Collection method, season and individual variation on seminal characteristics in the llama (Lama glama)

The objective of the present study was to evaluate the effect of semen collection method (electroejaculation “EE” as compared with the artificial vagina “AV”), the season (summer versus winter) and the male used on macroscopic and microscopic characteristics of ejaculates in llamas. A total of 110 ejaculates were collected from six males and 92 of them were analyzed. Ejaculate volume, concentration, total sperm and the following sperm characteristics were studied: motility, membrane function (HOS test), membrane integrity (CFDA/PI fluorochromes) and morphology. A mixed linear model, that considered season and collection method as the fixed variables and the male as the random variable, was used for the statistical analysis. Variability was found between males (p ≤ 0.05) when comparing the seminal characteristics. When considering the number of collections performed and the number of ejaculates discarded with each method, significant differences (p < 0.01) were found between collection methods (EE and AV), with EE having a greater proportion of successful semen collections. There were significant differences (p ≤ 0.05) between collection methods for volume, sperm motility and membrane function. Ejaculates obtained by EE have a greater volume, sperm motility, live spermatozoa and sperm with functional membranes. Comparison of semen variables between the two seasons indicated that sperm concentration and sperm abnormalities were different (p < 0.01). Ejaculates obtained during winter have greater sperm concentration and less sperm tail abnormalities than in summer. We conclude that semen variables have individual variation in llamas and are affected both by method of collection and season. The most desirable semen quality was obtained during winter using EE as the semen collection method.