Mortality of Broiler Chickens During Summer Fattening Periods Affected by Microclimatic Conditions

Mortality of chickens during two summer fattening periods L1 and L2 in commonly used halls for chicken fattening in Slovakia have been evaluated in this paper. Effect of microclimatic conditions in housing area on recorded mortality has been analysed. Mortality was assessed in six halls, microclimate parameters and surface temperatures were continually measured only in one of the middle halls. It was documented that high mortality occurred during summer in the last phase (P3) of fattening period due to sudden hot weather waves. Daily mortality rate varied up to 447 birds in evaluated hall 3. During the last third of both fattening periods, it was significantly higher than during the first two phases (PL1 = 0.0036; PL2 = 1.4·10−6). Differences among halls were insignificant (PL1 = 0.614; PL2 = 0.413). In L1, average daily temperatures went beyond the recommended temperatures from 21st to 31st day. During L2, it was from 29th to 31st day and from 36th to 38th. The extra high mortality occurred in L1 on 31st day (447 birds) and during L2 on 36th day (88 birds), 37th day (96 birds) and 38th day (155 birds). High differential temperatures have been recorded and uninterrupted time periods (6 hours or more) with temperature higher than 30 °C and/or the relative humidity (RH) exceeding 70% were occurred during these days. In order to eliminate effect of sudden hot weather waves, modern digitally controlled microclimate regulation technologies (heat pumps, floor cooling, etc.) can be used, supported by data obtained from detailed microclimate analysis documented in this paper

Verification of Thermo-Technical Characteristics of Selected Floor Constructions for Dairy Cows (Pilot Study)

The purpose of this study was to theoretically and practically investigate the thermo-technical properties of two bedding surface materials under real farm conditions during the hot summer period. The study was focused on the research of cubicles with water mattresses and straw bedding for dairy cows. The results of thermal-technical calculations showed that straw belongs to the category of warm floors, the thermal effusivity value of cubicle with straw is b = 173.55 W·s1/2·m−2·K−1; the heat transfer coefficient is U = 0.36 W·m−2·K−1. Water mattress belongs to the category of cold floors with the thermal effusivity value b = 572.46 W·s1/2·m−2·K−1 and the heat transfer coefficient U = 4.504 W·m−2·K−1. On the basis of calculations, the results showed that U was 12.5 higher for water mattresses than for straw, and b was 3.3 times higher for water mattresses than for straw. Based on thermographic measurements under field conditions of dairy farm, it was observed that the surface temperature of the water mattresses after one hour of lying was lower by 4.95 ±1.88 °C in comparison to chopped straw. In practice, suitability of the material structure of water mattresses was verified on the basis of physical properties for summer period