Parámetros morfométricos del espermatozoide de alpaca (Vicugna pacos), obtenidos por tres métodos de colección

Abstract

Sperm morphology is essential in evaluating seminal quality and important for fertility prediction in breeding males. The aim of this study was to compare the morphometric parameters of alpaca sperm, collected using three methods of semen extraction, recovery of the vas deferens (DCD), electro ejaculation (EE) and vaginal aspira-tion (VA). The collection was made of 3 animals by each method. The mobility, concentration, vitality, mem-brane functionality and sperm morphometry parameters were determined in a computerized semen analysis kit – ISAS® CASA - Morph. For morphometric parameters, semen samples were processed with a Hemacolor® stain-ing kit and viewed under a phase-contrast microscope. For each sample, at least 200 sperm were captured at random, with an image resolution of 0.08 μm per pixel on the horizontal and vertical axes. The comparison of the morphometric parameters between the collection method and the animal was carried out using a random block design. Total motility was 16.27±11.96%, 14.68±11.21% and 12.44±7.27%; the sperm concentration of 247±186.70x106EPZ/mL, 67.92±67.92x106EPZ/mL and 100.32±56.13x106EPZ/mL, the vitality was 62.86 ±15.92%, 63±15.21% and 70.16±14.33% in sperm collected by DCD, EE and AV respectively. Regarding the morphometric parameters, a length of 5.49±0.43μm, 5.53±0.41μm and 5.75±0.53μm was found, area 14.30±2.00 μm2, 15.05±1.77 μm2 and 15.88±2.00 μm2, perimeter of 16.10±1.31μm, 17.11±1.20μm and 17.41 ± 1.43, width of 3.22±0.27μm, 3.30±0.32μm and 3.33±0.25μm and the acrosome percentage of 52.22±7.82μm, 49.52±7.47μm and 47.44±5.77μm in sperm collected by DCD, EE and AV respectively. The morphometric parameters of the size and shape of the sperm head and the intermediate piece showed significant statistical differences (p <0.01) between the collection methods and between the animals. In conclusion, the morphometric parameters of alpaca spermatozoa were influenced by collection method, and show variations between animals.