Quality parameters for alpaca (Vicugna pacos) semen are affected by semen collection procedure

Artificial insemination (AI) is poorly developed in camelids owing to the difficulty in collecting high quality semen and the highly viscous nature of the semen. Semen collected by artificial vagina (AV) is often of low quality and must be improved before any further development of AI technology can occur. The present study investigated the effects of adding a cervix-like stricture to the AV, presence of females, collecting semen into Androhep, skim-milk or Tris diluents, and catalase supplementation (0, 100, 200 or 600 units/ml) of Tris diluent on alpaca semen quality parameters. The addition of a cervix-like stricture increased mating length (p < 0.05), whilst the presence of females during semen collection did not improve semen quality parameters (p > 0.05). Collection of semen into Tris diluent improved sperm motility (58.0 +/- 11.9%) compared with the control (34.0 +/- 10.8%; p < 0.05), Androhep (33.5 +/- 10.7%) and skim-milk diluents (28.2 +/- 10.4%). Semen viscosity was reduced by collection into Androhep (4.6 +/- 1.7 mm) and skim-milk diluents (3.6 +/- 1.3 mm) compared with Tris diluent (5.7 +/- 2.1 mm) and no collection medium (9.3 +/- 3.5 mm; p < 0.05). Tris diluent supplemented with 100, 200 or 600 units/ml catalase increased semen viscosity (5.0 +/- 3.2 and 4.9 +/- 3.2 mm). Collection of alpaca semen by AV into Tris diluent increased semen quality facilitating further development of AI technology in alpacas.