Although our systems and society may function differently I believe I may be able to give a quick run down of how I go about sourcing my Dairy X calves, what is economical for me, and what I look for in a calf. When I think about the rotating Beefies I carry to slaughter, my main goal is to keep costs down, and to grow a top quality product. I buy the calves direct from the farm at 95KG wean weight, this usually costs me 300NZD an animal, this cost includes a 7in1 vac shot, selenium/b12 booster, leptospirosis vac and a first round drench.
I don't know if things are different in USA, but worming in NZD is referred to as drenching. this also gets rid of other parasites such as scabies. in order to combat any resistance being formed by the parasite it is imperative to change the active chemical in your drench, this would usually follow a routine of a pour on, followed by an oral followed by a pour etc etc, this ensures the parasites that are not killed by the first drug are killed by the 2nd. We usually drench according to what feed the stock are going on to. but as a rule of thumb it is every 2 months if moving off and ontop crop or spring and late autumn if on a pasture exclusive diet.
I mainly use a Hereford X Friesian, I choose this mix for the hardiness and height of the friesian, and the quality and beef capacity of the hereford. Its important to note that not all cattle breeds are made the same! for example,
The Jersey breed has the benefits of having Black hooves (stronger than Friesians and less likely to suffer rot), High avg progeny( gets in calf easier than a Friesian) great milk fat to protein ratio, but suffers from lowered hardiness chronically, udder blowout and strep based throat infections, and lastly an increased metabolic risk on certain feeds and pastures. Each breed will have a grocery list of pros and cons, this is where you have to identify what will work within your system and stick to it. And contrary to popular belief, if I could find a Good Breeder I would take a pure Ayrshire over any X, hybrid vigour or not.
On the topic of Colostrum, I have never fed Colostrum past the 2nd day, the mother only produces true colostrum in the first 24 hours, this is due to the calf being born without a properly functioning immune system. every subsequent feed post that first 24 hours will have an increasingly reduced amount of functioning white cells within the milk and an increase in proteins, fats and calcium. What is MOST important for that calf past feeding colostrum is feeding roughage!! I used to feed straw to my calves straight away! it is important for the calves Rumen development to undergo a process called Rumen scratching, if the calf doesn't undergo this process the Rumen will not properly form and grow, this will give you problems down the line and decrease the overall hardiness of your animal. As the Milk bypasses the Rumen and is digested within the Abomesum ( a stomach that functions on acid like a humans) without any product moving through the calves rumen the calf will be at risk of scouring (diarrhoea) and losing precious nutrients.
I will leave a link to a slaughter chart I use to pick my dates, 2 years is a fine amount of time to wait, but I would definitely choose a date (summer is best) and plan to to give that animal as much quality feed leading up to slaughter to ensure you have good quality well finished Meat. one thing to also keep in mind is the enjoyment factor of rearing that animal, its not just meat at the end of the day, its 2 years of calculated effort leading to an income of highly nutritious Beef.
Sources : 6 Years Dairy Farm Experience
Slaughter Chart : https://www.grass-fed-solutions.com/beef-cattle-slaughter-weight.html
Pasture Based Info sheet on growth targets, with some discussion on drenching : https://beeflambnz.com/knowledge-hub/PDF/growing-cattle-fast-pasture#:~:text=In%20the%20fast%20growth%20path,at%2024%20months%20of%20age