Effect of corn silage substitution with barley silage on milk production and composition

Water is becoming a restricted resource. This case could represent a problem for the Po valley agro-livestock system, that is based on corn farm production requiring large amounts of irrigation water. Increase in temperatures and the lack of rainfall imposed to study a new system based upon a sustainable use of water resources, by the introduction in dairy cows diet of crops like autumn-winter cereals characterized by low water requirements. Aim of this study was to evaluate the effect of a partial and total corn substitution with barley in dairy cows diets on milk production and composition. Twenty Italian Friesian cows, chosen between 80 animals, were blocked according to parity, DIM and milk yield before the start of the trial and were divided in two groups. Two trials were carried out according to a change-over 2x2 design with two period of 4 weeks each. In trial 1 treatments were corn silage (CS1) with corn silage as forage source, barley silage (BS1) with corn silage in combination with barley silage, whereas in trial 2 treatments were corn silage (CS2) with corn silage as forage source and barley silage (BS2) with barley silage as forage source. The partial and total corn substitution with barley had no effect on milk yield while milk fat percentage and milk urea content increased.