Antibiotic resistance of Staphylococcus is increasing worldwide. New antibiotics are used in big amounts in the meat production more and more. As a zoonosis, Staphylococcus aureus (S. aureus) is found in various species of animals and people, especially in those, who are working on commercial swine farms and slaughterhouses. The aim of the study was to find out the occurrence of S. aureus in different age groups of pigs on commercial swine farms in Latvia. Microbiological samples (n=702) including nasal, rectal, milk and air samples were collected during October 2013 from three closed farms of different sizes and several age groups of pigs and investigated with microbiological standard methods. S. aureus was found in all swine farms. The occurrence of S. aureus in Latvian pig farms was 41% and the highest occurrence of S. aureus was among 3-3.5 month old piglets. S. aureus was 1.8 times more frequently found in nasal than in rectal samples, and only in 28.38% of pigs S. aureus was in both - nasal and rectal samples. S. aureus was found also in sow milk in 13% of samples and in 3 samples of air (n=23).

The objective of this article is to assess farm efficiency and productivity change in specialised large farms located in the region of Mazowsze and Podlasie during the years 2014 − 2016. For this, we used the non-parametric Data Envelopment Analysis (DEA) method and Malmquist index. Calculations were performed for three types of large farms classified as: field crop, pig and dairy. The study shows that mean technical efficiency of large field crop, pig and dairy farms amounted to 80, 75 and 70%, respectively. Technical inefficiency of field crop farms come mainly from scale efficiency, while of pig and dairy farms equally from pure technical and scale efficiency. It shows that inefficient management practices had an impact on farm performance. Therefore, in order to increase competitiveness of farms, an improvement of management practices is required. In the studied period the share of farms operating under increasing return was as follows: 67, 72, and 81%, respectively for field crops, pig and dairy farms. The improvement of efficiency of those farms could be achieved by increasing their size. The results indicate that 8% of field crops, 12% of dairy and 16% of large pig farms were operating under decreasing scale efficiency, which means that those farms were operating above the optimal scale. The increase in their efficiency could be achieved through size reduction. In dairy farms the average annual productivity growth of 2% was recorded. In pig farms the productivity reduction of 5.4% was observed. It was the result of a decrease in technological efficiency.