Effects of Treadmill Exercise on Respiratory Moisture Losses in Goats of Different Breeds

Changes in respiration rate (RR), rectal temperature (RT), respiratory moisture loss (RML), packed cell volume (PCV) and haemoglobin (Hb) were monitored in 2 adults female goats each of the Saanen (S) and Toggenburg (T) breeds during 60 min of exercise (walking at 3 km/h) on a moving-belt treadmill on each of 6 alternate days. A significant $time{\times}breed$ interaction was observed for RR; mean values in Sand T after 60 min of exercise were 130 and 223 /min ($p{\leq}0.01$). The observed time x breed interaction for RT indicated that S was less stressed by exercise than T; mean values after 60 min exercise were 40.4 and $40.8^{\circ}C$ respectively ($p{\leq}0.01$). For RML, the $day{\times}breed$ interaction ($p{\leq}0.001$) indicated that while S had higher values on day 1, thereafter the values for T were higher. The $time{\times}breed$ interaction for RML/breath indicated that values for T declined more rapidly (from 9.4 to 3.1 mgjbreath) than those for S (from 8.3 to 4.1 mgjbreath; ($p{\leq}0.01$). PCV declined during exercise ($p{\leq}0.05$) by 5.5 percentage points. The exercise imposed was stressful in that it led to increases in RR, RT and RML. S was most tolerant of exercise in that it recorded lower values of RT. The fact that the RML/breath was higher during exercies in S apparently allowed it to compensate for a lower RR. Despite higher RR and RML, T also had a higher RT, suggesting either higher muscular heat production during exercise in that breed, or higher sweating losses in S.