Management of the female stimulus during semen collection and its association with libido re-establishment and semen characteristics of goats

Abstract

The effect of management of the female stimulus during semen collection and its association with libido re-establishment and the semen characteristics of sexually mature goats was evaluated. Eight 2-yr-old bucks were individually subjected to 12 weekly trials in which one of the following three treatments was applied alternately. In treatment one, each male performed two ejaculations on an estrus-induced, restrained doe and semen was collected with an artificial vagina (AV). In treatment two, males were collected as in the former treatment, but a different doe served as the stimulus female for the second ejaculation. In treatment three, two restrained does were present while collecting each buck, allowing males to choose which female to mount and serve in each of the two collections. Number of mounts before first ejaculation and reaction times (period from introduction of the ram to the test arena to his first ejaculation) were similar among treatments (P > 0.05). A significant (P < 0.05) decrease was found for number of mounts performed before achieving the second ejaculation and for latency between ejaculations in the third treatment. No differences (P > 0.05) were found for semen volume (0.8+/-0.03, 1.0+/-0.03, and 0.9+/-0.02 mL) or sperm concentration (4.4+/-0.15, 4.6+/-0.13, and 4.4+/-0.86 spermatozoa/mL) among the three treatments or between the first and second collection. However, a trend to decrease volume and concentration was observed. It was concluded that the simultaneous presence of two females while bucks are collected reduced the number of mounts performed before the second ejaculation and the latency between ejaculations.

Effect of exposing rams to a female stimulus before semen collection on ram libido and semen quality1

“…Most of the work to date on sexual stimulation in small ruminants has focused on restraining the male before semen collection or changing the female stimulus during repeated semen collection. This has been reported to be successful in goats through reducing reaction time (Prado et al, 2002(Prado et al, , 2003Silvestre et al, 2004) and increasing sperm output (Prado et al, 2003). In sheep, Thiery and Signoret (1978) demonstrated a shorter sexual reaction time in rams by changing the female stimulus, whereas Lezama et al, (2003) found no effect of changing the female stimulus on semen characteristics or interejaculation interval.…”

Semen evaluation in the chamois of Abruzzi (Rupicapra pyrenaica ornata)

“…Other semen parameters values reported in bibliography in small ruminants were: volume 0.7-2 ml, concentration 2-5 × 10 9 spermatozoa/ml, motility 70-90% and a sperm abnormalities percentage 5-15% (Mann and Lutwac-Mann, 1981;Chemineau, 1986;Chemineau et al, 1991;Roca et al, 1992;Prado et al, 2002).…”

Study of correlation between reaction time and refractory period (as indices of libido) with semen characteristics in ArkharMerino×Moghani and Baluchi×Moghani rams

“…The reactions are considered by two criterions: i) Reaction time; measured as the amount of time between the first contact with the teaser ewe and the first false mount with the penis erected (Hoflack et al, 2006). ii) Refractory period; measured as the time taken between first ejaculate till the second false mount for second serving (Prado et al 2002). Each ram was allowed to mount with the stimulus ewe and following the time was recorded for the reaction time and then the refractory period.…”