EN
The experiment was carried out on 32 cows of Black and White breed in the State Centre of Breeding at Cerkwica, in the farm Karnica in the period from 14 Dec., 87 to 5 Feb., 88 ie. 54 days. The animals were divided into 4 groups by the method of analogues where the basic fodder was grass silage and hay covering together with additionals production of about 10 kg of milk. In particular groups were applied the following additionals: I - control II - dried sugar beet pulp, III - ryegrass meal IV - maize meal. The greatest decline in milk production was in the first group; in other groups only slight decrease was observed although the cows were after peak of lactation. During the experiment an average milk yield was high and similar in all groups. Feed consumption of 1 kg of milk was low. The level of analysed indicies and elements in blood serum were physiologically almost normal.