Key is heat stress in summer....I guess.....I dunno.The first part says, ACV increases calcium absorption but then it says, the acidity inhibits calcium absorption. So which is it?
Maybe @ChickenCanoe knows if the scratch and peck web page that @GC-Raptor posted is valid.
IMO using ACV is a bit of a 'fad' and often mis- and/or over-used and over promoted.
Many do not understand that it's Active Cider Vinegar that can help with adding probiotics to the diet.