Time of testicular descent

At birth

Testicular size in adults

2 × 4 cm (alpacas)

3 × 6 cm (llamas)

Start of puberty

Androgen production starts between 8 and 14 months of age, but penile frenulum does not break down until 18–24 months

Normal semen characteristics

Milky to translucent, viscous

Normal volume of single ejaculate

0.3–0.7 mL

Percentage of sperm motility/ejaculate

40%–80% (alpaca)

60%–80% (llama)

Sperm concentration in ejaculate

30 to 170 ×10³/mm³ (alpacas)

60 to 188 × 10³/mm³ (llamas)

Percentage of live sperm/ejaculate

65%–90% (alpacas)

81%–90% (llamas)