Successful semen collection from Capercaillie (Tetrao urogallus L.) kept in an aviary system

Abstract

We tested the feasibility of obtaining ejaculates from Capercaillie (Tetrao urogallus L.) kept under aviary conditions. A total of 9 individuals in their first (n = 4), fifth (n = 3) or sixth (n = 2) reproductive season were raised in floor pens in absence (1-year old males) or presence (5 and 6-year old males) of contemporary females and attempted to semen collections using the massage technique. Among the 9 males tested, successful ejaculations were observed more frequently in older (90%) than young males (50%). The following semen characteristics of ejaculates were observed: mean volume, 25µl in young vs. 41µl in older males; sperm concentration, 470 x106ml-1 vs. 1133 x 106ml-1; sperm viability (eosin-nigrosin test), 92.7% vs. 94.6%; morphologically normal sperm, 66.5% vs. 73.2%, for young and older males respectively. Overall, semen quality expressed as the Sperm Quality Factor reached a value of 10.5 in young vs. 33.8 in older males. These observations confirm the feasibility of performing successful semen collections in captive Capercaillie, a pre-requisite for the development of artificial insemination for the purpose of gene banking and to optimize the reproductive performance in this endangered species. It is also interesting that one-year-old Capercaillie can produce semen, however its quantity and quality is lower comparing to the older males.