The effect of rolled rape seeds on milk composition and lactational responses

Forty-five multiparous cows (74-146 d after calving) were blocked into 3 gr oups of 15 animals on the basis of calving date and milk yield. Within each group the cows were allotted at random to treatment sequences in a 3x3 Lat in square design. Cows were fed a ration composed of pasture, maize silage and meadow hay. Treatments were: control (CK), 6 kg concentrate without rol led rape seeds (WRS), MR - 5 kg concentrate and 0.7 kg WRS and HR - 4 kg co ncentrate and 1.4 kg WRS. The administration of 1.4 kg (HR) rolled rape see ds per cow insignificantly increased the daily milk yield by 1.2 kg and mil k fat content. Supplemental fat tended to nonsignificantly decrease the per centage protein content in milk (CK, 3.10, MR, 3.03, HR, 3.04), but the tot al daily protein production was not affected by treatment. Rolled rape seed s affected the fatty acid composition of milk fat. There was a significant (P<0.05) increase of C 18:1 and C 18:3 content as a result of adding WRS, b ut no effect on C 18:2 concentration.