thanks for the responses.
To be a little more clear. From the start I really didn't feel it would make a difference putting a show bull on my herd or a bigger commercial bull. Here is the story of what got my mind thinking...
Well again its hard to answer some of these questions without knowing records on the cow herd, EPD's on your cattle, how youre trying to sell them (auction, private treaty, etc) and what goal you're shooting for. Just because a bull is a "show bull" does not necessarily mean he will be smaller than a commercial bull, unless the show bull you're using is a club calf type bull, which would not be good. The size difference you're referring to is the difference in breeds, a Charolais type bull is going to be bigger than an Angus bull no doubt, and you're headed in the somewhat right direction, because yes Charolais and other continental breeds will throw very framey calves, but they don't grade as well as British breeds or British/Continental crosses, and feeders don't like feeding them as much as British breeds because they aren't as efficient as British type or Brit/Cont cross cattle
In the other ear I'm being guided by the person who helped me buy and raise my show steers for all the years I used to show. He doesn't think it would make much of a difference at weaning time, but then again he wants me to make sure I'm doing what's best for me (or at least what I think is best for me and what is going to be most profitable) and does not argue that the elder man knows what he is talking about, considering he has been in the cattle business longer than most people have been alive.
Well, first off its not as easy as saying well this will or won't make a difference at weaning time, there are literally millions of factors that can play into profitabilty, what is your definition of profitability? Is it weaning a certain amount of lbs total of calves based on your cow numbers, is it having your cow herd pay for itself and nothing more? Or is it having each cow wean a calf thats half its bodyweight? Theres no way to just guess that a bull will sire high weaning weight calves, you can guess all you want, but one of the only more accurate ways to try and get these type of calves is to look at the EPD's of your bull. And keep in mind that weaning weight is not the cut and dry determining factor of good feeder calves, what about a bull that throws low birthweight calves or has a high calving ease? Is it more profitable to have all calves out alive, and make it to weaning and not have to pull 40% of them than it is to wean big calves but only wean 60% of them? Or what about having calves that are yield grade 1's and 2's and all of them grade Prime? It all depends on what your goals are as a producer and what you are looking for in terms of profitability, if it is purely high weaning weights you want than I suggest going to a large seedstock producer who sells 200-300 bulls a year to producers just like you, and who will have extensive records and EPD's on their bulls, heck a good commercial angus bull starts around $1500 and in a year or two a good commercial bull will have paid for itself in terms of increased profits from better calves.
Even better yet, and I don't know what your operation has in the way of working facilities, but the number one way a commercial cow calf producer can take advantage of better genetics is A.I. and if you're looking to improve your calves and the quality of the bulls you're using than A.I. is the way to go. Also look into horizontally integrated marketing programs such as those run by a local cattlemen's association, especially ones that include age and source verification.
Good luck, feel free to ask anymore questions, happy to answer them and see someone who is interested in improving the quality of their cattle