Seminal collection, seminal characteristics and pattern of ejaculation in llamas.

Semen was collected from 10/10 llamas during 26/30 (87%) collection attempts using an artificial vagina mounted inside a surrogate female. For the 26 semen collections, the duration of copulation (mount to dismount) with the artificial vagina was 31.7 +/- 12.0 min (mean +/- SD). Seminal pH was 8.1 +/- 1.1, and seminal volume per collection was 3.0 +/- 1.9 ml. Sperm concentration per collection was 1.0 +/- 0.8 x 10(6) sperm/ml, total number of spermatozoa was 2.9 +/- 3.1 x 10(6), total sperm motility was 23.7 +/- 20.0%, and the percentage of morphologically normal spermatozoa was 39.7 +/- 18.5%. Morphologically abnormal spermatozoa were categorized according to abnormal heads (20.1 +/- 19.9%), tail-less heads (8.7 +/- 8.9%), abnormal acrosomes (12.9 +/- 12.4%), abnormal midpieces (1.0 +/- 3.7%), cytoplasmic droplets (11.1 +/- 12.4%), and abnormal tails (6.6 +/- 12.0%). There were 0.3 +/- 0.3 million motile, morphologically normal spermatozoa per collection: less than 1000 during the first 5 min of copulation, 0.01 +/- 0.01 x 10(6) between 5 and 10 min of copulation, 0.04 +/- 0.08 x 10(6) between 10 and 15 min of copulation, 0.09 +/- 0.21 x 10(6) between 15 and 20 min of copulation, and 0.15 +/- 0.28 x 10(6) between 20 min and the end of copulation.