Welfare of recently weaned piglets transported on unpaved roads: the effect of age and the use of straw bedding

Abstract

This study evaluated the physiological responses of piglets weaned at three different ages and transported immediately over unpaved roads with and without the use of straw bedding in the transport vehicle. The study included 270 hybrid piglets born of York–Landrace dams and Pietrain sires. The piglets were weaned and then transported at 8 days old (n = 90), 15 days old (n = 90) or 22 days old (n = 90). The duration of each trip, from the time the transport vehicle left the original site until its arrival at the destination (site 2) on the same farm, was 1 h. The piglets in each one of the three groups were divided into two subgroups: (1) transported over unpaved roads with straw bedding; (2) transported over unpaved roads without straw bedding. Three repetitions were performed for each experimental condition. To assess physiological responses to the stress caused by transport, blood samples were taken as soon as the piglets arrived at site 2. The blood variables evaluated were: pH, haematocrit (%), glucose (mg/dL), electrolytes (Na+, K+ and Ca2+) (mmol/L), lactate levels (mg/dL), partial pressures of carbon dioxide (pCO2) and oxygen (pO2) (mm Hg), bicarbonate (HCO3–), and total carbon dioxide (TCO2C). Piglets that were weaned at 8 and 15 days of age and then transported without straw bedding were found to be more susceptible to metabolic, acid–base, hydric, and gas exchange imbalances (P < 0.05). Blood concentrations of pO2, Na+, K+, Ca2+ and pH were not affected by transport in piglets weaned at 22 days of age in vehicles using straw bedding. Hence, we conclude that regardless of age and trip conditions, the transport of recently weaned piglets constitutes a stressful situation, because just 1 h of transport time was sufficient to cause imbalances in their physiological blood indicators.