Level and pattern of winter concentrate allocation in dairy cows: results in first lactation cows

Abstract

AbstractA total of 148 dairy cows in their first lactation and with a mean calving date of 6 December were used in a 4–year experiment. The experiment was designed to examine the effect of level and distribution of concentrate given during the winter period in addition to grass silage (ad libitum) and hay (4 kg/day) on total lactation performance. Each year 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)). Concentrate allocation was individually pre-determined according to expected milk production. During summer, all animals grazed together as a single group. During the experimental period (weeks 4 to 18 of lactation), concentrate and roughage intakes were 6·3, 5·0 and 3·6 kg dry matter (DM) per day and 9.;5, 9·6 and 10·0 kg DM per day in group HS, MS and LS respectively. Milk yield and protein concentration of group HS were higher than that of group MS (+1·3 kg I 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 supply 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 difference between groups S and F.