Effect of chestnut tannin in the diet of lactating ewes on milk and cheese quality

A commercial product consisting of pure soluble tannins extracted from chestnut wood was introduced into the diet of lactating ewes at pasture, at the level of 20 g / head / day in the concentrate mixed feed. The supplementation with tannins did not exert any influence on milk yield and on lactose and fat content of milk, but induced an increase in milk protein yield, apparently in heat coagulable proteins. This is maybe due to an increase of the rumen undegradable fraction of dietary proteins. The somatic cells count and the bacterial load of milk were not affected as well. Further studies are needed to confirm these important results, in order to optimize the nitrogen metabolic balance of ruminant animals, among the other advantages.