I know the industry has said that 14 or 15 days is the standard. But we have found that a longer time frame worked great for us. I will explain.
Last year was our first year doing AI. We had inserted Cidrs into 3 does. The same time a friend did on his farm. When it came time for the 15 days, to pull the cidrs and inject PMSG, the weather was horrible. Very rainy and stormy for several days in a row. We ended up leaving the cidrs in for 19 days. So did the friend. We pulled the cidrs at 19 days and injected the PMSG and AI'd about 56 hours later. We were 100% successful on our first year. Our friend was 7 of 8 on his does..which was better than he had done on previous years.
We feel that leaving the cidrs in an extended time actually made it a better chance that the cidrs actually reset the does cycle. We feel that some does just aren't being reset in the standard 15 day time frame, but a few days longer will reset their cycle.
Just our findings. Hopefully this information will help some of you in the future.