Eficiência do molhamento da carga de leitões como atenuante do estresse térmico durante o manejo de transporte

Abstract

Inadequate planning of the piglet transportation operation can compromise animal welfare and cause production losses for the sector. This study investigated the hypothesis that wetting piglets during loading can increase the heat load and intensify animal stress due to air saturation in the internal environment of the load compartments. To this end, 14 commercial journeys with a fixed route of 97 km were monitored, 7 of which were subjected to the wetting protocol (CMOLHA) and 7 without wetting (SMOLHA). Rectal temperature (TR ºC), respiratory rate (FR breaths/min), orbital temperature (TO ºC), salivary cortisol (ng/mL), creatine kinase (UI/L) and lactate (mg/mL) were measured in 168 piglets (12/trip) after transportation. The volume of water used was measured from the start and end of the wetting protocol. Environmental parameters were recorded full-time by mini weather stations attached to the vehicle compartments. The data was subjected to basic descriptive statistics followed by Student's t-test at 5% significance (P<0.05). The average amount of water used in the CMOLHA was 2,700 ± 180 liters/trip, totaling an average value of 18,900 ± 180 liters over the 7 trips monitored. The results showed that the temperatures within the transport load did not differ (p>0.05), but there was a significant increase of 13% and 8.74kg/kj of dry air in the relative humidity and enthalpy of the CMOLHA. The piglets transported in the CMOLHA treatment had higher salivary cortisol levels (p<0.05). Under the conditions in which the research was carried out, the protocol of wetting the piglet load during the transportation stage proved to be inefficient in mitigating heat stress.