EFFECT OF UNDERNUTRITION ON GONADOTROPIN PROFILES IN NONPREGNANT, CYCLING GOATS

Gonadotrophin profiles were studied in does during an oestrous cycle i n which they were fed rations which provided maintenance or 25% of mai ntenance requirements, Undernutrition had no significant effect on bas al LH and FSH profiles, but was associated with a decrease in the numb er of goats exhibiting a preovulatory surge of gonadotrophins, reduced magnitude of the surge, and reduced incidence of ovulation, In a furt her experiment, intravaginal progestagen sponges were used to synchron ise oestrus in goats fed maintenance and restricted diets. A single in travenous injection of GnRH (13 mu g) was administered 12 days after s ponge removal. The magnitude of the surge of gonadotrophins following GnRH administration tended (P < 0.1) to be less in does on restricted feeding than in does on adequate nutrition. Short-term undernutrition appeared to decrease reproductive performance by interfering with gona dotrophin release.