Abstract
The serum growth hormone (BGH) and free fatty acid (FFA) concentrations of large groups
of calves (male and female ranging in age from 8 to 14 days and from 3 to 6 months
old), bulls, oxen, heifers and cows under normal conditions were compared with the
serum BGH and FFA values of corresponding large groups of animals under stress conditions.
Stress was caused by transport, as it routinely occurs, and was further reinforced
by a stay of several hours in unfamiliar surroundings. Stress provokes a significant
increase in serum FFA in all groups and induced a significant decrease in serum BGH
in all groups, with the exception of the non-pregnant heifers.
The male and female calves which were 8 to 14 days old, had significantly higher
BGH levels than the older animals. The female calves from 3 to 6 months of age, and
the heifers had significantly lower BGH levels than the cows.
The males had higher serum BGH values than the females, but a significant difference
could be demonstrated only between the male and female calves of both age-groups.
The oxen, which were 1 to 3 years old, had significantly higher BGH levels than the
non-pregnant heifers of the same age.
It appeared that gestation had no influence on the serum BGH and FFA levels of both
heifers and cows.
Key words
Stress - Age - Sex - Gestation - Serum Growth Hormone - Serum Free Fatty Acids - Cattle
