Only the experience can tell and so far all experiments done in Switzerland and France with the best raw milk from entirely grass fed cows, goats or sheep (AFAIK none of us has ever been able to get milk from a wild animal) have been a disaster.
Like all experiments there are always wild cards that are impossible to factor out completely. A better example would have been the Swiss people that Weston Price visited back about 100 years ago before the people were infested by the diets of outsiders...
Here is an excerpt from this page
http://www.westonaprice.org/thumbs-up-reviews/nutrition-and-physical-degeneration about the fifth paragraph.
"The diets of the healthy "primitives" Price studied were all very different: In the Swiss village where Price began his investigations, the inhabitants lived on rich dairy products--unpasteurized milk, butter, cream and cheese--dense rye bread, meat occasionally, bone broth soups and the few vegetables they could cultivate during the short summer months. The children never brushed their teeth--in fact their teeth were covered in green slime--but Price found that only about one percent of the teeth had any decay at all. The children went barefoot in frigid streams during weather that forced Dr. Price and his wife to wear heavy wool coats; nevertheless childhood illnesses were virtually nonexistent and there had never been a single case of TB in the village."
Another interesting section
"Price took samples of native foods home with him to Cleveland and studied them in his laboratory. He found that these diets contained at least four times the minerals as the American diet of his day. Price would undoubtedly find a greater discrepancy in the 1990s due to continual depletion of our soils through industrial farming practices. What's more, among traditional populations, grains and tubers were prepared in ways that increased vitamin content and made minerals more available--soaking, fermenting, sprouting and sour leavening.
It was when Price analyzed the fat soluble vitamins that he got a real surprise. The diets of healthy native groups contained at least ten times more vitamin A and vitamin D than the American diet of his day! These vitamins are found only in animal fats--butter, lard, egg yolks, fish oils and foods with fat-rich cellular membranes like liver and other organ meats, fish eggs and shell fish.
Price describes the fat soluble vitamins as "catalysts" or "activators" upon which the assimilation of all the other nutrients depended--protein, minerals and vitamins. In other words, without the dietary factors found in animal fats, all the other nutrients largely go to waste.
In Nutrition and Physical Degeneration, Price discusses another fat soluble vitamin that was a more powerful catalyst for nutrient absorption than vitamins A and D. He called it "Activator X". All the healthy groups Price studied had the X Factor in their diets. It could be found in certain special foods which these people considered sacred--cod liver oil, fish eggs, organ meats and the deep yellow Spring and Fall butter from cows eating rapidly growing green grass. When the snows melted and the cows could go up to the rich pastures above their village, the Swiss placed a bowl of such butter on the church altar and lit a wick in it. The Masai set fire to yellow fields so that new grass could grow for their cows. Hunter-gatherers always ate the organ meats of the game they killed--often raw. Liver was held to be sacred by many African tribes. The Eskimos and many Indian tribes put a very high value on fish eggs. Activator X is now believed to be the fat-soluble vitamin K2; read Chris Masterjohn's article to see how this 60-year mystery was finally solved."
I suggest reading the full article if you have the time.
