EN
This article briefly reviews the effect of diet composition and structure on the anatomy and function of the rumen and small intestine in young growing calves. The biologically active components present in colostrum and whole milk (including active peptides and proteins, hormones, amino acid derivatives, enzymes, growth factors) promote a rapid development of the digestive tract (in particular the intestines) in newborn calves. Fast rumen development is observed in calves fed diets with a high starch content in the pre-weaning period. Volatile fatty acids (butyric acid and propionic acid) stimulate both the growth of rumen papillae and mucosal metabolic function. Early feeding of starter diets with a distinct physical structure (resulting from the inclusion of whole cereal grains) has a beneficial influence on selected morphometric parameters of the rumen and small intestine. There is no doubt that feed additives and supplements (probiotics, prebiotics and others) contribute to the development of the gastrointestinal tract in calves.