More about ACV and PH:
Apple Cider Vinegar has been defined with "antibacterial properties". This does not mean that it inhibits or kills bacteria. ACV it's self has no ability to kill anything. ACV has many qualities about it, however the main reason it is used is to raise the PH of the body. Using ACV to raise PH doesn't happen over night and can take weeks or months of constant use to raise the ph from acid to alkaline. It is the long term, or on and off use of it that changes the body. And it is this changing of the ph that gives it this term of having "antibacterial properties".
You have heard the saying, "you are what you eat". If you were to only consume meats, starches, oils and dairy products, and all these are considered highly acidic foods, your body's ph level would be quite low. Adding certain veggies and fruits to your diet helps to balance things and keep your ph closer to 7 or higher on the scale, 7 being neutral. Hence the reason they are always pushing those dreaded fruits and veggies on us! LOL You would become quite sick if your body's ph dropped too much below 5 or 4 on the ph scale. Our bodies need a slightly higher ph balance to stay healthy. Along with the foods we eat, our environment, stress and health can effect the ph of our bodies.
So it is the raising of the ph in your body with certain foods, including ACV, this is where having these antibacterial properties comes from. Pathogens can not survive in extremely high alkaline environments. There are even studies being done with cancer cells and they are finding that they too do not survive in high alkaline environments. Science is looking further into the use of baking soda, which is extremely high in ph, and the effects it may have on cancerous tumors. I am sure at these very high levels, even good bacteria would be killed off in our bodies as well. However it would take very high amounts over very long periods of time to raise the ph so high that it would kill off all bacteria.
So, all this being said, using ACV is an attempt to raise the ph of a body, and this includes our poultry, so that it is more resistant to these harmful pathogens. The body it's self is responsible for killing off the bacterias, not the ACV.
ACV, many fruits and veggies are not all that high on the ph scale and some are even considered acidic. But after the body processes these foods, the chemical reactions from these foods raise the ph.
And what does all this have to do with our poultry? It works the same in the bodies of our birds. If they are not all that healthy, looking poorly or we just want to help keep them healthy, adding ACV to the diet a few times a month, over time, will keep the ph balanced in their bodies and hopefully help ward off dangerous pathogens that might weaken or even kill our birds. Sickness and disease occurs in low ph environments.