Influence of Keeping and Milking of Cows on the Hygienic Quality of Milk

The quality and quantity of milk is significantly influenced by housing conditions, care and feeding of dairy animals. Hygienic correct milk can be obtained if the cows or other dairy cattle are kept in hygienic conditions. The aim of this study was to investigate the effect of housing conditions and milking of cows on the microbiological and chemical quality of milk. We examined six samples of bulk tank milk cows from 6 different farms from the Municipality of Podgorica, where cow milking is done by machines. Chemical parameters of milk - fat, protein, lactose, free fat dry matter and somatic cells were investigated on the device Combi-Foss (Foss Electric, Denmark), and the total number of bacteria on the appliance BactoScan. All obtained data were processed using modern variation statistics. Statistical parameters: mean value, standard deviation, maximum and minimum values, are calculated. In order to assess the hygienic conditions of keeping and milking of cows at these farms a certain building, microclimate and hygienic parameters were studied - by modified method of Hristov and Reljić (2009). Based on the established state, each test parameter is rated from 0 to 5 points. Average value of the fat content in bulk tank milk was 3.39 % - ranged from 2.92 % to 3.94 %, protein content 3.13% - ranged from 2.78 % to 3.65 %, lactose 4.27% - ranged from 4.14 % to 4.47%, the fat free dry substance 8.13 % - ranged from 7.75 % to 8.77 %. The value of the number of somatic cells in bulk tank milk at the first farm was 52000/mL, second 85000/mL, third 63000/mL, fourth 1920000/mL, fifth 1373000/mL and sixth 200000/mL. The total bacteria count in the bulk tank milk at the first farm amounted to 5000/mL, second 41000/mL, third 124000/mL, fourth 1002000/mL, fifth 467000/mL and sixth 31000/mL. Physical, microclimate and hygienic parameters of dairy cows housing are rated with good rating on farms 1, 2, 3, 4 and 6 and on the farm 5 with a sufficient rating. The fourth and fifth farms did not use disinfection of teats after milking and disinfection of milking machines. The fourth and fifth farm had significantly higher number of somatic cells in bulk tank milk. The fifth farm had significantly higher total number of bacteria/mL in bulk tank milk - compared to the number that is permitted under applicable regulations. This can be linked with inadequate building, microclimate and hygiene of cows and failing disinfection of the udder and milking machine after milking

The Effect of Supplementation on Selenium and Zinc Content in Blood and Milk of Dairy Cows

Milk is an important source of microelements for calves during the suckling period as well as in human nutrition. Concentration of trace elements in blood and their secretion via milk can significantly change depending on food intake and composition. Proper control of selenium and zinc content in blood and in milk can improve the status of these microelements, so that the occurrence of deficiency or excessive quantity due to their increased intake can be prevented. This paper presents the results of the study on the concentration of selenium and zinc in the blood and milk of diary cows whose rations have been supplemented by organic forms of selenium (0.2 mg/kg DM) and zinc (40 mg/kg DM) during the last ten days of dry period and early lactation. Supplemented cows in trial groups A and B achieved significatly higher concentrations of these microelements in blood (Se 186.70±8.50 µg/L vs. 118.80±7.05 µg/L), blood serum (Zn 1204.70±109.5 µg/L vs. 1095.40±130.2 µg/L) and milk (Se 57.30±8.05 vs. 21.30±4.60 µg/L; Zn 2893.90±120.15 µg/L vs. 1952.10±130.50 µg/L) on 60th day postpartum compared to non-supplemented control

Thionation of N-Methyl- and N-Unsubstituted Thiazolidine Enaminones

The potential of the directional non-bonded 1,5-type S···O interactions to initiate an incipient stage of an in situ rearrangement of N-unsubstituted thiazolidine enaminones to the functionalized 1,2-dithioles has been demonstrated. Spectral characteristics, as well as an X-ray structural analysis of the selected rearranged product, indicate that a dynamic interconversion occurs in a solution between the 1,2-dithiole and 3,3aλ⁴,4-trithia-1-azapentalene bicylic form. The lack of the rearrangement in the case of the N-methyl substituted enaminone precursor is attributed to an unfavorable methyl migration in the last reaction step

A Comparative Investigation of an in vitro and Clinical Test of the Bifidogenic Effect of an Infant Formula

The bifidogenic effect of an infant formula supplemented with inulin and fructooligosaccharides (4.0 g/l) was examined clinically and in vitro, and compared that of mature breast milk. In a 28-day clinical study, fecal samples of 21 infants, divided into two groups: one receiving the infant formula and the other breast milk, were microbiologically and biochemically examined. In the in vitro investigation, microbiological and biochemical changes in the infant formula and breast milk induced by the action of bifidobacteria isolated from infant feces were examined. There were no significant differences in the fecal numbers of lactobacilli, total aerobes, anaerobes or yeasts and fungi. In contrast, the bifidobacteria numbers in the stools increased significantly during the study in the infants receiving the supplemented formula. The comparative in vitro test showed that the bifidogenic effect was similar for infant formula and breast milk in terms of the number of bifidobacteria. Consumption of infant formula with added inulin and fructooligosaccharides stimulated the bifidogenic effect, both clinically and in vitro. The in vitro test can quickly and objectively determine the bifidogenic effect of infant formula and indicate their quality. However, a clinical test is necessary to determine the acceptance and biological value of infant formula

Structural Conformers of (1,3-Dithiol-2-ylidene)ethanethioamides: The Balance Between Thioamide Rotation and Preservation of Classical Sulfur-Sulfur Hypervalent Bonds

The reaction of N-(2-phthalimidoethyl)-N-alkylisopropylamines and S2Cl2 gave 4-N-(2-phthalimidoethyl)-N-alkylamino-5-chloro-1,2-dithiol-3-thiones that quantitatively cycloadded to dimethyl or diethyl acetylenedicarboxylate to give stable thioacid chlorides, which in turn reacted with one equivalent of aniline or a thiole to give thioanilides or a dithioester. Several compounds of this series showed atropisomers that were studied by a combination of dynamic NMR, simulation of the signals, conformational analysis by DFT methods, and single crystal X-ray diffraction, showing a good correlation between the theoretical calculations, the experimental values of energies, and the preferred conformations in the solid state. The steric hindering of the crowded substitution at the central amine group was found to be the reason for the presence of permanent atropisomers in this series of compounds and the cause of a unique disposition of the thioxo group at close-to-right angles with respect to the plane defined by the 1,3-dithiole ring in the dithiafulvene derivatives, thus breaking the sulfur–sulfur hypervalent bond that is always found in this kind of compounds.Ministerio de Economıá y Competitividad, Spain (Project CTQ2012- 31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1), and the European Commission, Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411

Quality of “urda” obtained after production of montenegrin semi-hard cheese

"Urda" cheese is one of the dairy products with a long tradition of production in mountainous areas in Montenegro. It is mainly used for its own use, fresh and unsalted, but can be kept for a longer period in “kaca” (vat) and consumed as a mature “urda”. Knowing the quality and technology of production of urda is significant regarding its nutritional and biological value, as well as in terms of its standardization, the preservation of traditional technology and the protection of geographic origin. Because of that, we examined the urda production technology in the artisanal conditions as well as the chemical composition of 14 urda samples from different production batches. Production of urda was done in a traditional manner with less modification. The results showed significant variations in the chemical composition of the tested samples. The mean value of dry matter content was 42.85%, fat content 21.74%, protein content 13.66%, salt content 2.67%, fat content in dry matter 50.77%, free fat dry matter content 21.11% and water content in free fat dry matter 49.67%. Due to significant statistical differences in the chemical parameters of investigated urda samples, it can be concluded that standardization of urda quality and technology has to be done

Least Squares Modeling of Voltage Harmonic Distortion Due to PC Cluster Operation

Regarding the possibility of harmonic generation, personal computers (PCs) are very significant within the category of non-linear low power loads. In modern distribution systems, the number of PCs simultaneously connected to distribution grid constantly increases. This PC clustering can negatively affect the quality of supply. The paper deals with mathematical modeling of the voltage total harmonic distortion (THDU) caused by operation of PC cluster. The proposed model is based on the power quality measurements carried out in a computer centre and computer simulations. It takes into account the THDU dependence on the PC cluster size and grid stiffness. Model parameters are derived in the least squares sense. The influences of cable cross-section and pre-existing THDU of the phase voltage are also discussed. The accuracy of the proposed model is confirmed by additional measurements performed in a commercial building