Transport stress in horses: Effects of two different distances

This study compares the effects of 2 journeys of different lengths (50 km and 200 km) on horses. The first journey lasted about 1 hour, the second about 3 hours. Twelve Standardbred horses were used for the test. Blood samples were collected and analyzed (packed cells volume [PCV], cortisol, aspartate transaminase, alanine transaminase, creatine kinase, lactate dehydrogenase, creatinine, glucose, triglycerides, cholesterol, blood urea nitrogen, calcium, phosphorus, chlorine, total proteins, albumin, and alkaline phosphatase), and heart rate (HR), respiratory rate, and temperature were measured at 5 different experimental times: at rest, at loading, at unloading, and at 2 and 4 hours after return from the journey. Behavior was recorded by direct observation of loading and unloading, within the vehicle, and 2 and 4 hours after arrival in a new stall. The same parameters were recorded at the same times (excluding loading and unloading) in a control group of horses that had not travelled. All the data were analyzed using a repeated measures analysis (analysis of variance).Loading always caused an increase of HR and PCV. The different journey lengths produced significant increases in serum glucose, cortisol concentration, PCV, and HR. Serum cortisol concentrations after short transport were considerably higher than values registered at rest and after long transport. The long journey caused an increase of creatine kinase 2 hours after return. On arrival in the new stalls, the horses that had travelled sniffed less and snorted later than the control group. They ate immediately and more quickly, and those that had travelled 200 km also showed more interest in water than those that travelled for 50 km and the control group. The other behaviors, including exploratory, rest, and play activities, were concentrated in the second 2-hour observation period when the horses tended to feed less. The present trial showed that adaptation to a new stall could be facilitated by offering horses food and fresh water when they arrive, and that for horses that must make a 3-hour journey before a race, it would be better to arrive at their destination at least 4 hours before beginning physical activity.