To be honest, you are asking a very wide question here, and we could all write long essays that may or may not help you with what you are trying to achieve. I think you would get better results either if you ask simpler, more direct questions and then left space for us to answer as to why we respond as we do, or if you said what a specific report was about that month, and then asked us for our opinion on the subject... There's no shortage of opinions in this place
Are you wanting to be in a position to advise customers on how to buy the cheapest meat for their business? I say meat as you are fairly specific about one question - what affects slaughter costs. That in itself is quite confusing. To me, slaughter costs are the costs the slaughter house charges me (eg £20 for a sheep).
If you are asking what I would charge someone for a dead pig from my farm, the answer would depend on what type and age pig they wanted, and what for. If they wanted pork prepared for a freezer from a 6 month old pig, then they'd pay somewhere around £250 for it. If they would like a fatter, older animal for charcuterie, then it may be £300. If the hotel down the road wants me to supply two pigs a week to them every week for a year, they'd probably get them (un butchered) for £160-£200 per pig depending on age.
Matters affecting the price of my meat include:
a) by the cost of feed and whether the product I am raising is part of our ordinary business or as a 'special' (ie if someone wants their pig fed on acorns and forage rather than concentrates and cider pressings, then they will need to pay for it)
b) by what I believe the customer will pay (hotel wants regular and local. he wants a photo on his wall showing that he knows where his pigs come from, but doesn't have the margins that a wealthy housewife from London has. His custom is bread and butter to my business and gives form to my year's pig plans. I therefore charge him less per kg than the family who want to visit the piglet, have photos and updates on how it is growing and decide they would like me to feed it the whey from their home made cheese).
c) which slaughterhouse we are using (the prices of these vary).
d) who is butchering the pig. If we do it, it will be a cheaper price per kg than if it is done by a local master butcher.
e) the cost of basic foodstuffs for the animals themselves.
I'd say this is a 'rounded picture', or at least, my rounded picture. Another person may have different ways of doing it, such as the person whose boar we borrow. She has ALL finishers from their 8 sows made into sausages (plain) and sells them frozen from the farm gate for £5 a bag which weighs about 750g... There is nothing that affects the price she charges for her meat! Or hasn't been for some time. And they produce a hell of a lot of sausages between the 8 sows and 2 boars
Which firm do you work for? In what sort of quantities are the clients likely to be buying meats, I wonder? It'd be interesting to hear more about the reports as and when you write them - we might learn something from them too