This work summarizes the results from cervical artificial insemination of 2026 multiparous Rasa Aragonesa ewes. The influence of: 1) period of the year, 2) interval from last lambing to insemination, on the reproductive performance and body condition score of these ewes has been studied, as soon as the influence of: 3) the length of progestagen treatment on reproductive performance of ewes. Ewes were treated with FGA sponges for 12, 13 or 14 days, and 480 I.U. of PMSG at sponge withdrawal. Cervical insemination was carried out 56±1 hours after sponge withdrawal with fresh semen kept at 15°C. Sperm motility score and viability were higher than 4 and 75%. respectively. Thirty‑eight inseminated ewes were excluded for the study in base of the negative observations recorded by the inseminator. Fertility of these ewes was lower than the remaining ones (13 vs. 48%; P<0.05). Fertility was similar in ewes inseminated during the three first half‑year period (57.4, 53.6 and 5.4%, respectively ) while was significantly lower in the second half of 1995 (33.1 %; P<0.05 ). This effect could be due to the lower body condition score of females in that period in comparison to the previous ones (2.6 vs 2.9, 2.9 and 3.0; P<0.01). Body condition score was significantly lowered in ewes with intervals from lambing to insemination shorter than 60 days (range from 40 to 55 days), fertility was also 10 points lower in these ewes. The length of sponge treatment did not influence fertility or prolificacy. It is concluded that special attention must be paid to the stale of the ewes to be cervically inseminated in order to improve reproductive results in these ewes.
Esta web usa cookies para ofrecer sus servicios. Al seguir navegando en la web acepta el uso que se hace de las cookies. Pulse aceptar para dejar de ver el mensaje. Más información sobre Cookies