Effects of physical stress on serum enzymes and other blood constituents in sheep.

In connection with transfer of sheep from the lowland near Oslo to mountain pastures at an altitude of 1,200 m above sea level, investigations were carried out in 37 animals to study the effect of physical stress on serum enzymes and other blood constituents. The sheep were adult ewes and lambs. About half of the animals had been accustomed to outdoor life on pasture for more than one month, while the others were moved directly from indoor feeding. Blood was collected before departure, after six hrs. of long-distance transportation by lorry, and after three hrs. of subsequent continuous herding on foot. The following blood components were determined: Aspartate aminotransferase (AspAT = GOT), alanine aminotransferase (A1AT = GPT), α-hydroxybutyrate dehydrogenase (HBD), total lactate dehydrogenase (LDH), LDH isoenzymes, alkaline phosphatase, calcium, inorganic phosphorus, magnesium, blood sugar, total serum proteins, and haemoglobin. In summary, it may be said that the lambs reacted with greater changes of the blood components than adult animals, and that untrained, indoor fed lambs were distinctly more sensitive than those taken from pasture. The “indoor” lambs showed a statistical significant increase from the initial values in AspAT, HBD, total LDH, the isoenzymes LDH and LDH, and blood sugar. Significantly decreased values were recorded in Ga, P, Mg, and total serum protein. Some of these changes, as in Mg and P, were most pronounced after transportation, while elevations of serum enzyme levels continued to increase during the subsequent herding. Based upon the shift in LDH isoenzyme distribution towards a more cathodically dominated pattern it is supposed that the main origin of increased serum enzyme activity was skeletal muscle.