TABLE 61-4.

Reproductive Characteristics of Giraffids9, 10, 38, 40

Parameter	Giraffe	Okapi
Karyotype (2n)	30	44, 45, or 4652
Puberty, age (years)	Female at 3–4	Females at 2.5
	Male at 4–5	Males at 2–4
Estrus cycle (days)	14–15	15–16
Luteal phase	8	11
Follicular phase	6	5
Duration of copulation	Few seconds	Few seconds
Gestation	420–468 days	414–491 days
Pregnancy determination	Urinary/fecal PdG	Urinary/fecal PdG
Placentation	Cotyledonary placentation	Cotyledonary placentation
Urinary pregnanediol-3-glucuronide (PdG), nanogram per milliliter (ng/mL)
Nongravid:
Follicular	3.6 ± 7 ng PdG/mg Cr	1.9 ± 0.1 ng PdG/mg Cr
Luteal	30.9 ± 1.7 ng PdG/mg Cr	27.2 ± 3.9 ng PdG/mg Cr
Gravid	Persistent luteal levels	Persistent luteal levels
	>250 ng PdG/mg Cr in late gestation	With levels >100 ng PdG/mg Cr
Semen volume	4–6 mL	Unknown