most firms are feeding very limited corn. It creates to much internal heat, for optimum embryo survival. Your ration would be likely low in all minerals with exception of perhaps calcium, and any hay over a month old has limited vits. I am not convinced that any hay,grain rations , has adequate vits, minerals, except during maintenance periods. Any other stage of production, those rations are decidedly lacking, in some area. Some recent work, suggests that mineral/vits mixed with salt, has limited Benefit, if mix is over a couple of weeks old. Many peeps , doing this work are using breeder vitamin pacs such as sure champ, vita ferm ect. I see a couple of places sell, products especially for this purpose. They run about .25 a day per ewe, so 60 days of that per ewe, will run you 15.00 per head. I am not advocating any, but a though vit/mineral/protein /energy ration , is imperative . I mix all rations on farm, and mix a ton or so of grain mix at a time. breeding and lactation are not times to scrimp. I am more prone to over supplement during those times, and use 3 different products to ensure high levels of vit,mineral supplementation. With 150 ewes and at times 300 or more on feed, fresh is not an issue here. Condition score should be at least 2.5 and more likely 3. This is not a time to scrimp on feed, or quality of feed. And time to achieve that is likely well before beginning cidr insertion. Any prebreeding vaccinations, must be done at least 30 days prior to cidr insertion,as well as deworming, feet trimming, and shearing.
ewes should be moved into the breeding gruop at least 30 days prior to and for at least 30 days after LAI. So that means at least 2 gruops of ewes , for at least 60 days. These ewes ,should be handled and stressed as little as possible, with other ewes. Ewes should be acclimated to working facility, before all of this begins. Ewes will be handled several times. at least 2 cidrs and 3 depending on protocal. ET ewes will be run through system many times. Catching one ,"behind a gate" ,or "running one around the pen" ,is not conducive a high rate of success.
Flushing ewes , is not an option for this. Skinny ewes do not work. They should be at the right condition , at least 30 days prior to ai. And taking those ewes home after AI, and kicking them out with the rest of the flock, is ill advised as well.
I would be contacting others in your area, who have a proven program in doing this, and do exactly , what your TECH says. Not what someone who heard, or what a friend of a friend of a friend, who knows someone, who did this.
Most Techs, have a protocal the works for them, and will be the best resource. I assume you must be thinking of breeding for fall lambs, so would be making sure all loose ends are tied up, very soon. As some one mentioned, A couple of firms have attractive pricing, right now.
I like to use proven rams in my choices, but others are infatuated with the pictures that young rams take. I have seen a lot of "young guns" take a good picture, and they 'aged" pretty bad. And again, depends on your ewes. If you got 3 or 4 K burning a hole in your pocket, a round of AI, will extinguish that fire ,pretty effectively.
good luck
And maybe your the guy, that knocks one out of the park, on your first turn at the plate. It does happen.