Your heifers weight should be 60% of the cow herd's. But, they should also be around 15 months of age, though a couple months plus or minus isn't going to hurt either.
A yearling bull, which is best used on heifers, can breed from 10 to 20 heifers in a breeding season.
A male intact bovine that is used for breeding cows and heifers.
Heifers getting serviced by a bull or through artificial insemination to get pregnant and give birth after 9 months of gestation.
The thing I'd like to know is what the "mix" part is in the "Holstein mix" equation. Is it Jersey, Guernsey, Hereford, Milking Shorthorn, Brown Swiss, Angus, Shorthorn, etc? And what type of bull are you looking for, a beef bull or dairy? That's the most important part you need to analyze before you make your bull purchasing decisions. For any heifers, you will need to look for a calving-ease bull. For most starting heifers, Jersey or Angus is probably the best for starters.
Breeding season for cows and heifers should be from 45 to 90 days long. Sixty days is considered optimum.
You can either buy one--off a local producer who sells such calves or from your local salebarn--or you can get one yourself by breeding an Angus cow with a Hereford bull (or a Hereford cow with an Angus bull). Even breeding a modern-type Simmental cow with an Angus bull (or vice versa) will get you a black-baldy calf.
Angus, Red Angus, Texas Longhorn, Hereford, Shorthorn, Red Poll, Devon, Galloway, or any other British breed that will put more muscle and growth in the calves but keep them small for the heifers to calve out.
Depends on the bull. Usually a bull can service up to 25 females in a single breeding period; others can breed 50 if they have high libido.
The best thing to do is to change bulls every three breeding seasons (over a 2 year-period) to avoid inbreeding (i.e., the bull breeding with his daughters). A heifer, from birth, takes around 15 months to reach sexual maturity before she is ready to be bred. Between that time, you can breed your cows once (before the bull's heifers are born), then a second time (when the bull's daughters are around 2 months of age), and finally a third time to the heifer's dams that they have since been weaned off of a few months ago (heifers should be around 10 months of age by the third breeding season) before selling him and purchasing another bull to breed that bull's daughters. You will have to do the math and lay out the generations to see when and how your breeding program will work.
It's best to leave him in for around 60 to 80 days to make sure he catches all of them.
The average weight of a purebred Angus bull, at maturity, is ~2500 pounds. This depends on his diet, genes, and general health. There are a lot of mature Angus bulls that can weigh well over 2500 lbs, and there are mature Angus bulls that will only weigh around 2000 lbs.
This depends on whether that bull has already reached puberty or not. Usually the safest time to start breeding a young bull to cows and heifers is when he's at least 10 months of age.