Reproductive and Related Disorders on Dairy Farms with Different Levels of Welfare Quality

In this paper reproductive results of six dairy cows farms with total of 766 (farm 1 – 107; farm 2 –175; farm 3 – 49; farm 4 – 400; farm 5 –20 and farm 6 – 11 milking cows) with different system of rearing and welfare level were analyzed. A dairy cow reproductive efficiency is a key factor for milk production - impaired reproductive performance is a major cause of reduced production in dairy industry. Welfare and reproductive disorders data were collected by questionnaire regarding criteria of Animal Need Index (ANI – Bartussek et al., 2000) and compared by multidimensional criteria of total discriminating effect. Possibility of movement, lighting and air quality in the accommodation facility, type and quality of floor, possibility of social contacts with other cows and interaction of stockman with cattle were compared and analysed in respect of farm welfare. In respect to the welfare level of lowest ranked farm (farm 6), farms 1, 2, 3, 4, 5 and 6 were ranked as 4th, 2nd, 1st, 5th, 3rd, and 6th, respectively, but in respect to the reproductive and related disorders occurrence rate lowest ranked farm (farm 4), farms 1, 2, 3, 4, 5 and 6 were ranked as 1st, 4th, 2nd, 6th, 5th and 3rd. Discrepancy derives from the fact that reproduction data were collected for a year, while welfare assessment describes reached level in on particular moment of time, not covering all potential causes of reproductive disorders. Reduced reproductive success would seem promising as information about poor farm welfare, although good results often are not related to good welfare. Nevertheless, assessed welfare protection level provides important information about herd health and potential reproduction problems, pointing out that there are many opportunities for improving the quality of the welfare of dairy cows, mostly through improving the housing conditions of dairy cows

Dispersion of Waves in Relativistic Plasmas with Isotropic Particle Distributions

The dispersion laws of Langmuir and transverse waves are calculated in the relativistic non-magnetized formalism for several isotropic particle distributions: thermal, power-law, relativistic Lorentzian $\kappa,$ and hybrid $\beta$. For Langmuir waves the parameters of superluminal undamped, subluminal damped principal and higher modes are determined for a range of distribution parameters. The undamped and principal damped modes are found to match smoothly. Principal damped and second damped modes are found not to match smoothly. The presence of maximum wavenumber is discovered above that no longitudinal modes formally exist. The higher damped modes are discovered to be qualitatively different for thermal and certain non-thermal distributions. Consistently with the known results, the Landau damping is calculated to be stronger for non-thermal power-law-like distributions. The dispersion law is obtained for the single undamped transverse mode. The analytic results for the simplest distributions are provided.Comment: 8 pages, 12 figures, accepted by Physics of Plasma

Coexistence of orbital and quantum critical magnetoresistance in FeSe1−x_{1-x}Sx_{x}

The recent discovery of a non-magnetic nematic quantum critical point (QCP) in the iron chalcogenide family FeSe$_{1-x}$S$_{x}$ has raised the prospect of investigating, in isolation, the role of nematicity on the electronic properties of correlated metals. Here we report a detailed study of the normal state transverse magnetoresistance (MR) in FeSe$_{1-x}$S$_{x}$ for a series of S concentrations spanning the nematic QCP. For all temperatures and \textit{x}-values studied, the MR can be decomposed into two distinct components: one that varies quadratically in magnetic field strength $\mu_{0}\textit{H}$ and one that follows precisely the quadrature scaling form recently reported in metals at or close to a QCP and characterized by a \textit{H}-linear MR over an extended field range. The two components evolve systematically with both temperature and S-substitution in a manner that is determined by their proximity to the nematic QCP. This study thus reveals unambiguously the coexistence of two independent charge sectors in a quantum critical system. Moreover, the quantum critical component of the MR is found to be less sensitive to disorder than the quadratic (orbital) MR, suggesting that detection of the latter in previous MR studies of metals near a QCP may have been obscured.Comment: 19 pages (including Supplemental Material), 12 figure

In-flight calibration of STEREO-B/WAVES antenna system

The STEREO/WAVES (SWAVES) experiment on board the two STEREO spacecraft (Solar Terrestrial Relations Observatory) launched on 25 October 2006 is dedicated to the measurement of the radio spectrum at frequencies between a few kilohertz and 16 MHz. The SWAVES antenna system consists of 6 m long orthogonal monopoles designed to measure the electric component of the radio waves. With this configuration direction finding of radio sources and polarimetry (analysis of the polarization state) of incident radio waves is possible. For the evaluation of the SWAVES data the receiving properties of the antennas, distorted by the radiation coupling with the spacecraft body and other onboard devices, have to be known accurately. In the present context, these properties are described by the antenna effective length vectors. We present the results of an in-flight calibration of the SWAVES antennas using the observations of the nonthermal terrestrial auroral kilometric radiation (AKR) during STEREO roll maneuvers in an early stage of the mission. A least squares method combined with a genetic algorithm was applied to find the effective length vectors of the STEREO Behind (STEREO-B)/WAVES antennas in a quasi-static frequency range ($L_{antenna} \ll \lambda_{wave}$) which fit best to the model and observed AKR intensity profiles. The obtained results confirm the former SWAVES antenna analysis by rheometry and numerical simulations. A final set of antenna parameters is recommended as a basis for evaluations of the SWAVES data

Strategy for Sustainable Development and Utilization of Sheep and Goat Resources in Serbia

The aims of this study were to determine the status of small ruminant production in Serbia and to provide projections for their sustainable use with optimal strategy of genetic improvement of sheep and goats in the future. For sustainable sheep and goat production, it is necessary to know a number of biological, technological, organizational and market factors. Number of sheep in Serbia during the past two decades fell by about 20%.  This  country grows more than 1.7 million sheep. In terms of breed structures, most of the populations are indigenous Pramenka sheep (80%), while the remaining 20% are Tsigai, Merinolandschaf, Ile de France, Pirot improved, Mis sheep, and other less important populations, as well as the crossbreed with foreign and domestic sheep. Interest of goat rearing is constantly increasing in last years for 20-30%.  In regard to the breed structure, the least represented are goats of Alpine breed – approx. 2- 3%, White Serbian goat - 15%, different types of crosses – approx. 35% same as goats of low land Balkan type, and approx. 12% of high land Balkan type. Strategy of sheep and goat breeding programs in Serbia is focused on the improvement of indigenous breeds, because they are less demanding, and most importantly, the input is lower and their products have higher quality. Keywords: sheep; goat; sustainable; resources; meat; mil

Litters Health Status and Growth Parameters in the Sows Feeding Diets Supplemented with Probiotic Actisaf Sc 47® within Pregnancy Or Lactation

The aim of this study was to investigate the effect of supplementing standard diets for pregnant and lactating sows with live yeast culture (Saccharomyces cerevisiae) on their health status, as well as the health status and growth parameters of their litters during lactation. A total of 120 sows were divided into three groups: the first group was fed diets supplemented with probiotics during pregnancy (G+P, n=40), the second group was fed these diets during lactation (L+P, n=40), and the third group was the control group which was not fed diets supplemented with probiotics (C, n = 40). During the lactation period, a significantly (p<0.01) smaller proportion of probiotic treated sows (G+P=7.5%, L+P=12.5%) manifested clinical signs of the uterus and/or the udder disease in comparison with the control sows (22.5%). The incidence of infectious diarrhea in the nursing piglets was significantly (p<0.05) lower in the treated sows (12.5%) compared to the control sows (27.5 %). The average number of weaned piglets per litter (p/l) and average litter weight at weaning (lw) (G+P=11.6 p/l and 103.6 kg lw, L+P=11.1 p/l and 102.8 kg lw, C=10 p/l and 79 kg lw) were significantly higher (p<0.01 or p<0.05) in sows treated with probiotic compared to the control sows. These results clearly show that the use of probiotic significantly improves the health status of sows and nursing piglets, as well as the piglets growth parameters

Karakterizacija prevlake 316L nanete postupkom plazma navarivanja

Parts of industrial machines and structures are often exposed to the action of aggressive environments, which in a short period of time can provoke the loss of their integrity. It is well known that for extending the service life against erosion and corrosion, protection of the exposed structure zone by coating is frequently used. Various application methods of protective coatings are applied, and the most common are welding and thermal spraying processes. The aim of this study was characterization of coatings made of stainless steel 316L, widely used in chemical and petrochemical industries. The coating was applied on a structural steel S235JR by plasma transferred arc using powder as a filler material. Due to a number of advantages, the plasma transferred arc (PTA) surfacing process has found significant usages in the field of surface protection. This paper presents results of hardness measurements in characteristic zones of the coating and the base material, as well as microstructural characterization of coatings using optical and scanning electron microscopy. Results of EDS analysis of the coating and hardness measurements indicated that a relatively high dilution (26.1 %) of the base material (BM) and the filler material (FM) occurred in a very narrow zone above the fusion line, and thus did not significantly affect the chemical composition of the rest of the coating. Also, erosion resistance tests of coatings were performed by changing the basic functional parameters that is the impact angle and the speed of erodent particles. It was observed that the erosion resistance of the coating material decreases approximately linearly with the increase of the particle speed. Also, with the increase of the impact angle of the erodent (up to 45 °), the mass loss of the coating material is increased.Delovi mašina i konstrukcija su tokom rada izloženi delovanju agresivne radne sredine koja u kratkom vremenskom periodu može da naruši njihov integritet. U zavisnosti od radnih uslova, površina materijala može da bude izložena raznim mehanizmima oštećenja, od kojih se izdvajaju eroziona i koroziona oštećenja. Produžetak radnog veka ugroženih zona mašinskih konstrukcija moguće je izvesti različitim postupcima nanošenja zaštitnih prevlaka, a najčešće su to različiti postupci navarivanja i metalizacije. Cilj ovog rada je karakterizacija prevlake izrađene od nerđajućeg čelika klase 316L, koja je našla široku primenu u hemijskoj i petrohemijskoj industriji, nanete plazma postupkom navarivanja korišćenjem dodatnog materijala u obliku praha, na konstrukcioni čelik S235JR. U radu je izvršeno merenje tvrdoće u karakterističnim zonama prevlake i osnovnog materijala, kao i mikrostrukturna karakterizacija prevlake na optičkom i skenirajućem elektronskom mikroskopu. Takođe, izvršeno je eroziono ispitivanje prevlake promenom parametara ispitivanja, pre svega ugla nastrujavanja i brzine čestica erodenta

A Multilevel DC to Three-Phase AC Architecture for Photovoltaic Power Plants

This paper presents a photovoltaic (PV) inverter architecture composed of stackable dc to three-phase ac converter blocks. Several such blocks, each containing a converter power stage and controls, are connected in series on their ac sides to obtain transformerless medium-voltage ac interfaces for PV power plants. The series-connected structure is made possible by a quadruple active bridge dc-dc converter that provides isolation between the PV input and each of the three ac-side phases within each block. Furthermore, since incoming PV power is transferred as constant balanced three-phase ac power, instantaneous input-output power balance bypasses the need for bulk energy storage. To streamline implementation and maximize system scalability and resilience, decentralized block-level controllers accomplish dc-link voltage regulation, maximum power point tracking, and ac-side power sharing without centralized means. The proposed architecture is validated by simulations of a PV string to medium-voltage ac system consisting of six blocks and on a proof-of-concept hardware prototype that consists of three cascaded converter blocks.</p

Spectral Analysis of Solar Radio Type III Bursts from 20 kHz to 410 MHz

We present the statistical analysis of the spectral response of solar radio type III bursts over the wide frequency range between 20 kHz and 410 MHz. For this purpose, we have used observations that were carried out using both spaced-based (Wind/Waves) and ground-based (Nançay Decameter Array and Nançay Radioheliograph) facilities. In order to compare the flux densities observed by the different instruments, we have carefully calibrated the data and displayed them in solar flux units. The main result of our study is that type III bursts, in the metric to hectometric wavelength range, statistically exhibit a clear maximum of their median radio flux density around 2 MHz. Although this result was already reported by inspecting the spectral profiles of type III bursts in the frequency range 20 kHz–20 MHz, our study extends such analysis for the first time to metric radio frequencies (i.e., from 20 kHz to 410 MHz) and confirms the maximum spectral response around 2 MHz. In addition, using a simple empirical model we show that the median radio flux S of the studied data set obeys the polynomial form Y = 0.04X3 − 1.63X2 + 16.30X − 41.24, with $X=\mathrm{ln}({F}_{\mathrm{MHz}})$ and with $Y=\mathrm{ln}({S}_{\mathrm{SFU}})$. Using the Sittler and Guhathakurtha model for coronal streamers, we have found that the maximum of radio power therefore falls in the range 4 to 10 R⊙, depending on whether the type III emissions are assumed to be at the fundamental or the harmonic