Post by serendipity on Aug 15, 2017 20:27:20 GMT -5
Has anyone ever heard of depositing semen in the vagina of sheep or goats instead of through the cervix? I found this study in an old issue of Wool & Wattles fall 2012 that showed similar success rates using the two methods. I didn't even know depositing in the vagina was an option.
AASRP-L QUESTION AND ANSWER -
Artificial Insemination of Sheep and
Goats in Sweden
Question:. What are the pregnancy rates in sheep using what we call here
“splash insemination”? Were these ewes synchronized or is this on natural
heats? Was this using frozen semen or fresh? And final question: is there a
breed difference in results? We have found good results using cervical AI
with fresh semen (up to 70%), but not with frozen. However if the semen
is frozen in increased concentration specifically for a cervical program results
improve.
Answer: Here in Sweden laparoscopic AI is not allowed for animal welfare
reasons. (One exception was made when we imported fertilized Dorper
ova). So our research (in cooperation with Norway) has been to compare
intravaginal AI with intracervical. There is no significant difference in
pregnancy result. Between 58 and 67% in different reports. So we now
teach the farmers intravaginal AI. We put a ram in a small pen, and when
the ewes are in heat they gather around the pen, only interested in the ram,
so the farmer can inseminate them intravaginally without even holding
them. It is done in a couple of seconds. The method is called “ a shot in
Wool&Wattles July-September 2012 9
the dark”. Usually the ewes are naturally synchronized with the ram effect.
Some figures I have: Frozen semen up to 67% pregnancies and fresh semen
56-63%. These lambing rates refer to one of the earlier papers that compared
two different deposition sites: Effect of vaginal and cervical deposition of
semen on the fertility of sheep inseminated with frozen-thawed semen.
Paulenz H, Söderquist L, Adnoy T, Nordstoga AB, Andersen Berg K., Vet
Rec. 2005 Mar 19;156(12):372-5. Some factors, such as breed, personal
experiences of AI, treatment of the animals etc. can influence the results.
Kalle Hammarberg, Hudiksval, Sweden
An abstract of this article was included in Wool & Wattles 33.3, 2005, and
is repeated here (editor):
Norwegian sheep flocks are relatively small (average of 52 adult animals) and
a cooperative breeding scheme moves rams between flocks belonging to the
same ‘ram circle’. Recent Norwegian restrictions on the movement of sheep
between flocks to control scrapie have caused a renewed interest in artificial
insemination, and farmers have been using AI on a do-it-yourself basis for
several years. Because liquid semen has only a 12 hour storage time, frozen
semen would be more practical. For this study 6 Norwegian crossbred
rams, 1.5 to 2.5 years old and with proven breeding value and fertility were
collected with an artificial vagina at the beginning of the November to
December breeding semen. Ejaculates were evaluated for semen quality and
diluted with a milk based extender, then frozen in 0.25 ml Minitub straws to
provide 200 x 106
spermatozoa per dose. Only straws from batches that had
at least 50% progressive motility post- thaw were approved for use. Farmers
on 10 different farms in western Norway inseminated 543 ewes themselves,
after attending an AI training course. Ewes were alternately inseminated
into the vagina (straight pipette advanced as far as possible into the vagina
without use of a speculum) or into the cervix (pipette with an eccentric
tip advanced 5 to 12 mm into the cervical canal with the aid of a vaginal
speculum and light source). Semen from a randomly different ram was used
for the next pair of inseminations on the farm. Natural estrus was detected
with a teaser ram twice a day and the ewes were inseminated 5 to 28, average
14 hours after detection of estrus. Cervical insemination resulted in a not
significantly higher 25-day nonreturn rate of 75.4% vs 71.3% for vaginal
insemination. The lambing rate (72.7% vs 67.4%) was significantly higher
for cervical insemination. Only one farmer had a statistically greater success
rate for cervical insemination. The lambing rate for each of the 6 rams used
varied from 58.5% to 78.3%. This suggests that selection of rams for AI
should include fertility after use of frozen semen. Ewes are already selected
for fertility in Norway
AASRP-L QUESTION AND ANSWER -
Artificial Insemination of Sheep and
Goats in Sweden
Question:. What are the pregnancy rates in sheep using what we call here
“splash insemination”? Were these ewes synchronized or is this on natural
heats? Was this using frozen semen or fresh? And final question: is there a
breed difference in results? We have found good results using cervical AI
with fresh semen (up to 70%), but not with frozen. However if the semen
is frozen in increased concentration specifically for a cervical program results
improve.
Answer: Here in Sweden laparoscopic AI is not allowed for animal welfare
reasons. (One exception was made when we imported fertilized Dorper
ova). So our research (in cooperation with Norway) has been to compare
intravaginal AI with intracervical. There is no significant difference in
pregnancy result. Between 58 and 67% in different reports. So we now
teach the farmers intravaginal AI. We put a ram in a small pen, and when
the ewes are in heat they gather around the pen, only interested in the ram,
so the farmer can inseminate them intravaginally without even holding
them. It is done in a couple of seconds. The method is called “ a shot in
Wool&Wattles July-September 2012 9
the dark”. Usually the ewes are naturally synchronized with the ram effect.
Some figures I have: Frozen semen up to 67% pregnancies and fresh semen
56-63%. These lambing rates refer to one of the earlier papers that compared
two different deposition sites: Effect of vaginal and cervical deposition of
semen on the fertility of sheep inseminated with frozen-thawed semen.
Paulenz H, Söderquist L, Adnoy T, Nordstoga AB, Andersen Berg K., Vet
Rec. 2005 Mar 19;156(12):372-5. Some factors, such as breed, personal
experiences of AI, treatment of the animals etc. can influence the results.
Kalle Hammarberg, Hudiksval, Sweden
An abstract of this article was included in Wool & Wattles 33.3, 2005, and
is repeated here (editor):
Norwegian sheep flocks are relatively small (average of 52 adult animals) and
a cooperative breeding scheme moves rams between flocks belonging to the
same ‘ram circle’. Recent Norwegian restrictions on the movement of sheep
between flocks to control scrapie have caused a renewed interest in artificial
insemination, and farmers have been using AI on a do-it-yourself basis for
several years. Because liquid semen has only a 12 hour storage time, frozen
semen would be more practical. For this study 6 Norwegian crossbred
rams, 1.5 to 2.5 years old and with proven breeding value and fertility were
collected with an artificial vagina at the beginning of the November to
December breeding semen. Ejaculates were evaluated for semen quality and
diluted with a milk based extender, then frozen in 0.25 ml Minitub straws to
provide 200 x 106
spermatozoa per dose. Only straws from batches that had
at least 50% progressive motility post- thaw were approved for use. Farmers
on 10 different farms in western Norway inseminated 543 ewes themselves,
after attending an AI training course. Ewes were alternately inseminated
into the vagina (straight pipette advanced as far as possible into the vagina
without use of a speculum) or into the cervix (pipette with an eccentric
tip advanced 5 to 12 mm into the cervical canal with the aid of a vaginal
speculum and light source). Semen from a randomly different ram was used
for the next pair of inseminations on the farm. Natural estrus was detected
with a teaser ram twice a day and the ewes were inseminated 5 to 28, average
14 hours after detection of estrus. Cervical insemination resulted in a not
significantly higher 25-day nonreturn rate of 75.4% vs 71.3% for vaginal
insemination. The lambing rate (72.7% vs 67.4%) was significantly higher
for cervical insemination. Only one farmer had a statistically greater success
rate for cervical insemination. The lambing rate for each of the 6 rams used
varied from 58.5% to 78.3%. This suggests that selection of rams for AI
should include fertility after use of frozen semen. Ewes are already selected
for fertility in Norway