Influence of diet and evaporative cooling on the heat production and the performance of the sow in the summer

• Grant number: 09/16800-0
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2010
• End date: July 31, 2012
• Field of knowledge: Agronomical Sciences - Agricultural Engineering - Rural Buildings and Ambience
• Principal Investigator: Irenilza de Alencar Naas
• Grantee: Irenilza de Alencar Naas
• Host Institution: Faculdade de Engenharia Agrícola (FEAGRI). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The experiment will be carried out in a swine commercial farm. It will be used 80 sows of the breed DanBred individually reared in pens inside the farrowing building. This research has the hypothesis of the use of evaporative cooling associated to the use of a special diet using electrolytic balance may enhance the heat exchange in favor of the sows during the exposition to high ambient temperature, and consequently minimize the negative effects on their performance. The experiment will start in the day the piglets are born, and will continue during the lactation period until the sows show estrus. The experimental design is of random block with four factorial treatments (2 X 2) and 20 repetitions per treatment. The treatments will be two cooling systems (natural ventilation and evaporative cooling) and two diets (natural electrolytic balance of 160 mEq kg-1 and adjusted balance of 260 mEq kg-1). For registering ambient data (temperature and relative humidity) four data loggers will be used in the rearing farrowing housing and the data will be registered every 60 min. Air velocity will be registered using an anemometer and light intensity using a luxmeter. Respiratory frequency will be recorded along with the measurements of surface temperature which will be recorded using a thermal camera and the rectal temperature will be registered using a clinical thermometer. Blood and urine sampling will be made in the beginning and at the end of the experiment. Drinking water quality, flow and temperature will also be evaluated. Thermal comfort index (THI) and the sensible heat exchange (conduction, convection and radiant) and latent heat exchange will be calculated. The variables related to performance will be recorded and evaluated (feed consumption and corporal condition of sows) and the reproductive data (weight and mortality of piglets at birth and at weaning). Estrus lag time will also be evaluated. SAS software will be used for statistical analysis. (AU)