Sperm loss using different artificial vaginas in rams

The objective of the present study was to evaluate the effect of certain factors on sperm loss during ram semen collection, using an artificial vagina (AV). The factors analyzed were the effect of the male (8 rams), length of the artificial vagina (short versus long), order of the ejaculate (first versus second ejaculate) and lubrication technique (with or without lube). An observational study from a data set containing 55 semen collections from the 8 rams of different breeds (Montadale, Suffolk, Hamphshire, Polypay) were evaluated during the breeding season using a multiple regression statistical analysis over a period of 10 weeks. The results did not show any differences between rams, order of the ejaculate or the use of lubrication on sperm loss. The two types of artificial vaginas however showed significant differences in the percentage sperm loss (P <0.001). The total ejaculate volume (collection tube volume+liner and cone recovery volume) and sperm concentration/ml (x10⁹) were similar when using the two types of artificial vaginas. The total ejaculate volume recorded for the short artificial vagina was 1.5±0.4ml and for the long artificial vagina was 1.3±0.6ml. The concentration of the ejaculate was 2.7±0.6x10⁹ sperm/ml for the short artificial vagina and 2.9±0.7x10⁹ sperm/ml for the long artificial vagina. The volume of semen in the collection tube using the short artificial vagina was 1.3±0.4ml, compared to the 0.7±0.5ml for the long artificial vagina (P <0.001). The percentage of sperm loss from the short artificial vagina (12.9±5.9%) was significantly lower than when using the long artificial vagina (50.8±13.9%; P <0.001). From this study, it may be concluded that the type of artificial vagina affects the sperm loss; with the shorter AV recording a lower sperm loss. No effects were detected between rams, order of the ejaculate or the use of lubrication on sperm loss. From the results obtained the use of the short artificial vagina can be recommended.