Normal Breeding Habits – Sheep

Normal Breeding Habits – Does StatusMeanRange Estrous (d) Estrus (hr) Ovulation (hr) Gestation (d)

Normal Breeding Habits – Billy StatusMeanRange Sperm production (b) Ejaculate volume (ml) Concentration (b/ml)

Puberty First estrusvs. First Ovulation Foster, D. L., 1994

Pubertal Transition LH pulses are present, but frequency is low During puberty, estradiol’s inhibition on GnRH decreases High frequency rhythm of GnRH is then expressed This leads to the follicular phase and the 1 st LH surge occurs Animal then ovulates Foster D.L., 1994

ProductionOptimum stage score Breeding3 – 4 Early - Mid Gestation2.5 – 4 Lambing (singles) Lambing (twins)3.5 – 4 Weaning2 or higher

Estrous Cycle PGF 2α Ovulation

Some Goats are Short Day Breeders Percent Daylight June Percent Ewes in Estrous Daylight Ewes in estrous

DARK light Pineal Gland Hypothalamus Pituitary Melatonin GnRH FSH LH To ovary