Article citation info: (*) Tekst artykułu w polskiej wersji językowej dostępny w elektronicznym wydaniu kwartalnika na stronie www.ein.org.pl Chłopek Z, BiedrZyCki J, LAsoCki J, WóJCik p. Assessment of the impact of dynamic states of an internal combustion engine on its operational properties. eksploatacja i Niezawodnosc -Maintenance and reliability 2015; 17 (1)

Our aim was to map the performance of local (native) dairy cattle breeds in Austria, Switzerland, Poland, and Sweden with regard to production, fertility, longevity, and health-associated traits and to compare them with commercial (modern) breeds. For this purpose, we analyzed test-day records (July 1, 2011, to June 30, 2014 and treatment records (Austria, Sweden) of cows managed on organic farms. We performed country-wise comparisons of 123,415 lactations from Original Braunvieh (OB) and Grey Cattle (AL) with Braunvieh (BV; Brown Swiss blood >60%) in Switzerland; AL with BV (Brown Swiss blood >50%) in Austria; Polish Black and White (ZB), Polish Red and White (ZR), and Polish Red (RP) with Polish Holstein Friesian (PHF) in Poland; and Swedish Red (SRB) with Swedish Holstein (SH) in Sweden. Average milk yields were substantially lower for local compared with commercial breeds in all countries; differences ranged from 750 kg (Sweden) to 1,822 kg (Austria), albeit on very different average levels. Local breeds showed a longer productive lifetime by 0.64, 0.83, 1.42, and 0.20 lactations in Switzerland, Austria, Poland, and Sweden, respectively, again on very different levels in each country. Regarding fertility traits, calving interval was shorter in local than in commercial breeds by 13 (Sweden), 14 (Switzerland), and 20 d (Austria, Poland). Insemination index was lower in certain local breeds by 0.15 (Switzerland), 0.14 (Austria), 0.21 (Poland), and 0.13 (Sweden). Several local breeds showed a lower proportion of cows with >100,000 somatic cells/mL. This was the case in Switzerland (OB 24.2%; BV 35.8%), Austria (AL 25.3%; BV 36.9%), and Sweden (SRB 42.4%; SH 43.4%). In contrast, the respective proportion in Poland exceeded 82% in all breeds except the commercial PHF (76.1%). In Sweden, lactations with veterinary treatments were considerably less prevalent in SRB (15.6%) than in SH (21.7%). In Austria, breeds differed only in treatments for udder disorders, which favored AL. In conclusion, the markedly lower milk yields of local breeds are partly counterbalanced by (somewhat inconsistent) advantages in longevity, fertility, and health traits across 4 European countries. This indicates that the robustness of local breeds can contribute to improved sustainability of organic dairy systems.

This study aimed to identify organic dairy major farm types (MFTs) in seven European countries, describe these MFTs in an open research database and assess central characteristics of the MFTs. This was conducted in a three-step procedure including (1) Identification of organic MFTs in seven European countries:

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A novel approach to modelling of motor vehicle operation by employing special test cycles threated as realizations of the stochastic process of vehicle velocity is presented. The families of test cycles were designed to simulate driving conditions in street congestion, urban, extra-urban, and high-speed traffic. The data necessary for the development of test cycles was obtained in the empirical investigations conducted in real road traffic. The recorded velocity time-histories were analysed in the time, frequency, and process value domains. Fragments of the velocity vs. time curves, representative for the considered driving conditions, were selected to design test cycles. The statistical examination of those test cycles demonstrated that individual process realizations are similar to each other and to all the process realizations recorded during the empirical tests.

Abstract. This study was conducted on a sample of 2237 Polish Holstein-Friesian cows. The aim was to estimate the effect of selected environmental factors on the level of urea in cow's milk and on its genetic parameters, i.e. the heritability coefficients, and genetic correlation with other selected traits of milk production. The present study has revealed the existence of a highly significant influence of herd, year of calving, parity, lactation phase, and milk performance level on the urea content in cow's milk. A high urea level in milk was detected in samples collected from older animals, both during the winter season and the middle phase of lactation (101-200 days).The heritability estimates were generally at a low level, particularly in terms of milk yield (0.183) and urea content (0.152-0.159), which may indicate the dominant role of the environment in shaping them. Relatively low values of genetic correlation (−0.097-0.140) between the urea content and other traits suggest that improvement of milk yield and its composition modify the urea level in milk only to a small degree.

The aim of the study was to analyse the effect of milking frequency during the first month after first calving on milk yield and milking parameters of the cows over the remainder of the first lactation and in subsequent lactations. The study was performed in 25 automatic milking system (AMS) herds located in Poland. The animal material under study was classified into one of five groups based on average daily milking frequency in the first month after calving (MFF): MFF1less than 2 times, MFF2between 2 and 2.5 times, MFF3between 2.5 and 3 times, MFF4between 3 and 3.5 times, MFF5between 3.5 and 4 times per day. Using a multivariate analysis of variance, statistical analysis showed that most of the studied factors and the interactions between them had a highly significant effect on the analysed milk yield and milking traits. The cows whose average milking frequency during the first month was lower than two, were culled in large numbers from the herd during the first lactation. The highest proportion of cows culled after the first lactation was noted in group MFF1 (68.47%) and the lowest in group MFF5 (35.29%), with the culling level after the first lactation averaging 48.59% for all the groups under analysis. The present study showed that the initial milking frequency of primiparous cows is particularly important under AMS. Therefore, farmers should give particular attention to the cows that are unwilling to visit the milking robot during that period.

This paper presents the algorithm for on-line adaptive Kalman filtering of sensor signals with unknown signal to noise ratio. A first order spectrum of a pure signal and white Gaussian measurement noise have been assumed. The results of the performance tests of the algorithm as well as the design methodology of the adaptive filter are given.