs. The feed of organic acids plus phytogenic additives group (A+F) contained 6 kg of organic acids additive per tonne feed for pigs after weaning, 4 kg per tonne feed for grower pigs, and 3 kg per tonne feed for finished pigs 0.5% of phytogenic additive per tonne feed for pigs after weaning, and 0.2% per tonne feed for grower and finished pigs. Compared to groups pigs from the group (F) had by 9.7%, group (A+F) - by 8.3 % and from group (A) had by 3.2% higher mass. The bests results of feed conversion were found in the group (A+F) - 2.84 kg, which was by 8.5% less than in the group (C), whereas the group (F) had by 5.1% and group (A) - by 6.7% better results than the control group. The results of Duodenum and Rectum microflora analyses showed that use of organic acid and phytogenic additives reduced mould yeast Staphylococcus sp. colony formed units (CFU gE-1).

A study was conducted to determine efficiency of an organic acids additive on pigs metabolic processes and diggestive tract microflora. The pigs of control group were fed without an organic acids additive. The feed of the trial group piglets contained 6 kg of organic acids additive per tonne feed, for starter pigs - 4 kg per tonne feed, for finished pigs - 3 kg per tonne feed. The study indicated that at the age of 130 days, pig mass in the trial group was 54.08 kg an average, but in the control group - 51.06 kg, which showed that pigs from the trial group had by 6% higher average mass than in the control group (p is less than 0.005). At the age of 160 days, pig mass in the trial group was an average 94.3 kg, in the control group - 90.63 kg; pigs from the trial group had by 4% higher mass than in the control group (p is less than 0.005). Feed consumption for the trial group was by 1% less than in the control group. Average daily gain for the trial group was 0.663 kg, which was by 6% more than for the control group pigs (p is less than 0.005). Feed conversion in the trial group was 3.06 kg, but in the control group - 3.275 kg, i.e. 6.4% higher than in the trial group. Analyses of Jejunum microflora showed that use of acidifier additive reduced Mould colony formed units - CFU amount in 1 g of the trial group sample by 6%. Staphylococcus species amount in the trial group was 500 CFU in 1 g of sample, but in the control group - 40000 CFU, i.e. 80 times more. In the trial group, Lactic acid bacteria CFU amount in 1 g of sample was by 6% higher than in the control group. The results of Rectum microflora analyses showed that Staphylococcus species amount in the trial group was 12000 CFU in 1 g of sample, but in the control group it was by 34% higher.

A study was conducted to determine efficiency of a phytoadditive on pig growth processes and digestive tract microflora. The pigs of control group were fed without the phytoadditive. The feed of the trial group piglets contained 0.5% of the phytoadditive per tonne feed, for starter pigs and finished pigs - 0.2% per tonne feed. The study indicated that at the age of 170 days, pig mass in the trial group was 111.67+-1.22 kg on average, but in the control group - 101.79+-0.81 kg, which showed that pigs from the trial group had by 9.7% higher average mass than in the control group (p is less than 0.05). Average daily gain for the trial group was 0.777+-0.009 kg, which was by 12 % more than for the control group pigs (p is less than 0.05). Feed conversion in the trial group was 2.928 kg, but in the control group - 3.129 kg, which was by 6.4% higher than in the trial group. Gastric microflora analyses showed that use of phytoadditive reduced mould colony forming units (CFU) amount in the trial group decreased by 24 times. Duodenum microflora analyses showed that use of phytoadditive reduced mould CFU amount by 25%, yeast CFU amount by 34%, Escherichia coli mesophilic and termophilic forms CFU by 16.3% compared to the control. A lactic acid bacterium CFU in the trial group was 2.5 times higher compared to the control. Rectum microflora analyses showed that use of phytoadditive reduced mould CFU amount by 31.6%, yeast CFU amount - by 62%, Escherichia coli mesophilic and termophilic forms by 57 % and 15.6 % respectively. Lactic acid bacteria CFU amount in 1 g of sample in the trial group increased by 5.1 times.

Udder secretion samples from mastitic and healthy udders were examined at the Department of Veterinary Medicine of the LUA Research Centre "Sigra". In total, 117 samples from 117 cows were investigated. Somatic cell count was recorded for cows with clinical and subclinical infections, and uninfected cows. The mean somatic cell counts for cows with clinical and subclinical mastitis were 1 825 250+-417 697 cells ml*[-1) and 967 866+-75 796 cells ml*[-1), respectively. For healthy cows the mean somatic cell count was 87 666+-15 384 cells ml*[-1). Gram-positive microorganisms from the genera Micrococcus, Staphylococcus, Streptococcus, and Corynebacterium, and gram-negative microorganisms from the genera Enterobacter, Klebsiella, Salmonella, Escheria and Pseudomonas were isolated from samples from mastitic quarters.