If the bull is good and the heifers are in good shape and cycling there is no reason that you shouldn't get 95+%. However, a bull likely won't get them all bred in one cycle. With AI the success rate can be extremely high or extremely low. It depends on a number of factors including how well one heat detects, proper technique, proper placement, etc. There is no reason that a good experienced AIer shouldn't get 75% on the first cycle. Realize that it takes more labor to AI than to run a bull with the heifers. Many people will agree that the added genetic improvement from AI is worth the extra time and effort. I personally would AI heifers the first cycle or even two and then use a cleanup bull.
For first service conceptions it probably runs about the same. Remember that in the tradtional 45 day breeding season that give the tech or the bull 2 bites at the apple. I usually run close to 90% first service and 100% with a second service. This year I ran 94% but that is the exception. Based on the palp results the bull ran about 75% but he only got one shot at them too.
breesding heifers in true heat your conception rate should be 80%.an then you should get the rest bred on the 2nd heat.an if 1 is open ship or put her with a bull.because with AI your only using a 42 to 56 day breeding season.