Optimization of the summer microclimate in pig housing using an evaporative cooling system and its effect on the physiological condition and productivity of pigs and piglets

Abstract

use of an evaporative cooling system during the hot season in central Ukraine and its effect on the physiological state, well-being, adaptive properties, reproductive performance of Danish sows, and the growth of their piglets. F1 sows of the Bridgers maternal line, inseminated with the semen of Danish Duroc boars, were used for the study. During farrowing and lactation, sows were housed in rooms with negative pressure ventilation provided by two exhaust fans and supply valves at the end of the section. In the control room, only negative ventilation was used without additional cooling, while in the experimental group, high-pressure nozzles were used to reduce the air temperature, spraying water mist over the supply valves. It was found that the use of an evaporative cooling system reduced the air temperature in the room by 3.1–4.5 °C (or 7–16 %) compared to a similar room without irrigation. At the same time, it led to an increase in relative humidity by 10.9–16.0 % and in air velocity by 0.02–0.05 m/s (or 13–19 %), which indicates a significant improvement in microclimate parameters in summer for keeping sows and piglets. The use of an evaporative cooling system in the pigsty significantly improved the physiological condition of sows. This was manifested in a decrease in the heat-humidity index, a decrease in skin temperature, and a significant decrease in respiratory rate, which contributed to a 15–16 % increase in feed intake and an 11.8 % reduc-tion in live weight loss, and contributed to a 6–8 % increase in sow milk production, which indicates more favorable conditions for maintaining the body's energy balance and is a prerequisite for preserving the reproductive perfor-mance and high productivity of animals in subsequent cycles. It was found that the use of an evaporative cooling system reduced the proportion of stillborn piglets by 1.13 %, increased the average weight of a single piglet at weaning by 7.9 %, and increased the total weight of the litter by 9.3 %. contributed to an 8.0 % increase in the growth rate of suckling piglets, a 9.2 % improvement in absolute and 6.76 % relative gains, as well as a 10.9 % increase in absolute and 12.1 % increase in average daily gains of piglets in the litter, a 2.3–3.1 % increase in the complex indices of reproductive quality of sows. At the same time, feed conversion remained virtually unchanged, and the need for pre-starter feed for young animals decreased by 12–14 %. The results confirm the feasibility of using evaporative cooling systems in piggeries to increase productivity and improve animal welfare.