Effect of hot weather on microclimatic parameters in stable for sows

Abstract. The objective of this work was to evaluate the effect of hot summer weather on microclimatic parameters in the stable for mated and pregnant sows without and with using of evaporative cooling. Sows were housed in strawless gestation crates. Exhaust cross-ventilation was used in the stable. The high-pressure system was used for evaporative cooling. Pipeline with nozzles were installed outside the building on the wall above the inlet openings. Cooling effect was evaluated by comparing the measured parameters of the microclimate in the section with cooling (C) and without cooling (N) and in the outdoor environment. Evaporative cooling system was activated since noon to 6.00 p.m. Measurements were carried out from 1.00 to 6.00 p.m. Universal device ALMEMO 2290-4 and anemometer Testo 435 were used for recording of measured parameters. Basic statistic parameters were calculated, data were analysed by One-Way AOV by the STATISTIX, version 9.0. During the evaluated summer period (48 h), the outdoor air temperature ranged from 21.5 to 34.8°C and relative air humidity ranged from 32.2 to 84.2%. Indoor air temperature in the section N ranged from 23.4 to 33.3°C and in the section C from 24.0 to 31.1°C. The relative humidity ranged from 35.7 to 76.4% and from 56.0 to 74.4% in sections N and C. The temperatures 32°C and higher were registered only in the section without cooling. At an average outdoor air temperature 31.54°C (during the application of water spraying), the temperature of air in the section C (29.96°C) was lower by 2.92°C than in the section N (32.88°C, P<0.001) and lower by 1.58°C than the outdoor temperature (P<0.001). Relative air humidity in section C was higher by 18.52% than in section N (67.17% vs. 48.65%, P<0.001). The average air flow velocity in animal zone in section N was 0.113 m/s and in section C it was 0.175 m/s (P>0.05). The average outdoor wind speed was higher (1.226 m/s, P<0.001). Efficiency of evaluated evaporative cooling system was moderate, because the nozzles were placed outdoors and only part of the humidified and cooled air was drawn into the building through inlet openings, and also because the indoor air flow velocity was low

EFFECT OF DIFFERENT COOLING SYSTEMS ON LYING TIME OF DAIRY COWS IN CUBICLES WITH SEPARATED MANURE SOLIDS BEDDING

The aim of this study was to investigate the changes of lying time and other behaviour manifestations of dairy cows during usage of different cooling systems of animals. Alternative hypothesis was presumption, that the lying time of cows in lying cubicles with applied two different cooling systems are indifferent. The sprinkling system was used to animal cooling in group S in summer time. In group SV was disposable sprinkling system and diagonally rotated ventilators. Activities and the rest of animals were evaluated in 10 minute intervals using a camera system for 24 hours. Data obtained was tested by nonparametric Kruskal-Wallis one-way ANOVA and multiple comparison test for detecting of significant differences in the behaviors between groups of cows. There was found positive effect of animal enhanced cooling using sprinkling system with increased air movement by ventilators. It reflected in significant prolongation of whole lying time and shortening of time, when animals were standing. It resulted from final values of investigated behaviour manifestations of dairy cattle within 24 hour period that animals in group SV with sprinklers and ventilators lay in stalls longer than in group S with sprinklers, but without ventilators (10.76 h*d-1*cow-1 vs. 7.71 h*d-1*cow-1, P0.001). The total time spent by lying in stalls and in alley represented in group SV 11.31 h*d-1*cow-1, and in group S 10.22 h*d-1*cow-1. Animals, from group S without ventilators, which were less cooled, were significantly more lying down in alleys (2.52 h*d-1*cow-1 vs. 0.56 h*d-1*cow-1, P0.001)

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