ENDOCRINE REACTIONS OF BULLS IN A METABOL IC STRESS TEST

Five AI-bulls (5.5-6 years of age) fitted with permanent vena cava or aorta abdominalis canulae were subjected to an one week lasting food r eduction used as a metabolic stress test. Frequent bleedings were perf ormed every 30 minutes for 10 hour periods from 5 days prior to until 35 days after start of the challenge. Reproductive and metabolic hormo nes (LH, testosterone, growth hormone, insulin and insulin like growth factor-I) were determined by radio-immunoassays.