The most frequent memory of my fathers' mother is that of her churning butter, and the sweet/sour creaminess of the leftover buttermilk.
Buttermilk today is most often made with bacterial cultures and skim milk, making it a good substitute for yogurt and it has been a staple in my dogs' diets for years.
I once attended a long dog show circuit where Parvo was rampant. At that time, the vaccine had not been brought to market and there was little we could do to protect our dogs from this devastating man made disease.
My vet, Mark Ingram D.V.M. (recently named best Holistic Veterinarian by an area pet magazine) had told me that the disease could not take hold if the friendly bacteria count in the intestinal tract was high. We had traveled up to the Ravenna dog shows and were outdoors where I hoped the fresh air would make it less likely that the disease would spread, but it was not to be. For some of my friends and competitors, the ride back south took days and days because of stopovers for emergency fluids and treatments for Parvo.
Some of those dogs never made it home. It was a heartbreaking time, I recall spending hours on the phone offering condolences and entries at the shows dropped dramatically for fear of contracting Parvo. My own dogs and those I showed remained safe and I attribute that to buttermilk. At the shows, I would give small drinks of buttermilk all day long, mixed with slippery elm tree bark powder, it was a cooling pick me up for the dogs on a long hot circuit. And the dogs came home as healthy as they left.