Amorfirelady answered very similarly to how I would in several ways. Here are my responses, take them for what they are worth:
To a 5G bucket how much feed grain do you add (since it swells) 1/2, 3/4?
Depending on the type of feed you are using, you will see differing results on the swelling. The best bet is to start off with about 1/4 of your bucket filled with feed and just top it off with water. I'd start this on a day you do not have to work or be elsewhere for extended periods of time. Keep an eye on it and stir it a few times throughout the day to help it process. You will see it swell as it incorporates the water. Just keep adding water as it does. Once you exceed its capacity to hold water, you can then top it up with an extra inch or water (as many do) or let it ferment 'dry' which is at the point of full absorption (which others do). I, personally, use the excess water method. You now know exactly how much space your feed is going to take to reach full soak, fermentation readiness. You can then adjust how much feed you add to your bucket to successfully ferment what you need for your birds.
How much ACV is added(many different opinions)?
You don't need much. As stated above, 1 tbsp/ gallon is effective. Honestly, 1 tbsp in an entire 5 gallon bucket is potentially effective, just depending on how long you let it sit before you start using it the first time. I've also tried with an entire bottle of ACV with mother, and it's worked fine as well......certainly smells strongly of vinegar at that point; but, it's worked and not retarded the fermentation (if using a yeast/starter).
What is the typical grain/feed mixture(cost effective)?
The cost effective part is going to depend on a few factors - not least of which is your area. Second would be your preference for feed. Some prefer to mix their own and live near a mill who will mix for them (way cost effective). Some prefer to mix their own and have to buy bulk at a whole-foods type store (not so cost effective). Some purchase standard feeds and scratches (like Purina) and do a ration of them (depending on the area, can be pretty effective cost wise). Some prefer to buy non-gmo, non-soy, organic feeds and grains and do a ration of them (not particularly cost effective). The ratio of feed to grain is going to depend on the protein and nutrient levels found in the feed being fermented. Fermentation, while it increases proteins and probiotics and various nutrients, also reduces certain nutrients. If you are using it for layers - as it looks like you are - you may want to consider this as layers have a much longer lifecycle than meat birds.
Because of this, you are going to want to be careful about the extent of protein increase that you are providing. Excessive protein will shorten the life of your bird due to the stress it puts on their system. Just as it does for humans and reptiles, etc. Generally speaking, fermentation will increase the protein content of feed by ~3%. That's a generality. It really depends on what's in the feed; but, I use this as an "eyeball" factor when figuring out my ratios for my layers. I try to keep my protein levels no higher than 21% for my layers. I ferment for them for the reduced feed waste, increased nutrient and health benefits.
The best way, I've found, to figure out my ratios for ensuring protein levels I want is
this. A spreadsheet with the equations in it lets me plug in the nutritional information I want, tweak the parts until I get the overall result in the range I am desiring. Realize, though, you have to pay attention to all the nutritional factors important to your birds, not just the protein. That's why many (most) use a feed in addition to whatever supplements because they know the calculations for all the nutrients have been done already. That equation for figuring out CP, however, will work just as well for the rest of the nutrients, if you're of such a mind to track down all the information and calculate it.
How long is a 5G bucket last say 20 laying birds?
A five gallon bucket, half full, feeds my 38 birds (in the morning)....that's drained.
I feed my free rangers in the morning only. My confined birds get fed in the morning and in the afternoon. There are ~24 birds in my run and they go through about 1.25 gallons of drained FF in half a day. These are estimations, since I'm just eyeballing what's in the bucket. Also, I feed forage and have a dry mix free choice available to my birds.
Really, it's going to depend on your birds. On the nutrients they are deriving from what you are using to ferment, as well as whatever supplemental feed they are receiving.
And, as Amor stated, since we are constantly reusing the hooch....once you get it going the bucket should "never run dry"...
Why brewers yeast and molasses added, is it if its not fermenting fast enough or added bonus?
Using active yeast to kick start is just dependent on the individual fermenter...and, their environment. Many do not use yeast at all. Some do open bucket fermentation (yours truly) which encourages wild yeast colonies. Others do LAB fermentation in an anaerobic environment (sealed) that discourages yeast and instead uses lactic acid for their fermentation. All of them are totally viable ways to ferment (and some are done simultaneously as LABs do not require an anaerobic environment). It's all up to personal preference, in the end.
Molasses is full of micro and macro nutrients, as is the brewer's yeast nutritional supplement. Molasses is often added to organic feeds in its dried form because of this - and, that's also why you will find brewer's yeast in a lot of dog and cat foods.
Also, everyone, please....be clear when you are talking about "Brewer's Yeast". The brewer's yeast
nutritional supplement sold in grocery stores is just that. The majority of the yeast that is sold as a nutritional supplement is a
deactivated yeast. If you are using it, great. It does nothing for your fermentation, however. It would be best suited to add it after the fermentation, just prior to feeding, in my opinion (which is just that, my opinion). It gains nothing from fermentation and is such a fine powder that you wind up leaving a lot of the benefit behind in the hooch. Sure, the feed absorbs some of it; but, the majority of the benefits of the powder is lost. If you mix it in after you have drained your FF, you are getting much more bang for your buck.
Yes, there are two kinds of "brewer's yeast" out there. Just be aware. There's no harm in either one; but, the uses are a bit different depending.
How much of each?
You do not want to use a lot of molasses. And, if your feed already has molasses in it (check the ingredients), I'd really not suggest adding any more. Molasses is not a necessity; and, too much can cause runny pooh. I'd really only suggest adding it if a) you are mixing your own feed and really need the micro-macro nutrients you can get from molasses, or b) you need some assistance in kick starting your fermentation - the sugars from molasses release more quickly than grains/seeds and are thus easier for the yeasts to 'eat', so it's a good assist to them. If you are doing that, I'd add no more than tbsp per gallon of fermented feed. And, honestly, one tbsp per five gallons of feed would be sufficient if you're just using it as an assist to your yeast.
Yeast - activated - only needs a small amount to get started. 1 tbsp is more than enough. I've started with 1/2 tsp in the past. Yes, I play around with this to see what does and doesn't work and what the results are of each variable. I find I prefer the wild yeasts, though the smell is quite a bit different than using the various purchased, active yeasts.
Yeast - nutritional supplement - about 2 tbsp per gallon of drained feed should give you the vitamin boost you are wanting.
For my layers:
I use a feed + scratch mix of 2:1 for a total ferment result of ~20%. I then take that and mix in a mixture of kefir, mealworms and brewer's yeast (nutritional supplement). That mix is 2:2:1 and results in ~26% cp. I then mix together so that my overall cp is ~20.5% (96
% FF + 4% supplement).
