LEVEL AND PATTERN OF WINTER CONCENTRATE ALLOCATION IN DAIRY-COWS - RESULTS IN 1ST LACTATION COWS

A total of 148 dairy cows in their first lactation and with a mean cal ving date of 6 December were used in a 4-year experiment. The experime nt was designed to examine the effect of level and distribution of con centrate given during the winter period in addition to grass silage (a d libitum) and hay (4 kg/day) on total lactation performance. Each yea r the same five treatments were compared: three levels of concentrate supply during the winter period (H, M and L), and, for levels M and L, two different allocation patterns (standard (S) or flat rate (F)). Co ncentrate allocation was individually pre-determined according to expe cted milk production. During summer, all animals grazed together as a single group. During the experimental period (weeks 4 to 18 of lactati on), concentrate and roughage intakes were 6.3, 5.0 and 3.6 kg dry mat ter (DM) per day and 9.5, 9.6 and 10.0 kg DM per day in group HS, MS a nd LS respectively. Milk yield and protein concentration of group HS w ere higher than that of group MS (+1.3 kg/day and +1.0 g/kg) or LS (+3 .0 kg/day and +1.7 g/kg). During winter, live-weight changes were +4, -26 and -39 kg for group HS, MS and LS respectively. Over the 40 weeks of lactation, the differences in milk production and concentrate supp ly were 193 kg and 196 kg DM between groups HS and MS, and 518 kg and 413 kg DM between groups HS and LS. There was no significant differenc e between groups S and F.