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Identification of the Slovak traditional cheese “Parenica” microflora
227-239Views:232Numerous studies have demonstrated the higher accuracy, faster time-to-results and lower costs provided by MALDI Biotyper systems compared to classical methods. In this study, the culturable population of total count of bacteria, enterococci, coliforms bacteria, lactic acid bacteria (LAB) and microscopic fungi and yeasts from cow’s dairy products was identified using the MALDI-TOF MS Biotyper. Altogether, 50 samples of the Slovak cheese “Parenica” were examined. Total numbers of bacteria were cultured on Plate count agar at 37 °C for 24–48 h, aerobically; enterococci were cultured on Enterococcus selective agar at 37 °C for 24–48 h, aerobically; coliforms bacteria were cultured on Violet Red Bile lactose agar at 37 °C for 24–48 h, aerobically. The LAB were cultured on MRS (Main Rogosa agar), MSE and APT agar at 30 °C in microaerophilic conditions. The microscopic fungi and yeasts were cultured on Malt extract agar at 25 °C for 5 days, aerobically. Isolated strains (total 669) were subjected to identification by the MALDI-TOF MS. Among total count the identified bacteria mostly were Acinetobacter baumannii, Bacillus cereus, Micrococcus luteus and Staphylococcus warneri. Escherichia coli and Enterobacter cloacae were the most abundant coliform bacteria representatives identified. Coliform bacteria included Citrobacter, Hafnia and Klebsiella. Altogether three genera belonged to the LAB – Lactobacillus, Lactococcus and Leuconostoc were identified with Lactococcus lactis, Lactobacillus plantarum, Lactobacillus coryniformis, L. fructivorans and Leuconostoc mesenteroides were considered as the dominated LAB species in dairy products. Among yeasts, Kluyveromyces lactis, Candida zeylanoides and Yarrowia lipolytica were among the most isolated.
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The effect of feeding different glycerol sources on the performance of lactating sows
99-103Views:161Glycerol is a by-product of the biodiesel industry and it might be a good alternative to moderate the energy deficiency of sows during the lactation period. Preliminary experiments were carried out to test the effect of a powder, solid based “food grade” glycerol source with 72.9% glycerol content (Trial 1) and a liquid “feed grade” glycerol source with 86% glycerol content (Trial 2) on the performance of lactating sows and their litters. Trial 1 was conducted with 5 Hungarian Large White×Hungarian Landrace sows/treatment (313±24.9 kg) and Trial 2 with 12–12 DanAvl (323±17.0 kg) sows and their litters/treatment. Neither the solid, powder based glycerol (Trial 1), nor the liquid glycerol source (Trial 2) had significant effect on the feed intake, reduction in live weight and back-fat thickness, and weaning-tooestrus interval (p>0.05) of lactating sows. In Trial 2, on the 14th, 21st and 27th days of lactation the milk samples were collected and it was found that 50 kg/t glycerol decreased the protein content of milk samples (p<0.05). Glycerol supplementation had no effect on dry matter, fat, lactose content of milk samples (p>0.05). In Trial 2, no significant difference was found between control and experimental sow groups in triglyceride concentration of blood samples and in the activity of liver enzymes (ALT, AST, GGT; p>0.05), but the concentration of plasma glucose and cholesterol increased tendentiously (p<0.10).
Based on our preliminary results, it can be concluded that additional dose trials are needed to perform in order to study the effect of glycerol supplement on milk production and on metabolic processes of lactating sows.
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Impact of lameness on the milk production of ewes
5-7Views:114The aim of this study was assessing the impact of lameness on the milk production, somatic cells count and component of milk. We assess also impact of lameness on the order of entry into the milking parlour.
The experiment was carried at the farm, located in northern Slovakia. The farm keeps sheep Improved Valachian. Samples of milk were taken during two periods: May, July. It was taken 428 samples together. We recorded three groups by lameness- strong lame, slightly lame, non-lame ewes. We recorded also the order of entry of ewes into the milking parlour in milking row. The results were mathematically processed using the Microsoft Excel program and statistically evaluated by SAS.
We found significant statistical differences between months (P<0.0001) in all the above mentioned indicators. In July we recorded 26 ewes with slightly lameness and 18 ewes with strong lameness. Other ewes were non-lame. Non-lame sheep had in July the highest milk yield (356±148 ml) and the lowest decrease in milk yield from May to July (-206±131 ml) compared with slightly (317±116 ml, -223±163) and strong (319±122 ml, -219±151 ml) lame ewes. However, these differences were not statistically significant. We have not identified statistically significant differences between groups in somatic cells count (logxSCC for non-lame: 4.83±0.608 in ml, slightly lame: 4.76±0.653 in ml, strong lame 4.71±0.787 in ml). Milk composition (fat, proteins, lactose) nor changes in the composition of milk that occurred between May and July were not affected by lameness of ewes. But lameness in July affected the change the order of entry of ewes in the milking parlour in July compared with the order of entry recorded in May.
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Saccharomyces cerevisiae growth kinetics study dairy byproduct
169-172Views:167By guess, annual volume of milk whey is 185–190 million tons and this volume probably will increase next years. Whey has significant biochemical oxygen demand due to its high organic matter content so whey as sewage is one of the most pollutant by-products in the food industry. Apart from environmental pollution, benefit of several whey constituents for human health is another reason to utilize whey. Corn and potato, as well as the processing of milk in the food industry in large quantities of by-products generated by low cost, substantial quantities of starch and lactic acid, which are due to high biological oxygen demand are considered as hazardous waste. Some of them are destroyed sewage storage tanks, and those products are excellent substrates for the growth of microorganisms could be. The traditional nutrient solution optimization methods are solution and time-consuming and are not able to determine the real optimum because of the interaction of factors involved.
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Changes in the Composition of the Milk of Racka Sheep During Lactation
24-28Views:100We examined the changes in the composition of the milk of 36 Racka sheep during lactation. As milking of Racka sheep is not performed anywhere in the country, the test was restricted to the examination of milk components. However, quantity could not be measured. We analysed the fat, protein, lactose, carbamide and somatic cell count content of the milk from sampling. By means of correlation analysis, milk components were compared to the age of ewes, then the number of lactation days. With the advancing of the lactation and by analysing the milk components, we found differences between the two colour-variants of Racka sheep. Additional trials are required to decide whether the differences between the two colour-variants may be considered as constants, or can be attributable to the relatively small number of samples.