Abstract

The main objective of this research was to study the effect of rations containing full-fat extruded soybeans or fat-extracted heat treated soybean meal, in the nutrition of dairy cows during the period of middle lactation. The study was carried out with two groups of 15 Holstein cows. The animal’s health was controlled on the basis of body condition score, results in production, general condition of animals and some of the most important biochemical parameters of blood serum. In the case of nutrition based on rations where the total amount of soybeans was extruded or where it was partially replaced with fat-extracted heat treated soybean meal, the production of 4% fat corrected milk was 28.43 and 28.78 kg. Observed differences were not statistically significant (p > 0.05). The differences in the achieved average content of milk fat (3.38 and 3.45%) and protein (3.48 and 3.48%) were not statistically significant (p > 0.05). Results of this work shows that the partial replacement of full-fat extruded soybeans with soybeans based products with lower oil content gave better production results of cows during the period of middle lactation.

Key words: Soybeans, dairy cows, biochemical parameters of blood, ruminal content.