Phil Crome wrote:No offense, but you have got to be kidding. I respect the effort you're making, but there is absolutely no way the USDA should be paying for any of this. Rams that settle only 30% either by AI or natural means, then backup rams that are also sterile, then ewes that windup open anyway? Using rams for live cover immediately after collection doubtless affects conception, but is that accounted for in your experimental design?
I get that you need outside bloodlines, preferably ones with strong fertility traits. There has to be a better way of getting them than this. Aren't there any real sheep problems that need research.
Well first off the USDA isn't paying for the research except for the lab time and researchers time and they consider it important to work on. They no longer have any access to research flocks that are of more typical commercial sheep that are willing to work with them so we're it. We are not an ideal flock by any means but we offer the flock and all of our time and our facilities for free. Other research flocks that are around have been unwilling to do the record keeping and individual handling necessary for this type of research. If you don't like them spending time on a rare breed then step up and offer a more typical flock, with all the required record keeping with all the required labor at no charge that is within driving distance of the lab to reduce any travel or other expenses and I am sure they will take you up on it.
You are not understanding the protocol, probably because I didn't explain it well. We separated the ewes into 2 groups. half were bred via AI and half via live cover. In normal years, we get 95%+ pregnancy rates with over 75% of them on the first cycle with live cover rams with no sync or other interventions. This is only the second time I've ever had a ram that did not work well so I am not skilled in dealing with that. He was very young, he passed his pre-breeding semen checks so who knows what the issue was. It is very unusual for that to happen in Welsh Mountain sheep at all. Both the live cover and AI groups had backup rams put in but quite a bit later so we could be sure who the sire was. We also restricted the time the backups are in with the ewes to limit the lambing season. Keep in mind a more typical way to deal with breeding is a bank of rams not individual rams in with individual groups of ewes, especially as the backups. I need to know full pedigrees so I can't do it that way. Most folks also leave rams in a lot longer than we do. I only have backups in for 2 weeks, so at most one cycle. In our system a ewe only gets 2 chances to get pregnant, once with the primary ram and once with the backup ram. Total time exposed to rams in our flock is usually 4 or 5 weeks at most split up by a waiting period between primary and backup. I typically have primary rams in for 2-3 weeks, then 2 weeks with no ram and then a backup ram for 2 weeks. I also butcher out ewes who do not get pregnant by that system unless there is a really good reason why they did not get pregnant. So for this year of the open ewes, any who were in with the ram that failed to work will get looked at and may stick around if I find no other issues with them. All the rest will be slaughtered.
The AI group was AI'd per a very specific hour protocol based on the researchers trying to get publishable results that take current research being done in Norway and Ireland a bit further. Is it an ideal protocol, heck no, but it was done to answer some specific questions left open by previous research. The live cover ewes had the same sync protocol and the same rams as we used to collect semen and do AI to help eliminate ram issues.
None of our rams are well trained to collection at the AI. The rams who were used the year previously were much better, both in terms of collecting semen and in terms of overall performance both via AI and live cover. Without any intervention the older rams have a history of getting 100% of their ewes pregnant within 21 days. Other rams used in the experiment have been good breeders before as well although not 100% but we also tried a number of new or maiden rams because part of the question is what do we need to do to the rams to get them to work in this sort of program.
Other researchers spend a long time training and selecting rams. Private correspondence indicates that they eliminate up to 90% of the rams they try to use for AI for one reason or another. It's clear that training and selecting the rams is a big part of success that other places are seeing. Of course, they also have huge government sponsored flocks (as in thousands of sheep available with rams of all breeds and ages) and can spend months teaching the rams the collection procedure without stress before they ever try to get semen for their AI experiments. We did know that and had worked with the rams prior to the experiment but not as much as other countries do. That's something we are going to change for next year.
Hope that explains things a bit more.