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<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.

The chemical composition of goat milk, especially fatty acid profile is recently renewed due to the role of monosaturated and polyunsaturated fatty acids in human nutrition. These nutrients are important to analyse in connection with the different breeds receiving the same breeding and feed. The aim of this study was to analyse goat milk fatty acid profile in relation to different breeds. Specimens for fatty acid analyses were collected from individual animals of breeds like Latvian Native (n=5), Saanen (n=5), and crossbreeds (n=5). Bulk milk samples (n=5) were also taken for milk quality testing and fatty acid range determination. Fat content was analysed according to ISO 1211:2011 and fatty acids were measured with the chromatographic method. Protein, lactose, casein and urea concentration was analysed according to ISO 13366-2:2007 and somatic cell count to ISO 9622/IDF141:2013.The highest fat concentration was determined in crossbreed milk samples (3.81 g 100 gE−1) and the lowest (2.96g 100 gE−1) in the Latvian Native breed goat milk samples. The highest butyric acid (0.12 g 100 gE−1) and caproic acid (0.12 g 100 gE−1) concentration was established in Saanen goat milk samples. Compared to other breeds, the milk of the Latvian Native breed goats is characterised by a higher capric acid (0.20 g 100 gE−1) concentration, while a higher concentration of total unsaturated and monounsaturated fatty acids was detected in the samples of crossbreed goat milk. The average fatty acid composition of bulk milk samples was 68% for saturated fatty acids, 23% for monosaturated fatty acids and 4.3% for polyunsaturated fatty acids. In analysed goat milk samples, fatty acids showed the characteristic fatty acid profile of goat milk.